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106 Cards in this Set
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Write detailed note on bones of the pelvis |
Right and left hip bones(coxal bones; pelvic bones): large, irregularly shaped bones, each of which develops from the fusion of three bones, the ilium, ischium, and pubis.
• Sacrum:formed by the fusion of five, originally separate, sacral vertebrae.
The internal (medial or pelvic) aspects of the hip bones bound the pelvis, forming its lateral walls; these aspects of the bones are emphasized here.
Their external aspects, primarily involved in providing attachment for the lower limb muscles, a
In infants and children, the hip bones consist of three separate bones that are united by a triradiate cartilage at the acetabulum the cup-like depression in the lateral surface of the hip bone, which articulates with the head of the femur.
After puberty, the ilium, ischium, and pubis fuse to form the hip bone.
The two hip bones are joined anteriorly at the pubic symphysis (L. symphysis pubis) and articulate posteriorly with the sacrum at the sacroiliac joints to form the pelvic girdle.
The ilium is the superior, fan-shaped part of the hip bone
The ala, or wing, of the ilium represents the spread of the fan, and the body of the ilium, the handle of the fan.
On its external aspect, the body participates in formation of the acetabulum.
The iliac crest, the rim of the fan, has a curve that follows the contour of the ala between the anterior and the posterior superior iliac spines.
The anteromedial concave surface of the ala forms the iliac fossa
Posteriorly, the sacropelvic surface of the ilium features an auricular surface and an iliac tuberosity, for synovial and syndesmotic articulation with the sacrum, respectively.
The ischium has a body and ramus (L. branch).
The body of the ischium helps form the acetabulum and the ramus of the ischium forms part of the obturator foramen.
The large posteroinferior protuberance of the ischium is the ischial tuberosity.
The small pointed posteromedial projection near the junction of the ramus and body is the ischial spine.
The concavity between the ischial spine and the ischial tuberosity is the lesser sciatic notch.
The larger concavity, the greater sciatic notch, is superior to the ischial spine and is formed in part by the ilium.
The pubis is an angulated bone with a superior ramus, which helps form the acetabulum, and an inferior ramus, which helps form the obturator foramen.
A thickening on the anterior part of the body of the pubis is the pubic crest, which ends laterally as a prominent swelling, the pubic tubercle.
The lateral part of the superior pubic ramus has an oblique ridge, the pecten pubis (pectineal line of pubis).
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What is pelvic inlet? |
The pelvis is divided into greater (false) and lesser (true) pelves by the oblique plane of the pelvic inlet (superior pelvic aperture)
The bony edge (rim) surrounding and defining the pelvic inlet is the pelvic brim, formed by the:
• Promontory and ala of the sacrum (superior surface of its lateral part, adjacent to the body of the sacrum).
•A right and left linea terminalis (terminal line) together form a continuous oblique ridge consisting of the:
• Arcuate line on the inner surface of the ilium.
• Pecten pubis (pectineal line) and pubic crest, forming the superior border of the superior ramus and body of the pubis. |
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What is pubic arch? |
The pubic arch is formed by the ischiopubic rami (conjoined inferior rami of the pubis and ischium) of the two sides
These rami meet at the pubic symphysis, their inferior borders defining the subpubic angle .
The width of the subpubic angle is determined by the distance between the right and the left ischial tuberosities, which can be measured with the gloved fingers in the vagina during a pelvic examination. |
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What is Pelvic outlet? |
The pelvic outlet (inferior pelvic aperture) is bounded by the
• Pubic arch anteriorly.
• Ischial tuberosities laterally.
•Inferior margin of the sacrotuberous ligament(running between the coccyx and the ischial tuberosity) posterolaterally.
• Tip of the coccyx posteriorly. |
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What is greater pelvis? |
It is pelvis Superior to the pelvic inlet.
•Bounded by the iliac alae posterolaterally
the anterosuperior aspect of the S1 vertebra posteriorly.
•Occupied by abdominal viscera (e.g., the ileum and sigmoid colon). |
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Introduce lesser pelvis |
The lesser pelvis (true pelvis) is the part of the pelvis:
•Between the pelvic inlet and the pelvic outlet.
•Bounded by the pelvic surfaces of the hip bones, sacrum, and coccyx.
•That includes the true pelvic cavity and the deep parts of the perineum (perineal compartment), specifically the ischioanal fossae
•That is of major obstetricaland gynecological significance
The concave superior surface of the musculofascial pelvic diaphragm forms the floor of the true pelvic cavity, which is thus deepest centrally.
The convex inferior surface of the pelvic diaphragm forms the roof of the perineum, which is therefore shallow centrally and deep peripherally.
Its lateral parts (ischioanal fossae) extending well up into the lesser pelvis.
The terms pelvis, lesser pelvis, and pelvic cavity are commonly used incorrectly, as if they were synonymous terms. |
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What you know about sacroilliac joint? |
The sacroiliac joints are strong, weight-bearing compound joints
consisting of an anterior synovial joint (between the earshaped auricular surfaces of the sacrum and ilium, covered with articular cartilage)
a posterior syndesmosis (between the tuberosities of the same bones)
The auricular surfaces of this synovial joint have irregular but congruent elevations and depressions that interlock
The sacroiliac joints differ from most synovial joints in that limited mobility is allowed, a consequence of their role in transmitting the weight of most of the body to the hip bones.
Weight is transferred from the axial skeleton to the ilia via the sacroiliac ligaments
to the femurs during standing,
to the ischial tuberosities during sitting.
As long as tight apposition is maintained between the articular surfaces, the sacroiliac joints remain stable.
Unlike a keystone at the top of an arch, the sacrum is actually suspended between the iliac bones and is firmly attached to them by posterior and interosseous sacroiliac ligaments .
The thin anterior sacroiliac ligaments are merely the anterior part of the fibrous capsule of the synovial part of the joint
The abundant interosseous sacroiliac ligaments (lying deep between the tuberosities of the sacrum and ilium and occupying an area of approximately 10 cm2) are the primary structures involved in transferring the weight of the upper body from the axial skeleton to the two ilia of the appendicular skeleton
The posterior sacroiliac ligaments are the posterior external continuation of the same mass of fibrous tissue
Because the fibers of the interosseous and posterior sacroiliac ligaments run obliquely upward and outward from the sacrum, the axial weight pushing down on the sacrum actually pulls the ilia inward (medially) so that they compress the sacrum between them, locking the irregular but congruent surfaces of the sacroiliac joints together
The iliolumbar ligaments are accessory ligaments to this mechanism
Inferiorly, the posterior sacroiliac ligaments are joined by fibers extending from the posterior margin of the ilium (between the posterior superior and posterior inferior iliac spines) and the base of the coccyx to form the massive sacrotuberous ligament
This ligament passes from the posterior ilium and lateral sacrum and coccyx to the ischial tuberosity, transforming the sciatic notch of the hip bone into a large sciatic foramen.
The sacrospinous ligament, passing from lateral sacrum and coccyx to the ischial spine, further subdivides this foramen into greater and lesser sciatic foramina.
Most of the time, movement at the sacroiliac joint is limited by interlocking of the articulating bones and the sacroiliac ligaments to slight gliding and rotary movements
When landing after a high jump or when weightlifting in the standing position, exceptional force is transmitted through the bodies of the lumbar vertebrae to the superior end of the sacrum.
Because this transfer of weight occurs anterior to the axis of the sacroiliac joints, the superior end of the sacrum is pushed inferiorly and anteriorly.
However, rotation of the superior sacrum is counterbalanced by the strong sacrotuberous and sacrospinous ligaments that anchor the inferior end of the sacrum to the ischium, preventing its superior and posterior rotation By allowing only slight upward movement of the inferior end of the sacrum relative to the hip bones, resilience is provided to the sacroiliac region when the vertebral column sustains sudden increases in force or weight. |
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Write a short note on pubic symphysis |
This secondary cartilaginous joint consists of a fibrocartilaginous interpubic disc and surrounding ligaments uniting the bodies of the pubic bones in the median plane The interpubic disc is generally wider in women. The ligaments joining the bones are thickened at the superior and inferior margins of the symphysis, forming superior and inferior pubic ligaments. The superior pubic ligament connects the superior aspects of the pubic bodies and interpubic disc, extending as far laterally as the pubic tubercles. The inferior (arcuate) pubic ligamentis a thick arch of fibers that connects the inferior aspects of the joint components, rounding off the subpubic angle as it forms the apex of the pubic arch The decussating, fibers of the tendinous attachments of the rectus abdominis and external oblique muscles also strengthen the pubic symphysis anteriorly |
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Write about lambosacral joint |
L5 and S1 vertebrae articulate at the anterior intervertebral (IV) joint formed by the L5/S1 IV disc between their bodies and at two posterior zygapophysial joints (facet joints) between the articular processes of these vertebrae The facets on the S1 vertebra face posteromedially, interlocking with the anterolaterally facing inferior articular facets of the L5 vertebra, preventing the lumbar vertebra from sliding anteriorly down the incline of the sacrum. These joints are further strengthened by fan-like iliolumbar ligaments radiating from the transverse processes of the L5 vertebra to the ilia |
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What you know about sacrococygeal joint? |
The sacrococcygeal joint is a secondary cartilaginous joint with an IV disc. Fibrocartilage and ligaments join the apex of the sacrum to the base of the coccyx. The anterior and posterior sacrococcygeal ligaments are long strands that reinforce the joint. |
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Enumerate the viscera present in pelvic cavity |
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What you know about peritoneum of pelvic cavity? |
The parietal peritoneum lining the abdominal cavity continues inferiorly into the pelvic cavity but does not reach the pelvic floor. Instead, it reflects onto the pelvic viscera, remaining separated from the pelvic floor by the pelvic viscera and the surrounding pelvic fascia .
Except for the ovaries and uterine tubes, the pelvic viscera are not completely ensheathed by the peritoneum, lying inferior to it for the main part.
Only their superior and superolateral surfaces are covered with peritoneum. Only the uterine tubes (except for their ostia, which are open) are intraperitoneal and suspended by a mesentery.
The ovaries, although suspended in the peritoneal cavity by a mesentery, are not covered with glistening peritoneum; instead a special, relatively dull epithelium of cuboidal cells (germinal epithelium) covers them.
A loose areolar (fatty) layer between the transversalis fascia and the parietal peritoneum of the inferior part of the anterior abdominal wall allows the bladder to expand between these layers as it becomes distended with urine.
The region superior to the bladder is the only site where the parietal peritoneum is not firmly bound to the underlying structures.
Consequently, the level at which the peritoneum reflects onto the superior surface of the bladder, creating the supravesical fossa is variable, depending on the fullness of the bladder.
When the peritoneum reflects from the abdominopelvic wall onto the pelvic viscera and fascia, a series of folds and fossae is created
In the female, as the peritoneum at or near the midline reaches the posterior border of the roof of the bladder, it reflects onto the anterior aspect of the uterus at the isthmus of the uterus thus it is not related to the anterior vaginal fornix, which is subperitoneal in location. The peritoneum passes over the fundus and descends the entire posterior aspect of the uterus onto the posterior vaginal wall before reflecting superiorly onto the anterior wall of the inferior rectum (rectal ampulla). The “pocket” thus formed between the uterus and the rectum is the rectouterine pouch (cul-de-sac of Douglas)
The median rectouterine pouch is often described as being the inferiormost extent of the peritoneal cavity in the female, but often its lateral extensions on each side of the rectum, the pararectal fossae, are deeper.
Prominent peritoneal ridges, the rectouterine folds, formed by underlying fascial ligaments demarcate the lateral boundaries of the pararectal fossae .
As the peritoneum passes up and over the uterus in the middle of the pelvic cavity, a double peritoneal fold, the broad ligament of the uterus, extends between the uterus and the lateral pelvic wall on each side, forming a partition that separates the paravesical fossae and pararectal fossae of each side.
The uterine tubes, ovaries, ligaments of the ovaries, and round ligaments of the uterus are enclosed within the broad ligaments.
the female the pelvic peritoneal cavity communicates with the external environment via the uterine tubes, uterus, and vagina.
In males and in females who have had a hysterectomy (removal of the uterus), the central peritoneum descends a short distance (as much as 2 cm) down the posterior surface (base) of the bladder and then reflects superiorly onto the anterior surface of the inferior rectum, forming the rectovesical pouch.
The female rectouterine pouch is normally deeper (extends farther caudally) than the male rectovesical pouch.
In the male, a gentle peritoneal fold or ridge, the ureteric fold, is formed as the peritoneum passes up and over the ureter and ductus (vas) deferens (secretory duct of the testis) on each side of the posterior bladder, separating the paravesical and pararectal fossae; in this regard, it is the male equivalent of the broad ligament.
Posterior to the ureteric folds and lateral to the central rectovesical pouch, the peritoneum often descends far enough caudally to cover the superior ends or superior posterior surfaces of the seminal glands (vesicles) and ampullae of the ductus deferens.
Except for these sites (and the testis in its tunica vaginalis, which is derived from peritoneum), the male reproductive organs are not in contact with the peritoneum.
In both sexes, the inferior third of the rectum is below the inferior limits of the peritoneum (i.e., it is subperitoneal), the middle third is covered with peritoneum only on its anterior surface, and the superior third is covered on both its anterior and its lateral surfaces.
The rectosigmoid junction, near the pelvic brim, is intraperitoneal. |
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What is endopelvic fasciae? |
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What you know about pelvic fasciae? |
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Write abou origin course and termination of internal illiac artrey |
The internal iliac artery is the principal artery of the pelvis, supplying most of the blood to the pelvic viscera and some to the musculoskeletal part of the pelvis; however, it also supplies branches to the gluteal region, medial thigh regions, perineum. Each internal iliac artery, approximately 4 cm long, begins as the common iliac artery and bifurcates into the internal and external iliac arteries at the level of the IV disc between the L5 and S1 vertebrae. The ureter crosses the common iliac artery or its terminal branches at or immediately distal to the bifurcation (see Fig. 3.15). The internal iliac artery is separated from the sacroiliac joint by the internal iliac vein lumbosacral trunk. It descends posteromedially into the lesser pelvis, medial to the external iliac vein and obturator nerve, and lateral to the peritoneum. |
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Enumerate branches of internal illiac artrey |
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Differentiate between prenatal and post natal umbilical artery |
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Differentiate between Male and female pelvic girdle? |
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What you know about veins of pelvic cavity? |
Pelvic venous plexuses are formed by the interjoining veins surrounding the pelvic viscera (Fig. 3.19B & C).
These intercommunicating networks of veins are clinically important.
The various plexuses within the lesser pelvis (rectal, vesical, prostatic, uterine, and vaginal) unite and are drained mainly by tributaries of the internal iliac veins,
but some of them drain through the superior rectal vein into the inferior mesenteric vein of the hepatic portal system (Fig. 3.19A) or through lateral sacral veins into the internal vertebral venous plexus (see Chapter 4).
Additional relatively minor paths of venous drainage from the lesser pelvis include the parietal median sacral vein and, in females, the ovarian veins.
The internal iliac veins form superior to the greater sciatic foramen and lie posteroinferior to the internal iliac arteries.
Tributaries of the internal iliac veins are more variable than the branches of the internal iliac artery with which they share names, but roughly accompany them, draining the same territories that the arteries supply.
However, there are no veins accompanying the umbilical arteries between the pelvis and the umbilicus, and the iliolumbar veins from the iliac fossae of the greater pelvis usually drain into the common iliac veins instead.
The internal iliac veins merge with the external iliac veins to form the common iliac veins, which unite at the level of vertebra L4 or L5 to form the inferior vena cava (Fig. 3.19A).
The superior gluteal veins, the accompanying veins (L. venae comitantes) of the superior gluteal arteries of the gluteal region, are the largest tributaries of the internal iliac veins except during pregnancy, when the uterine veins become larger.
Testicular veins traverse the greater pelvis as they pass from the deep inguinal ring toward their posterior abdominal terminations but do not usually drain pelvic structures. The lateral sacral veins often appear disproportionately large in angiographs. They anastomose with the internal vertebral venous plexus (Chapter 4), providing an alternate collateral pathway to reach either the inferior or superior vena cava. It may also provide a pathway for metastasis of prostatic or ovarian cancer to vertebral or cranial sites. |
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Write about lymphatic drainage of pelvic cavity |
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Discuss pelvic nerves |
The pelvis is innervated mainly by the sacral and coccygeal spinal nerves and the pelvic part of the autonomic nervous system.
The piriformis and coccygeus muscles form a bed for the sacral and coccygeal nerve plexuses
The anterior rami of the S2 and S3 nerves emerge between the digitations of these muscles.
The sacral plexus is located on the posterolateral wall of the lesser pelvis.
The two main nerves arising from the sacral plexus, the sciatic and pudendal nerves, lie external to the parietal pelvic fascia. Most branches of the sacral plexus leave the pelvis through the greater sciatic foramen. The sciatic nerve is the largest nerve in the body. It is formed as the large anterior rami of spinal nerves L4–S3 converge on the anterior surface of the piriformis As it is formed, the sciatic nerve passes through the greater sciatic foramen, usually inferior to the piriformis, to enter the gluteal region. It then descends along the posterior aspect of the thigh to supply the posterior aspect of the thigh and the entire leg and foot. The pudendal nerve is the main nerve of the perineum and the chief sensory nerve of the external genitalia. Accompanied by the internal pudendal artery, it leaves the pelvis through the greater sciatic foramen between the piriformis and coccygeus muscles. It then hooks around the ischial spine and sacrospinous ligament and enters the perineum through the lesser sciatic foramen. The superior gluteal nerve leaves the pelvis through the greater sciatic foramen, superior to the piriformis to supply muscles in the gluteal region . The inferior gluteal nerve leaves the pelvis through the greater sciatic foramen inferior to the piriformis and superficial to the sciatic nerve, accompanying the inferior gluteal artery. Both break up into several branches that enter the deep surface of the overlying gluteus maximus muscle. |
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Introduce obturator nerve |
OBTURATOR NERVE The obturator nerve arises from the anterior rami of spinal nerves L2–L4 of the lumbar plexus in the abdomen (greater pelvis) and enters the lesser pelvis. It runs in the extraperitoneal fat along the lateral wall of the pelvis to the obturator canal, an opening in the obturator membrane that otherwise f ills the obturator foramen. Here it divides into anterior and posterior parts, which leave the pelvis through this canal and supply the medial thigh muscles. No pelvic structures are supplied by the obturator nerve. |
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What is lumbosacral trunk |
At or immediately superior to the pelvic brim, the descending part of the L4 nerve unites with the anterior ramus of the L5 nerve to form the thick, cord-like lumbosacral trunk (see Figs. 3.9D, 3.21, and 3.22). The trunk passes inferiorly, on the anterior surface of the ala of the sacrum, and joins the sacral plexus. |
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Enumerate the nerves of sacral plexus and write their distribution |
1)Sciatic nerve 2)superior Gluteal nerve 3)inferior gluteal nerve 4)nerve to quadratus femorus 5)nerve to obturator internus 6)nerve to levator ani 7)pudendal nerve 8)posterior cutaneous nerve of thigh 9)perforated branch 10)pelvic splanchnic nerve 11)Nerve to priformis |
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Write short note on coccygeal plexus |
The coccygeal plexus is a small network of nerve fibers formed by the anterior rami of S4 and S5 and the coccygeal nerves . It lies on the pelvic surface of the coccygeus and supplies this muscle, part of the levator ani, and the sacrococcygeal joint. The anococcygeal nerves arising from this plexus pierce the coccygeus and anococcygeal ligament to supply a small area of skin between the tip of the coccyx and the anus. |
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What are the routes via which Autonmoic nerves enters pelvis |
Sacral sympathetic trunks: primarily provide sympathetic innervation to the lower limbs. • Periarterial plexuses: postsynaptic, sympathetic, vasomotor fibers to superior rectal,
ovarian, internal iliac arteries and their derivative branches. • Hypogastric plexuses: most important route by which sympathetic fibers are conveyed to the pelvic viscera. Pelvic splanchnic nerves: pathway for parasympathetic innervation of pelvic viscera and descending and sigmoid colon. |
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Discuss Sacral sympathetic trunk |
The sacral sympathetic trunks are the inferior continuation of the lumbar sympathetic trunks Each of the sacral trunks is diminished in size from that of the lumbar trunks and usually has four sympathetic ganglia. The sacral trunks descend on the pelvic surface of the sacrum just medial to the pelvic sacral foramina and converge to form the small median ganglion impar (coccygeal ganglion) anterior to the coccyx. The sacral sympathetic trunks descend posterior to the rectum in the extraperitoneal connective tissue and send communicating branches (gray rami communicantes) to each of the anterior rami of the sacral and coccygeal nerves. They also send small branches to the median sacral artery and the inferior hypogastric plexus. The primary function of the sacral sympathetic trunks is to provide postsynaptic fibers to the sacral plexus for sympathetic (vasomotor, pilomotor, and sudomotor) innervation of the lower limb. |
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Discuss hypogastric plexus |
The hypogastric plexuses (superior and inferior) are networks of sympathetic and visceral afferent nerve fibers.
The main part of the superior hypogastric plexus is a prolongation of the intermesenteric plexus which lies inferior to the bifurcation of the aorta
It carries fibers conveyed to and from the intermesenteric plexus by the L3 and L4 splanchnic nerves.
The superior hypogastric plexus enters the pelvis, dividing into right and left hypogastric nerves, which descend on the anterior surface of the sacrum.
These nerves descend lateral to the rectum within hypogastric sheaths and then spread in a fan-like fashion as they merge with the pelvic splanchnic nerves to form the right and left inferior hypogastric plexuses.
The inferior hypogastric plexuses thus contain both sympathetic and parasympathetic fibers as well as visceral afferent fibers, which continue through the lamina of the hypogastric sheath to the pelvic viscera, upon which they form sub-plexuses collectively referred to as the pelvic plexuses.
In both sexes, sub-plexuses are associated with the lateral aspects of the rectum and inferolateral surfaces of the bladder.
In addition, sub-plexuses in the male are also associated with the prostate and seminal glands.
In females, sub-plexuses are also associated with the cervix of the uterus and the lateral fornices of the vagina. |
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Discuss pelvic splanchnic nerves |
Pelvic splanchnic nerves arise in the pelvis from the anterior rami of spinal nerves S2–S4 of the sacral plexus They convey presynaptic parasympathetic fibers derived from the S2–S4 spinal cord segments, which make up the sacral outflow of the parasympathetic (craniosacral) nervous system, and visceral afferent fibers from cell bodies in the spinal ganglia of the corresponding spinal nerves. The greatest contribution of these fibers is usually from the S3 nerve. The hypogastric/pelvic system of plexuses, receiving sympathetic fibers via lumbar splanchnic nerves and parasympathetic fibers via pelvic splanchnic nerves, innervate the pelvic viscera. Although the sympathetic component largely produces vasomotion as elsewhere, here inhibits peristaltic contraction of the rectum stimulates contraction of the internal genital organs during orgasm, producing ejaculation in the male. Because the pelvis does not include a cutaneous area, pelvic sympathetic fibers do not produce pilomotion or vasomotion functions. The parasympathetic fibers distributed within the pelvis stimulate contraction of the rectum and bladder for defecation and urination, respectively. Parasympathetic fibers in the prostatic plexus penetrate the pelvic floor to reach the erectile bodies of the external genitalia, producing erection. |
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Discuss pelvic splanchnic nerves |
Pelvic splanchnic nerves arise in the pelvis from the anterior rami of spinal nerves S2–S4 of the sacral plexus They convey presynaptic parasympathetic fibers derived from the S2–S4 spinal cord segments, which make up the sacral outflow of the parasympathetic (craniosacral) nervous system, and visceral afferent fibers from cell bodies in the spinal ganglia of the corresponding spinal nerves. The greatest contribution of these fibers is usually from the S3 nerve. The hypogastric/pelvic system of plexuses, receiving sympathetic fibers via lumbar splanchnic nerves and parasympathetic fibers via pelvic splanchnic nerves, innervate the pelvic viscera. Although the sympathetic component largely produces vasomotion as elsewhere, here inhibits peristaltic contraction of the rectum stimulates contraction of the internal genital organs during orgasm, producing ejaculation in the male. Because the pelvis does not include a cutaneous area, pelvic sympathetic fibers do not produce pilomotion or vasomotion functions. The parasympathetic fibers distributed within the pelvis stimulate contraction of the rectum and bladder for defecation and urination, respectively. Parasympathetic fibers in the prostatic plexus penetrate the pelvic floor to reach the erectile bodies of the external genitalia, producing erection. |
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Discuss visceral afferent innervation of pelvis |
Visceral afferent fibers travel with autonomic nerve fibers, although the sensory impulses are conducted centrally, retrograde to the efferent impulses conveyed by the autonomic fibers. All visceral afferent fibers conducting reflexive sensation (information that does not reach consciousness) travel with parasympathetic fibers. Thus, in the case of the pelvis, they travel through the pelvic and inferior hypogastric plexuses and the pelvic splanchnic nerves to the spinal sensory ganglia of spinal nerves S2–S4. The paths followed by visceral afferent fibers conducting pain from the pelvic viscera differ in terms of course and destination, depending on whether the viscus or part of the viscus from which the pain is emanating is located superior or inferior to the pelvic pain line. Except in the case of the alimentary canal, the pelvic pain line corresponds to the inferior limit of the peritoneum (see Table 3.3 figures B & C). Intraperitoneal abdominopelvic viscera, or aspects of visceral structures that are in contact with the peritoneum, are supe |
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Write a note on ureters |
The ureters are muscular tubes, 25–30 cm long, that connect the kidneys to the urinary bladder.
The ureters are retroperitoneal; their superior portions are abdominal
They are inferior continuations of Renal pelvis They are inferior continuations of Renal pelvis They are inferior continuations of Renal pelvis
As the ureters cross the bifurcation of the common iliac artery or the beginning of the external iliac artery they pass over the pelvic brim, thus leaving the abdomen and entering the lesser pelvis .
The pelvic parts of the ureters run on the lateral walls of the pelvis, parallel to the anterior margin of the greater sciatic notch, between the parietal pelvic peritoneum and the internal iliac arteries.
Opposite the ischial spine, they curve anteromedially, superior to the levator ani, and enter the urinary bladder.
The inferior ends of the ureters are surrounded by the vesical venous plexus
The ureters pass obliquely through the muscular wall of the urinary bladder in an inferomedial direction, entering the outer surface of the bladder approximately 5 cm apart,
but their internal openings into the lumen of the empty bladder are separated by only half that distance.
This oblique passage through the bladder wall forms a one-way “flap valve,” the internal pressure of the filling bladder causing the intramural passage to collapse.
In addition, contractions of the bladder musculature act as a sphincter preventing the reflux of urine into the ureters when the bladder contracts, increasing internal pressure during micturition.
Urine is transported down the ureters by means of peristaltic contractions, a few drops being transported at intervals of 12–20 sec
In males, the only structure that passes between the ureter and the peritoneum is the ductus deferens
it crosses the ureter within the ureteric fold of peritoneum.
The ureter lies posterolateral to the ductus deferens and enters the posterosuperior angle of the bladder, just superior to the seminal gland.
In females, the ureter passes medial to the origin of the uterine artery and continues to the level of the ischial spine, where it is crossed superiorly by the uterine artery .
It then passes close to the lateral part of the fornix of the vagina and enters the posterosuperior angle of the bladder. |
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Write a note on Vasculatures of uterus |
The arterial supply to the pelvic parts of the ureters is variable, with ureteric branches extending from the common iliac, internal iliac, and ovarian arteries The ureteric branches anastomose along the length of the ureter forming a continuous blood supply, although not necessarily effective collateral pathways. The most constant arteries supplying the terminal parts of the ureter in females are branches of the uterine arteries. The source of similar branches in males are the inferior vesical arteries. The blood supply of the ureters is a matter of great concern to surgeons operating in the region The venous drainage from the pelvic parts of the ureters generally parallels the arterial supply, draining to veins with corresponding names. Lymphatic vessels pass primarily to common and internal iliac nodes |
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Discuss innervation of ureters |
The nerves to the ureters derive from adjacent autonomic plexuses (renal, aortic, superior and inferior hypogastric).
The ureters are primarily suprior to the pelvic pain line. Afferent (pain) fibers from the ureters follow sympathetic fibers in a retrograde direction to reach the spinal ganglia and spinal cord segments of T11–L1 or L2 Ureteric pain is usually referred to the ipsilateral lower quadrant of the abdomen, especially to the groin.
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Discuss pelvis portion of ureters |
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Arterial supply and venous drainage of pelvic portion of ureters |
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Discuss innervation of pelvic portion ureters |
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Discuss urinary bladder |
1.Introduction 2.Age and position of bladder 3.Empty bladder vs filled bladder 4.parts 5.surfaces 6. Bladder bed 7.musculature of Bladder wall 8.trigone of urinary bladder 9.uuvula
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Blood supply and drainage of urinary bladder |
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Innervation of bladder |
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Discuss urethra |
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Blood supply and drainage of urethra |
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Innervation of urethra |
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Differentiate between male and female urethra |
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Discuss Rectum |
Introduction Origin Termination Junctions Flexures Peritoneal reflections Posterior relations Anterior relation Peretonium on rectal parts Rectal septum Rectal ampula |
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Blood Supply and drainge of rectum |
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Innervation of Rectum |
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Discuss structure of prostate gland |
Introduction Parts Capsule Base Apex Surfaces Lobes Lobules Zones Hormone induced middle lobe Secreation Prostatic duct Arterial supply Venous drainage Lymphatic drainge Innervation The prostate (approximately 2cm ap depth 3 cm length 4cm width) is the largest accessory gland of the male reproductive system
The firm, walnutsize prostate surrounds the prostatic urethra.
The glandular part makes up approximately two thirds of the prostate;
the other third is fibromuscular.
The fibrous capsule of the prostate is dense and neurovascular, incorporating the prostatic plexuses of veins and nerves.
All this is surrounded by the visceral layer of the pelvic fascia, forming a fibrous prostatic sheath
that is thin anteriorly,
continuous anterolaterally with the puboprostatic ligaments,
It is dense posteriorly
where it blends with the rectovesical septum.
The prostate has
•A base closely related to the neck of the bladder.
•An apex that is in contact with fascia on the superior aspect of the urethral sphincter and deep perineal muscles.
•A muscular anterior surface, featuring mostly transversely oriented muscle fibers forming a vertical, trough-like hemisphincter (rhabdosphincter), which is part of the urethral sphincter.
The anterior surface is separated from the pubic symphysis by retroperitoneal fat in the retropubic space.
A posterior surface that is related to the ampulla of the rectum.
•Inferolateral. surfaces that are related to the levator ani .
Although not clearly distinct anatomically, the following lobes of the prostate are traditionally described
•The isthmus of the prostate (commissure of prostate; historically, the anterior “lobe”) lies anterior to the urethra. It is fibromuscular, the muscle fibers representing a superior continuation of the external urethral sphincter muscle to the neck of the bladder, and contains little, if any, glandular tissue.
• Right and left lobes of the prostate, separated anteriorly by the isthmus and posteriorly by a central, shallow longitudinal furrow,
may each be subdivided for descriptive purposes into four indistinct lobules defined by their relationship to the urethra and ejaculatory ducts, and— although less apparent—by the arrangement of the ducts and connective tissue:
(1) an inferoposterior (lower posterior) lobule that lies posterior to the urethra and inferior to the ejaculatory ducts. This lobule constitutes the aspect of the prostate palpable by digital rectal examination.
(2) an inferolateral (lower lateral) lobule directly lateral to the urethra, forming the major part of the right or left lobe.
(3) a superomedial lobule, deep to the inferoposterior lobule, surrounding the ipsilateral ejaculatory duct.
(4) an anteromedial lobule,deep to the inferolateral lobule, directly lateral to the proximal prostatic urethra.
An embryonic middle (median) lobe gives rise to (3) and (4) above.
This region tends to undergo hormone-induced hypertrophy in advanced age, forming a middle lobule that lies between the urethra and the ejaculatory ducts and is closely related to the neck of the bladder. Enlargement of the middle lobule is believed to be at least partially responsible for the formation of the uvula that may project into the internal urethral orifice Some clinicians, especially urologists and sonographers, divide the prostate into peripheral and central (internal) The central zone is comparable to the middle lobe. The prostatic ducts (20–30) open chiefly into the prostatic sinuses that lie on either side of the seminal colliculus on the posterior wall of the prostatic urethra. Prostatic fluid, a thin, milky fluid, provides approximately 20% of the volume of semen (a mixture of secretions produced by the testes, seminal glands, prostate, and bulbourethral glands that provides the vehicle by which sperms are transported) and plays a role in activating the sperms.
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What is arterial supply of prostate |
The prostatic arteries are mainly branches of the internal iliac artery especially the inferior vesical arteries but also the internal pudendal and middle rectal arteries. The veins join to form a plexus around the sides and base of the prostate This prostatic venous plexus, between the fibrous capsule of the prostate and the prostatic sheath, drains into the internal iliac veins. The prostatic venous plexus is continuous superiorly with the vesical venous plexus communicates posteriorly with the internal vertebral venous plexus. |
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Discuss Bulbourethral gland |
The two pea-size bulbourethral glands (Cowper glands) lie posterolateral to the intermediate part of the urethra,
largely embedded within the external urethral sphincter.
The ducts of the bulbourethral glands pass through the perineal membrane with the intermediate urethra and open through minute apertures into the proximal part of the spongy urethra in the bulb of the penis.
Their mucus-like secretion enters the urethra during sexual arousal. |
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Discuss Innervation of internal genital organs of male pelvis |
The ductus deferens, seminal glands, ejaculatory ducts, and prostate are richly innervated by sympathetic nerve fibers. Presynaptic sympathetic fibers originate from cell bodies in the intermediolateral cell column of the T12–L2 (or L3) spinal cord segments. They traverse the paravertebral ganglia of the sympathetic trunks to become components of lumbar (abdominopelvic) splanchnic nerves and the hypogastric and pelvic plexuses Presynaptic parasympathetic fibers from S2 and S3 spinal cord segments traverse pelvic splanchnic nerves, which also join the inferior hypogastric/pelvic plexuses. Synapses with postsynaptic sympathetic and parasympathetic neurons occur within the plexuses, en route to or near the pelvic viscera. As part of an orgasm, the sympathetic system stimulates contraction of the internal urethral sphincter to prevent retrograde ejaculation. Simultaneously, it stimulates rapid peristaltic-like contractions of the ductus deferens, and the combined contraction of and secretion from the seminal glands and prostate that provide the vehicle (semen) and the expulsive force to discharge the sperms during ejaculation. The function of the parasympathetic innervation of the internal genital organs is unclear. However, parasympathetic fibers traversing the prostatic nerve plexus form the cavernous nerves that pass to the erectile bodies of the penis, which are responsible for producing penile erection. |
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Discuss ovaries |
1.Introduction 2. Mesovarium of ovary 3. Tunica albugina of ovary 4. Suspensory ligament of ovary 5. Ovarian ligament 6.Site of discharge of oocyte 7. Ovarian arteries
The ovaries are almond-shaped and -sized female gonads in which the oocytes (female gametes or germ cells) develop.
They are also endocrine glands that produce reproductive hormones.
Each ovary is suspended by a short peritoneal fold or mesentery, the mesovarium.
The mesovarium is a subdivision of a larger mesentery of the uterus, the broad ligament.
tunica albuginea of the ovary
In prepubertal females, it is the connective tissue capsule comprising the surface of the ovary
It is covered by a smooth layer of ovarian mesothelium or surface (germinal) epithelium, a single layer of cuboidal cells that gives the surface a dull, grayish appearance, contrasting with the shiny surface of the adjacent peritoneal mesovarium with which it is continuous
After puberty, the ovarian surface epithelium becomes progressively scarred and distorted because of the repeated rupture of ovarian follicles and discharge of oocytes during ovulation.
The scarring is less in women who have been taking oral contraceptives that inhibit ovulation.
suspensory ligament
The ovarian vessels, lymphatics, and nerves cross the pelvic brim, passing to and from the superolateral aspect of the ovary within a peritoneal fold, the suspensory ligament of the ovary, which becomes continuous with the mesovarium of the broad ligament.
Location Consequently the ovaries are typically found laterally between the uterus and the lateral pelvic wall during a manual or ultrasonic pelvic examination
Ovarian Ligament
Medially within the mesovarium, a short ovarian ligament tethers the ovary to the uterus.
The ovarian ligament is a remnant of the superior part of the ovarian gubernaculum of the fetus The ligament of the ovary connects the proximal (uterine) end of the ovary to the lateral angle of the uterus, just inferior to the entrance of the uterine tube
Site of discharge of oocyte
Because the ovary is suspended in the peritoneal cavity and its surface is not covered by peritoneum, the oocyte expelled at ovulation passes into the peritoneal cavity.
However, its intraperitoneal life is short because it is normally trapped by the fimbriae of the infundibulum of the uterine tube and carried into the ampulla, where it may be fertilized. Ovarian arteries The ovarian artery arises from the abdominal aorta inferior to the renal artery but considerably superior to the inferior mesenteric artery (see Fig. 3.16). As it passes inferiorly, the ovarian artery adheres to the parietal peritoneum and runs anterior to the ureter on the posterior abdominal wall, usually giving branches to it. As the ovarian artery enters the lesser pelvis, it crosses the origin of the external iliac vessels. It then runs medially, dividing into an ovarian branch and a tubal branch, which supply the ovary and uterine tube, respectively These branches anastomose with the corresponding branches of the uterine artery. |
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Uterine tubes |
Introduction Introduction The uterine tubes (formerly called oviducts or fallopian tubes) conduct the oocyte, discharged monthly from an ovary during child-bearing years, from the periovarian peritoneal cavity to the uterine cavity.
They also provide the usual site of fertilization.
The tubes extend laterally from the uterine horns and open into the peritoneal cavity near the ovaries
Mesosalpinx The uterine tubes (approximately 10 cm long) lie in a narrow mesentery, the mesosalpinx, forming the free anterosuperior edges of the broad ligaments.
Location In the “ideal” disposition, as typically illustrated, the tubes extend symmetrically posterolaterally to the lateral pelvic walls, where they arch anterior and superior to the ovaries in the horizontally disposed broad ligament.
In reality, as seen in an ultrasound examination, the tubes are commonly asymmetrically arranged with one or the other often lying superior and even posterior to the uterus.
Parts The uterine tubes are divisible into four parts, from lateral to medial:
(1) Infundibulum: the funnel-shaped distal end of the tube that opens into the peritoneal cavity through the abdominal ostium.
The finger-like processes of the fimbriated end of the infundibulum (fimbriae) spread over the medial surface of the ovary;
one large ovarian fimbria is attached to the superior pole of the ovary.
(2) Ampulla: the widest and longest part of the tube, which begins at the medial end of the infundibulum;
fertilization of the oocyte usually occurs in the ampulla.
3) Isthmus: the thick-walled part of the tube, which enters the uterine horn.
(4) Uterine part: the short intramural segment of the tube that passes through the wall of the uterus and opens via the uterine ostium into the uterine cavity at the uterine horn |
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What is broad ligament of uterus |
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Arterial supply of of ovary and uterine tubes |
The ovarian arteries arise from the abdominal aorta and descend along the posterior abdominal wall. At the pelvic brim, they cross over the external iliac vessels and enter the suspensory ligaments approaching the lateral aspects of the ovaries and uterine tubes. The ascending branches of the uterine arteries (branches of the internal iliac arteries) course along the lateral aspects of the uterus to approach the medial aspects of the ovaries and tubes Both the ovarian and ascending uterine arteries terminate by bifurcating into ovarian and tubal branches, which supply the ovaries and tubes from opposite ends and anastomose with each other, providing a collateral circulation from abdominal and pelvic sources to both structures. |
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Venous drainage of ovary and uterine tubes |
Veins draining the ovary form a vine-like pampiniform plexus of veins in the broad ligament near the ovary and uterine tube . The veins of the plexus usually merge to form a singular ovarian vein, which leaves the lesser pelvis with the ovarian artery. The right ovarian vein ascends to enter the inferior vena cava; the left ovarian vein drains into the left renal vein The tubal veins drain into the ovarian veins and uterine (uterovaginal) venous plexus |
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Innervation of ovaries and uterine tubes |
The nerve supply derives partly from the ovarian plexus, descending with the ovarian vessels, and partly from the uterine (pelvic) plexus The ovaries and uterine tubes are intraperitoneal and, therefore, are superior to the pelvic pain line . Visceral afferent pain fibres Thus visceral afferent pain fibers ascend retrogradely with the descending sympathetic fibers of the ovarian plexus and lumbar splanchnic nerves to cell bodies in the T11–L1 spinal sensory ganglia. Visceral Afferent Reflex fibres Visceral afferent reflex fibers follow parasympathetic fibers retrogradely through the uterine (pelvic) and inferior hypogastric plexuses and the pelvic splanchnic nerves to cell bodies in the S2–S4 spinal sensory ganglia. |
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Uterus |
Introduction The uterus (womb) is a thick-walled, pear-shaped, hollow muscular organ.
The embryo and fetus develop in the uterus.
Its muscular walls adapt to the growth of the fetus and then provide the power for its expulsion during childbirth.
Location The non-gravid (non-pregnant) uterus usually lies in the lesser pelvis, with its body lying on the urinary bladder and its cervix between the urinary bladder and rectum
The uterus is a very dynamic structure, the size and proportions of which change during the various changes of life
The adult uterus is usually anteverted (tipped anterosuperiorly relative to the axis of the vagina) and anteflexed (flexed or bent anteriorly relative to the cervix, creating the angle of flexion) so that its mass lies over the bladder.
Position
Consequently, when the bladder is empty, the uterus typically lies in a nearly transverse plane The position of the uterus changes with the degree of fullness of the bladder and rectum, and stage of pregnancy.
Size
Although its size varies considerably, the non-gravid uterus is approximately 7.5 cm long, 5 cm wide, and 2 cm thick and weighs approximately 90 g.
Parts
The uterus is divisible into two main parts the
1) body 2)cervix.
Body The body of the uterus, forming the superior two thirds of the organ,
includes
1)the fundus of the uterus,
2)the rounded part that lies superior to the uterine ostia
The body lies between the layers of the broad ligament and is freely movable
It has two surfaces:
vesical (related to the bladder) and intestinal.
The body is demarcated from the cervix by the isthmus of the uterus, a relatively constricted segment, approximately 1 cm long
Cervix
The cervix of the uterus is the cylindrical, relatively narrow inferior third of the uterus, approximately 2.5 cm long in an adult non-pregnant woman.
The amount of muscular tissue in the cervix is markedly less than in the body of the uterus.
The cervix is mostly fibrous and is composed mainly of collagen with a small amount of smooth muscle and elastin.
For descriptive purposes, two parts are described:
a supravaginal part between the isthmus and the vagina,
a vaginal part, which protrudes into the vagina
The rounded vaginal part surrounds the external os of the uterus and is surrounded in turn by a narrow recess, the vaginal fornix (anterior and posterior)
The supravaginal part is separated from the bladder anteriorly by loose connective tissue and from the rectum posteriorly by the rectouterine pouch
The slit-like uterine cavity is approximately 6 cm in length from the external os to the wall of the fundus
The uterine horns(L. cornua) are the superolateral regions of the uterine cavity, where the uterine tubes enter.
The uterine cavity continues inferiorly as the cervical canal.
The fusiform canal extends from a narrowing inside the isthmus of the uterine body, the anatomical internal os, through the supravaginal and vaginal parts of the cervix, communicating with the lumen of the vagina through the external os.
The uterine cavity (in particular, the cervical canal) and the lumen of the vagina together constitute the birth canal through which the fetus passes at the end of gestation.
Layers of uterine Wall
The wall of the body of the uterus consists of three coats, or layers:
• Perimetrium—the serosa or outer serous coat—consists of peritoneum supported by a thin layer of connective tissue.
• Myometrium—the middle coat of smooth muscle— becomes greatly distended (more extensive but much thinner) during pregnancy.
The main branches of the blood vessels and nerves of the uterus are located in this coat.
During childbirth, contraction of the myometrium is hormonally stimulated at intervals of decreasing length to dilate the cervical os and expel the fetus and placenta.
During the menses, myometrial contractions may produce cramping.
Endometrium— the inner mucous coat—is firmly adhered to the underlying myometrium.
The endometrium is actively involved in the menstrual cycle, differing in structure with each stage of the cycle.
If conception occurs, the blastocyst becomes implanted in this layer; if conception does not occur, the inner surface of this coat is shed during menstruation.
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Ligaments of uterus |
Externally, the ligament of the ovary attaches to the uterus posteroinferior to the uterotubal junction
It contains ovarian vessels
The round ligament of the uterus (L. ligamentum teres uteri) attaches anteroinferiorly to uterotubal junction.
Round ligament and ovarian ligament are vestiges of the ovarian gubernaculum, related to the relocation of the gonad from its developmental position on the posterior abdominal wall
The uterus is a dense structure located in the center of the pelvic cavity.
The principal supports of the uterus holding it in this position are both passive and active or dynamic.
Dynamic support of the uterus is provided by the pelvic diaphragm.
Its tone during sitting and standing and active contraction during periods of increased intra-abdominal pressure (sneezing, coughing, etc.) is transmitted through the surrounding pelvic organs and the endopelvic fascia in which they are embedded.
Passive support of the uterus is provided by its position—the way in which the normally anteverted and anteflexed uterus rests on top of the bladder.
When intraabdominal pressure is increased, the uterus is pressed against the bladder.
The cervix is the least mobile part of the uterus because of the passive support provided by attached condensations of endopelvic fascia (ligaments), which may also contain smooth muscle (Figs. 3.13 and 3.14):
• Cardinal (transverse cervical) ligaments extend from the supravaginal cervix and lateral parts of the fornix of the vagina to the lateral walls of the pelvis (
• Uterosacral ligaments pass superiorly and slightly posteriorly from the sides of the cervix to the middle of the sacrum; they are palpable during a rectal examination.
Together these passive and active supports keep the uterus centered in the pelvic cavity and resist the tendency for the uterus to fall or be pushed through the vagina. the vagina. |
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What are the parts of broad ligament of uterus? |
mesosalpinx It is a small mesentery in which The uterine tube lies it is present in the anterosuperior free border of the broad ligament, mesovarium Similarly, the ovary lies within a small mesentery called the mesovarium located on the posterior aspect of the broad ligament. Mesometrium The largest part of the broad ligament, inferior to the mesosalpinx and mesovarium, which serves as a mesentery for the uterus itself, is the mesometrium. |
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Discuss broad ligament of uterus |
The broad ligament of the uterus is a double layer of peritoneum (mesentery) that extends from the sides of the uterus to the lateral walls and floor of the pelvis This ligament assists in keeping the uterus in position. The two layers of the broad ligament are continuous with each other at a free edge that surrounds the uterine tube. Laterally, the peritoneum of the broad ligament is prolonged superiorly over the vessels as the suspensory ligament of the ovary. Between the layers of the broad ligament on each side of the uterus, the ligament of the ovary lies posterosuperiorly and the round ligament of the uterus lies anteroinferiorly. |
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Anterior relations of uterus |
Anteriorly (anteroinferiorly in its normal anteverted position): the vesicouterine pouch and superior surface of the bladder; the supravaginal part of the cervix is related to the bladder and is separated from it by only fibrous connective tissue. |
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What are the structures posterior to uterus? |
• Posteriorly: the rectouterine pouch containing loops of small intestine and the anterior surface of rectum; only the visceral pelvic fascia uniting the rectum and uterus here resists increased intra-abdominal pressure. |
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Structures lateral to the uterus |
• Laterally: the peritoneal broad ligament flanking the uterine body and the fascial cardinal ligaments on each side of the cervix and vagina; in the transition between the two ligaments, the ureters run anteriorly slightly superior to the lateral part of the vaginal fornix and inferior to the uterine arteries, usually approximately 2 cm lateral to the supravaginal part of the cervix |
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Structures lateral to the uterus |
• Laterally: the peritoneal broad ligament flanking the uterine body and the fascial cardinal ligaments on each side of the cervix and vagina; in the transition between the two ligaments, the ureters run anteriorly slightly superior to the lateral part of the vaginal fornix and inferior to the uterine arteries, usually approximately 2 cm lateral to the supravaginal part of the cervix |
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Blood supply and drainage of uterus |
The blood supply of the uterus derives mainly from the uterine arteries, with potential collateral supply from the ovarian arteries The uterine veins enter the broad ligaments with the arteries and form a uterine venous plexus on each side of the cervix. Veins from the uterine plexus drain into the internal iliac veins. |
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Vagina |
The vagina, a distensible musculomembranous tube (7–9 cm long), extends from the middle cervix of the uterus to the vaginal orifice, the opening at the inferior end of the vagina The vaginal orifice, external urethral orif lice, and ducts of the greater and lesser vestibular glands open into the vestibule of the vagina, the cleft between the labia minora. The superior end of the vagina surrounds the cervix. The vagina: •serves as a canal for menstrual fluid, •forms the inferior part of the birth canal , receives the penis and ejaculate during sexual intercourse, and •communicates superiorly with the cervical canal and inferiorly with the vestibule of the vagina. The vagina is usually collapsed. The orifice is usually collapsed toward the midline so that its lateral walls are in contact on each side of an anteroposterior slit. Superior to the orifice, however, the anterior and posterior walls are in contact on each side of a transverse potential cavity, H-shaped in cross section except at its superior end where the cervix holds them apart. The vagina lies posterior to the urinary bladder and urethra, the latter projecting into its inferior anterior wall . It lies anterior to the rectum, passing between the medial margins of the levator ani (puborectalis) muscles. The vaginal fornix, the recess around the cervix, has anterior, posterior, and lateral parts The posterior vaginal fornix is the deepest part and is closely related to the rectouterine pouch. Four muscles compress the vagina and act as sphincters: pubovaginalis, external urethral sphincter, urethrovaginal sphincter, bulbospongiosus •anteriorly to the fundus of the urinary bladder and urethra; •laterally to the levator ani, visceral pelvic fascia, and ureters; and •posteriorly (from inferi or to superior) to the anal canal, rectum, and rectouterine pouch. |
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Blood supply and venous drainage of vagina |
The arteries supplying the superior part of the vagina derive from the uterine arteries. The arteries supplying the middle and inferior parts of the vagina derive from the vaginal and internal pudendal arteries The vaginal veins form vaginal venous plexuses along the sides of the vagina and within the vaginal mucosa These veins are continuous with the uterine venous plexus as the uterovaginal venous plexus and drain into the internal iliac veins through the uterine vein. This plexus also communicates with the vesical and rectal venous plexuses. |
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Innervation of vagina and uterus |
Only the inferior one fifth to one quarter of the vagina is somatic in terms of innervation. Innervation of this part of the vagina is from the deep perineal nerve, a branch of the pudendal nerve, which conveys sympathetic and visceral afferent fibers but no parasympathetic fibers Only this somatically innervated part is sensitive to touch and temperature, even though the somatic and visceral afferent fibers have their cell bodies in the same (S2–S4) spinal ganglia. Most of the vagina (superior three quarters to four fifths) is visceral in terms of its innervation. Nerves to this part of the vagina and to the uterus are derived from the uterovaginal nerve plexus, which travels with the uterine artery at the junction of the base of the (peritoneal) broad ligament and the superior part of the (fascial) transverse cervical ligament. The uterovaginal nerve plexus is one of the pelvic plexuses that extends to the pelvic viscera from the inferior hypogastric plexus. Sympathetic, parasympathetic, and visceral afferent fibers pass through this plexus. Sympathetic innervation originates in the inferior thoracic spinal cord segments and passes through lumbar splanchnic nerves intermesenteric-hypogastric-pelvic series of plexuses. Parasympathetic innervation originates in the S2–S4 spinal cord segments and passes through the pelvic splanchnic nerves to the inferior hypogastric-uterovaginal plexus. The visceral afferent innervations of the superior (intraperitoneal; fundus and body) and inferior (subperitoneal; cervical) parts of the uterus and vagina differ in terms of course and destination. Visceral afferent fibers conducting pain impulses from the intraperitoneal uterine fundus and body (superior to the pelvic pain line) follow the sympathetic innervation retrograde to reach cell bodies in the inferior thoracic-superior lumbar spinal ganglia. Afferent fibers conducting pain impulses from the subperitoneal uterine cervix and vagina (inferior to the pelvic pain line) follow the parasympathetic fibers retrograde through the uterovaginal and inferior hypogastric plexuses and pelvic splanchnic nerves to reach cell bodies in the spinal sensory ganglia of S2–S4. The two different routes followed by visceral pain fibers is clinically significant in that it offers mothers a variety of types of anesthesia for childbirth All visceral afferent fibers from the uterus and vagina not concerned with pain (those conveying unconscious sensations) also follow the latter route. |
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What is perinium? |
The perineum refers to a shallow compartment of the body (perineal compartment) superiorly bounded by the pelvic outlet separated from the pelvic cavity by the fascia covering the inferior aspect of the pelvic diaphragm, formed by the levator ani and coccygeus muscles . In the anatomical position, the surface of the perineum—the perineal region—is the narrow region between the proximal parts of the thighs; however, when the lower limbs are abducted, it is a diamondshaped area extending from the mons pubis anteriorly in females, the medial surfaces (insides) of the thighs laterally, and the gluteal folds and superior end of the intergluteal (natal) cleft posteriorly The osseofibrous structures marking the boundaries of the perineum (perineal compartment) (Fig. 3.51A & B) are the: • Pubic symphysis, anteriorly. • Ischiopubic rami (combined inferior pubic rami and ischial rami), anterolaterally. • Ischial tuberosities, laterally. Sacrotuberous ligaments, posterolaterally. •Inferiormost sacrum and coccyx, posteriorly. A transverse line joining the anterior ends of the ischial tuberosities divides the diamond-shaped perineum into two triangles, the oblique planes of which intersect at the transverse line . The anal triangle lies posterior to this line. The anal canal and its orifice, the anus, constitute the major deep and superficial features of the triangle, lying centrally surrounded by ischioanal fat. The urogenital (UG) triangle is anterior to this line. In contrast to the open anal triangle, the UG triangle is “closed” by a thin sheet of tough, deep fascia, the perineal membrane, which stretches between the two sides of the pubic arch, covering the anterior part of the pelvic outlet The perineal membrane thus fills the anterior gap in the pelvic diaphragm (the urogenital hiatus, but is perforated by the urethra in both sexes and by the vagina of the female. The membrane and the ischiopubic rami to which it attaches provide a foundation for the erectile bodies of the external genitalia—the penis and scrotum of males and the pudendum or vulva of females— which are the superficial features of the triangle |
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What is perenial body |
Perenial body is an irregular mass, variable in size and consistency, and containing collagenous and elastic fibers, and both skeletal and smooth muscle The midpoint of the line joining the ischial tuberosities is the central point of the perineum. This is the location of the perineal body The perineal body lies deep to skin, with relatively little overlying subcutaneous tissue, posterior to the vestibule or bulb of the penis and anterior to the anus and anal canal. The perineal body is the site of convergence and interlacing of fibers of several muscles, including the: •Bulbospongiosus. •External anal sphincter. •Superficial and deep transverse perineal muscles . •Smooth and voluntary slips of muscle from the external urethral sphincter, levator ani, muscular coats of the rectum. Anteriorly, the perineal body blends with the posterior border of the perineal membrane superiorly with the rectovesical or rectovaginal septum |
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Describe perineal fasciae? |
The perineal fascia consists of superficial and deep layers. The subcutaneous tissue of the perineum, like that of the inferior anterior abdominal wall consists of a superficial fatty layer and a deep membranous layer, the (superficial) perineal fascia (Colles fascia). In females, the fatty layer of subcutaneous tissue of the perineum makes up the substance of the labia majora and mons pubis and is continuous anteriorly and superiorly with the fatty layer of subcutaneous tissue of the abdomen (Camper fascia) In males, the fatty layer is greatly diminished in the urogenital triangle, being replaced altogether in the penis and scrotum with smooth (dartos) muscle. It is continuous between the penis or scrotum and thighs with the fatty layer of subcutaneous tissue of the abdomen (Fig. 3.53B & D). In both sexes, the fatty layer of subcutaneous tissue of the perineum is continuous posteriorly with the ischioanal fat pad in the anal region (Fig. 3.53E). The membranous perineal fascia does not extend into the anal triangle, being attached posteriorly to the posterior margin of the perineal membrane and perineal body (Fig. 3.53A & B). Laterally it is attached to the fascia lata (deep fascia) of the superiormost medial aspect of the thigh (Fig. 3.53C & E). Anteriorly in males, the perineal fascia is continuous with the dartos fascia of the penis and scrotum; however, on each side of and anterior to the scrotum, the perineal fascia becomes continuous with the membranous layer of subcutaneous tissue of the abdomen (Scarpa fascia) In females, the perineal fascia passes superior to the fatty layer forming the labia majora and becomes continuous with the membranous layer of subcutaneous tissue of the abdomen (Fig. 3.53A & C). The deep perineal fascia (investing or Gallaudet fascia) intimately invests the ischiocavernosus, bulbospongiosus, and superficial transverse perineal muscles It is also attached laterally to the ischiopubic rami. Anteriorly it is fused to the suspensory ligament of the penis and is continuous with the deep fascia covering the external oblique muscle of the abdomen and the rectus sheath. In females, the deep perineal fascia is fused with the suspensory ligament of the clitoris and, as in males, with the deep fascia of the abdomen |
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Define superficial perineal pouch and enumerate its contents in both male and females |
The superficial perineal pouch (compartment) is a potential space between the perineal fascia and the perineal membrane, bounded laterally by the ischiopubic rami In males, the superficial perineal pouch contains the: • Root(bulb and crura) of the penis and associated muscles (ischiocavernosus and bulbospongiosus). •Proximal (bulbous) part of the spongy urethra. • Superficial transverse perineal muscles. • Deep perineal branches of the internal pudendal vessels and pudendal nerves. In females, the superficial perineal pouch contains the: • Clitoris and associated muscles (ischiocavernosus). • Bulbs of the vestibule and surrounding muscle (bulbospongiosus). • Greater vestibular glands. • Superficial transverse perineal muscles. Related vessels and nerves (deep perineal branches of the internal pudendal vessels and pudendal nerves). |
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Define deep perenial pouch and enumerate its contents |
The deep perineal pouch (space) is bounded inferiorly by the perineal membrane, superiorly by the inferior fascia of the pelvic diaphragm, and laterally by the inferior portion of the obturator fascia (covering the obturator internus muscle) (Fig. 3.53C & D). It includes the fat-filled anterior recesses of the ischioanal fossae. The superior boundary in the region of the urogenital hiatus is indistinct. In both sexes, the deep perineal pouch contains: •Part of the urethra, centrally. •The inferior part of the external urethrals phincter muscle, above the center of the perineal membrane, surrounding the urethra. •Anterior extensions of the ischi oanal fat pad |
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Contents of deep perenial pouch in the males |
In males, the deep perineal pouch contains the: • Intermediate part of the urethra, the narrowest part of the male urethra. • Deep transverse perineal muscles, immediately superior to the perineal membrane (on its superior surface), running transversely along its posterior aspect. • Bulbourethral glands, embedded within the deep perineal musculature. •Dorsal neurovascular structures of the penis. |
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Contents of the perineal pouch in females |
Proximal part of the urethra. •A mass of smooth muscle in the place of deep transverse perineal muscles on the posterior edge of the perineal membrane, associated with the perineal body. •Dorsal neurovasculature of the clit oris. |
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Ischioanal fossa |
The ischioanal fossae (formerly called ischiorectal fossae) on each side of the anal canal are
large fascia-lined, wedge shaped spaces between the skin of the anal region and the pelvic diaphragm
The apex of each fossa lies superiorly where the levator ani muscle arises from the obturator fascia.
The ischioanal fossae, wide inferiorly and narrow superiorly, are filled with fat and loose connective tissue.
The two ischioanal fossae communicate by means of the deep postanal space over the anococcygeal ligament (body), a fibrous mass located between the anal canal and the tip of the coccyx
Each ischioanal fossa is filled with a fat body of the ischioanal fossa. These fat bodies support the anal canal but they are readily displaced to permit descent and expansion of the anal canal during the passage of feces. The fat bodies are traversed by tough, fibrous bands, as well as by several neurovascular structures, including the inferior anal/rectal vessels and nerves and two other cutaneous nerves, the perforating branch of S2 and S3 and the perineal branch of S4 nerve. |
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What are the boundaries of Ischioanal fossa? |
Each ischioanal fossa is bounded:Laterally by the ischium and overlapping inferior part of the obturator internus, covered with obturator fascia. •Medially by the external anal sphincter, with a sloping superior medial wall or roof formed by the levator ani as it descends to blend with the sphincter; both structures surround the anal canal. Posteriorly by the sacrotuberous ligament and gluteus maximus. •Anteriorly by the bodies of the pubic bones, inferior to the origin of the puborectalis. These parts of the fossae, extending into the UG triangle superior to the perineal membrane (and musculature on its superior surface), are known as the anterior recesses of the ischioanal fossae. |
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Pudendal canal |
The pudendal canal(Alcock canal) is an essentially horizontal passageway within the obturator fascia that covers the medial aspect of the obturator internus and lines the lateral wall of the ischioanal fossa (Figs. 3.55A and 3.56). The internal pudendal artery and vein, the pudendal nerve, and the nerve to the obturator internus enter this canal at the lesser sciatic notch, inferior to the ischial spine. The internal pudendal vessels and the pudendal nerve supply and drain blood from and innervate most of the perineum. As the artery and nerve enter the canal, they give rise to the inferior rectal artery and nerve, which pass medially to supply the external anal sphincter and the perianal skin Toward the distal (anterior) end of the pudendal canal, the artery and nerve both bifurcate, giving rise to the perineal nerve and artery, which are distributed mostly to the superficial pouch (inferior to the perineal membrane), and to the dorsal artery and nerve of the penis or clitoris, which run in the deep pouch (superior to the membrane). When the latter structures reach the dorsum of the penis or clitoris, the nerves run distally on the lateral side of the continuation of the internal pudendal artery as they both proceed to the glans of the penis or glans of the clitoris. The perineal nerve has two branches: The superficial perineal nerve gives rise to posterior scrotal or labial (cutaneous) branches, and the deep perineal nerve supplies 1)the muscles of the deep and superficial perineal pouches, 2)the skin of the vestibule, 3) the mucosa of the inferiormost part of the vagina. The inferior rectal nerve communicates with the posterior scrotal or labial and perineal nerves. The dorsal nerve of the penis or clitoris is the primary sensory nerve serving the male or female organ, especially the sensitive glans at the distal end. |
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Anal canal |
The anal canal is the terminal part of the large intestine and of the entire digestive canal. It extends from the superior aspect of the pelvic diaphragm to the anus (Figs. 3.55B and 3.56). Origin The canal (2.5–3.5 cm long) begins where the rectal ampulla narrows at the level of the U-shaped sling formed by the puborectalis muscle (Fig. 3.12). Termination. The anal canal ends at the anus, the external outlet of the alimentary tract. Sphincters of Anal canal The anal canal, surrounded by internal and external anal sphincters, descends posteroinferiorly between the anococcygeal ligament and the perineal body. The canal is collapsed, except during passage of feces. Both sphincters must relax before defecation can occur.
Internal anal sphincter The internal anal sphincter is an involuntary sphincter surrounding the superior two thirds of the anal canal. It is a thickening of the circular muscle layer. Its contraction (tonus) is stimulated and maintained by sympathetic fibers from the superior rectal (periarterial) and hypogastric plexuses. Its contraction is inhibited by parasympathetic fiber stimulation, both intrinsically in relation to peristalsis and extrinsically by fibers passing through the pelvic splanchnic nerves. This sphincter is tonically contracted most of the time to prevent leakage of fluid or flatus; however, it relaxes (is inhibited) temporarily in response to distension of the rectal ampulla by feces or gas, requiring voluntary contraction of the puborectalis and external anal sphincter if defecation or flatulence is not to occur. The ampulla relaxes after initial distension (when peristalsis subsides) and tonus returns until the next peristalsis or until a threshold level of distension occurs, at which point inhibition of the sphincter is continuous until distension is relieved. External Anal sphincter The external anal sphincter is a large voluntary sphincter that forms a broad band on each side of the inferior two thirds of the anal canal This sphincter is attached anteriorly to the perineal body and posteriorly to the coccyx via the anococcygeal ligament. It blends superiorly with the puborectalis muscle. The external anal sphincter is described as having subcutaneous, superficial, deep parts; these are zones rather than muscle bellies and are often indistinct. The external anal sphincter is supplied mainly by S4 through the inferior rectal nerve although its deep part also receives fibers from the nerve to the levator ani, in common with the puborectalis, with which it contracts in unison to maintain continence when the internal sphincter is relaxed (except during defecation). The anal column and its content Internally, the superior half of the mucous membrane of the anal canal is characterized by a series of longitudinal ridges called anal columns These columns contain the terminal branches of the superior rectal artery and vein. The anorectal junction, indicated by the superior ends of the anal columns, is where the rectum joins the anal canal. At this point, the wide rectal ampulla abruptly narrows as it traverses the pelvic diaphragm. The inferior ends of the anal columns are joined by anal valves. Superior to the valves are small recesses called anal sinuses. When compressed by feces, the anal sinuses exude mucus, which aids in evacuation of feces from the anal canal. |
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Describe pectinate line and its importance |
The inferior comb-shaped limit of the anal valves forms an irregular line, the pectinate line, that indicates the junction of the superior part of the anal canal (visceral; derived from the embryonic hindgut), and the inferior part (somatic; derived from the embryonic proctodeum). The anal canal superior to the pectinate line differs from the part inferior to the pectinate line in its arterial supply, innervation, and venous and lymphatic drainage These differences result from the different embryological origins of the superior and inferior part of anal canal |
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Artrial and supply and venous drainage of anal canal |
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Innervation of Anal canal |
The nerve supply to the anal canal superior to the pectinate line is visceral innervation from the inferior hypogastric plexus,(mixed) involving sympathetic, parasympathetic, and visceral afferent fibers Sympathetic fibers maintain the tonus of the internal anal sphincter. Parasympathetic fibers inhibit the tonus of the internal sphincter and evoke peristaltic contraction for defecation. The superior part of the anal canal, like the rectum superior to it, is inferior to the pelvic pain line all visceral afferents travel with the parasympathetic fibers to spinal sensory ganglia S2–S4. Superior to the pectinate line, the anal canal is sensitive only to stretching, which evokes sensations at both the conscious and the unconscious (reflex) levels. For example, distension of the rectal ampulla inhibits (relaxes) the tonus of the internal sphincter. The nerve supply of the anal canal inferior to the pectinate line is somatic innervation derived from the inferior anal (rectal) nerves, branches of the pudendal nerve. Therefore, this part of the anal canal is sensitive to pain, touch, and temperature. Somatic efferent fibers stimulate contraction of the voluntary external anal sphincter. |
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Wha are the Contents of male urogenital triangle? |
Male genital organs(distal urethra scrotum and penis ) Perenial muscles 1)superficial transverse perenial muscles 2)Bulbospongiosus 3) ischiocavernosus |
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Distal male urethra |
The male urethra is subdivided into four parts: intramural (preprostatic), prostatic, intermediate, spongy. The intermediate (membranous) part of the urethra begins at the apex of the prostate and traverses the deep perineal pouch, surrounded by the external urethral sphincter. It then penetrates the perineal membrane, ending as the urethra enters the bulb of the penis Posterolateral to this part of the urethra are the small bulbourethral glands and their slender ducts, which open into the proximal part of the spongy urethra. The spongy urethra begins at the distal end of the intermediate part of the urethra and ends at the external urethral orifice, which is slightly narrower than any of the other parts of the urethra. The lumen of the spongy urethra is approximately 5 mm in diameter; however, it is expanded in the bulb of the penis to form the intrabulbar fossa and in the glans penis to form the navicular fossa. On each side, the slender ducts of the bulbourethral glands open into the proximal part of the spongy urethra; the orifices of these ducts are extremely small. There are also many minute openings of the ducts of mucus-secreting urethral glands into the spongy urethra. Arterial Supply of Distal Male Urethra. The arterial supply of the intermediate and spongy parts of the urethra is from branches of the dorsal artery of the penis Venous and Lymphatic Drainage of Distal Male Urethra. Veins accompany the arteries and have similar names. Lymphatic vessels from the intermediate part of the urethra drain mainly into the internal iliac lymph nodes whereas most vessels from the spongy urethra to the deep inguinal lymph nodes, but some lymph passes to the external iliac nodes. |
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Distal male urethra |
The male urethra is subdivided into four parts: intramural (preprostatic), prostatic, intermediate, spongy. The intermediate (membranous) part of the urethra begins at the apex of the prostate and traverses the deep perineal pouch, surrounded by the external urethral sphincter. It then penetrates the perineal membrane, ending as the urethra enters the bulb of the penis Posterolateral to this part of the urethra are the small bulbourethral glands and their slender ducts, which open into the proximal part of the spongy urethra. The spongy urethra begins at the distal end of the intermediate part of the urethra and ends at the external urethral orifice, which is slightly narrower than any of the other parts of the urethra. The lumen of the spongy urethra is approximately 5 mm in diameter; however, it is expanded in the bulb of the penis to form the intrabulbar fossa and in the glans penis to form the navicular fossa. On each side, the slender ducts of the bulbourethral glands open into the proximal part of the spongy urethra; the orifices of these ducts are extremely small. There are also many minute openings of the ducts of mucus-secreting urethral glands into the spongy urethra. Arterial Supply of Distal Male Urethra. The arterial supply of the intermediate and spongy parts of the urethra is from branches of the dorsal artery of the penis Venous and Lymphatic Drainage of Distal Male Urethra. Veins accompany the arteries and have similar names. Lymphatic vessels from the intermediate part of the urethra drain mainly into the internal iliac lymph nodes whereas most vessels from the spongy urethra to the deep inguinal lymph nodes, but some lymph passes to the external iliac nodes. |
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Discuss scrotum |
The scrotum is a cutaneous fibromuscular sac for the testes and associated structures. It is situated posteroinferior to the penis and inferior to the pubic symphysis. The bilateral embryonic formation of the scrotum is indicated by the midline scrotal raphe (Fig. 3.61A), which is continuous on the ventral surface of the penis with the penile raphe and posteriorly along the median line of the perineum with the perineal raphe. Internally, deep to the scrotal raphe, the scrotum is divided into two compartments, one for each testis, by a prolongation of the dartos fascia, the septum of the scrotum. The testes and epididymides and their coverings are present in scrotum Arterial Supply of Scrotum. Femoral arteries>external pudendal arteries>anterior scrotal artery Anterior scrotal arteries, terminal branches of the external pudendal arteries (from the femoral artery), supply the anterior aspect of the scrotum. Internal pudendal artrey> superficial perenial artrey>posterior scrotal artery Posterior scrotal arteries, terminal branches of the superficial perineal branches of the internal pudendal arteries, supply the posterior aspect (Fig. 3.58A; Table 3.8). The scrotum also receives branches from the cremasteric arteries (branches of the inferior epigastric arteries). Venous and Lymphatic Drainage of Scrotum. The scrotal veins accompany the arteries, sharing the same names but draining primarily to the external pudendal veins. Lymphatic vessels drain lymph into superficial inguinal lymph nodes |
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Innervation of scrotum |
The anterior aspect of the scrotum is supplied by derivatives of the lumbar plexus: anterior scrotal nerves, derived from the ilioinguinal nerve, and the genital branch of the genitofemoral nerve (Table 3.10). The posterior aspect of the scrotum is supplied by derivatives of the sacral plexus: posterior scrotal nerves, branches of the 1)superficial perineal branches of the pudendal nerve, 2) the perineal branch of the posterior cutaneous nerve of thigh Sympathetic fibers conveyed by these nerves assist in the thermoregulation of the testes, stimulating contraction of the smooth dartos muscle in response to cold or stimulating the scrotal sweat glands while inhibiting contraction of the dartos muscle in response to excessive warmth. |
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Anatomy of penis |
The penis is the male copulatory organ and, by conveying the urethra, provides the common outlet for urine and semen (Figs. 3.60–3.62). The penis consists of a root, body, and glans. It is composed of three cylindrical cavernous bodies of erectile tissue: the paired corpora cavernosa dorsally and the single corpus spongiosum ventrally. In the anatomical position, the penis is erect; when the penis is flaccid, its dorsum is directed anteriorly. Each cavernous body has an outer fibrous covering or capsule, the tunica albuginea (Fig. 3.61C). Superficial to the outer covering is the deep fascia of the penis (Buck fascia), the continuation of the deep perineal fascia that forms a strong membranous covering for the corpora cavernosa and corpus spongiosum, binding them together (Fig. 3.61C & D). The corpus spongiosum contains the spongy urethra. The corpora cavernosa are fused with each other in the median plane, except posteriorly where they separate to form the crura of the penis (Figs. 3.60 and 3.62B). Internally, the cavernous tissue of the corpora is separated (usually incompletely) by the septum penis (Fig. 3.61C). The root of the penis, the attached part, consists of the crura, bulb, and ischiocavernosus and bulbospongiosus muscles (Figs. 3.60 and 3.62A & B). The root is located in the superficial perineal pouch, between the perineal membrane superiorly and the deep perineal fascia inferiorly (see Fig. 3.53B & D). The crura and bulb of the penis consist of erectile tissue. Each crus is attached to the inferior part of the internal surface of the corresponding ischial ramus (see Fig. 3.52D), anterior to the ischial tuberosity. The enlarged posterior part of the bulb of the penis is penetrated superiorly by the urethra, continuing from its intermediate part (Figs. 3.60 and 3.62B). The body of the penis is the free pendulous part that is suspended from the pubic symphysis. Except for a few fibers of the bulbospongiosus near the root of the penis and the ischiocavernosus that embrace the crura, the body of the penis has no muscles (Fig. 3.62). The penis consists of thin skin, connective tissue, blood and lymphatic vessels, fascia, the corpora cavernosa, and corpus spongiosum containing the spongy urethra (Fig. 3.61C). Distally, the corpus spongiosum expands to form the conical glans of penis, or head of the penis (Figs. 3.61A, B, & D and 3.62B). The margin of the glans projects beyond the ends of the corpora cavernosa to form the corona of the glans. The corona overhangs an obliquely grooved constriction, the neck of the glans, which separates the glans from the body of the penis. The slit-like opening of the spongy urethra, the external urethral orifice (meatus), is near the tip of the glans. The skin of the penis is thin, darkly pigmented relative to adjacent skin, and connected to the tunica albuginea by loose connective tissue. At the neck of the glans, the skin and fascia of the penis are prolonged as a double layer of skin, the prepuce (foreskin), which in uncircumcised males covers the glans to a variable extent (Fig 3.61E). The frenulum of the prepuce is a median fold that passes from the deep layer of the prepuce to the urethral surface of the glans (Fig. 3.61A & D). |
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Ligaments of penis |
Suspensory Ligament The suspensory ligament of the penis is a condensation of deep fascia that arises from the anterior surface of the pubic symphysis (Fig. 3.63). The ligament passes inferiorly and splits to form a sling that is attached to the deep fascia of the penis at the junction of its root and body. The fibers of the suspensory ligament are short and taut, anchoring the erectile bodies of the penis to the pubic symphysis. Fundiform ligament The fundiform ligament of the penis is an irregular mass or condensation of collagen and elastic fibers of the subcutaneous tissue that descends in the midline from the linea alba anterior to the pubic symphysis The ligament splits to surround the penis and then unites and blends inferiorly with the dartos fascia forming the scrotal septum. The fibers of the fundiform ligament are relatively long and loose and lie superficial (anterior) to the suspensory ligament. |
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Arterial supply of penis |
The penis is supplied mainly by branches of the internal pudendal arteries Dorsal arteries of the penis run on each side of the deep dorsal vein in the dorsal groove between the corpora cavernosa supplying the fibrous tissue around the corpora cavernosa, the corpus spongiosum and spongy urethra, and the penile skin. • Deep arteries of the penis pierce the crura proximally and run distally near the center of the corpora cavernosa, supplying the erectile tissue in these structures • Arteries of the bulb of the penis supply the posterior (bulbous) part of the corpus spongiosum and the urethra within it as well as the bulbourethral gland In addition, superficial and deep branches of the external pudendal arteries supply the penile skin, anastomosing with branches of the internal pudendal arteries. The deep arteries of the penis are the main vessels supplying the cavernous spaces in the erectile tissue of the corpora cavernosa and are, therefore, involved in the erection of the penis. They give off numerous branches that open directly into the cavernous spaces. When the penis is flaccid, these arteries are coiled, restricting blood flow; they are called helicine arteries of the penis ( |
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Venous drainage of penis |
Blood from the cavernous spaces.(little chambers inside the corpora cavernosa) is drained by a venous plexus that joins the deep dorsal vein of the penis in the deep fascia (Figs. 3.61C and 3.63). This vein passes between the laminae of the suspensory ligament of the penis, inferior to the inferior pubic ligament and anterior to the perineal membrane, to enter the pelvis, where it drains into the prostatic venous plexus. Blood from the skin and subcutaneous tissue of the penis drains into the superficial dorsal vein(s), which drain(s) into the superf icial external pudendal vein. Some blood also passes to the internal pudendal vein. |
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Innervation of penis |
The nerves derive from the S2–S4 spinal cord segments and spinal ganglia, passing through the pelvic splanchnic gives branch called cavernous nerve and pudendal nerves, respectively (Fig. 3.64). Sensory and sympathetic innervation is provided primarily by the dorsal nerve of the penis, a terminal branch of the pudendal nerve, which arises in the pudendal canal and passes anteriorly into the deep perineal pouch. It then runs to the dorsum of the penis, where it runs lateral to the dorsal artery (Figs. 3.61C and 3.63). It supplies both the skin and glans penis. The penis is richly supplied with a variety of sensory nerve endings, especially the glans penis. |
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What is lymphatic drainge of male perinium |
Lymph from the skin of all parts of the perineum, including the hairless skin inferior to the pectinate line of the anorectum but excluding the glans penis, drains to the superficial inguinal nodes. . Reflective of their abdominal origins, lymph from the testes follow a route, independent of the scrotal drainage, along the testicular veins to the intermesenteric portion of the lumbar (caval/aortic) and preaortic lymph nodes. M Lymphatic drainage from the intermediate and proximal parts of the urethra and cavernous bodies drain into the internal iliac lymph nodes, whereas Nmost vessels from the distal spongy urethra and glans penis pass to the deep inguinal nodes, but some lymph passes to the external inguinal nodes. |
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What are the perenial muscles of male? |
The superficial perineal muscles, located in the superficial perineal pouch, include the 1)superficial transverse perineal, 2)bulbospongiosus, 3)ischiocavernosus muscles (Figs. 3.62A and 3.66).
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Superficial transverse perenial muscle |
The superficial transverse perineal muscles and the bulbospongiosus muscles join the external anal sphincter in attaching centrally to the perineal body. They cross the pelvic outlet like intersecting beams, supporting the perineal body to aid the pelvic diaphragm in supporting the pelvic viscera. Simultaneous contraction of the superficial perineal muscles (plus the deep transverse perineal muscle) during penile erection provides a firmer base for the penis. |
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Bulbospongiosus |
1) aids is in emptying of spongy urethra 2) erect penis by encircling the proximal parts of body of penis 3) provides enlargement and rigidity to penis by impeding dorsal veins of penis so that less blood is drained from the penis |
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Bulbospongiosus |
1) aids is in emptying of spongy urethra 2) erect penis by encircling the proximal parts of body of penis 3) provides enlargement and rigidity to penis by impeding dorsal veins of penis so that less blood is drained from the penis |
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Ischiocavernosus |
The ischiocavernosus muscles surround the crura in the root of the penis. They force blood from the cavernous spaces in the crura into the distal parts of the corpora cavernosa, which increases the turgidity (firm distension) of the penis during erection. Contraction of the ischiocavernosus muscles also compresses the tributaries of deep dorsal vein of the penis leaving the crus of the penis, thereby restricting venous outflow from the penis and helping maintain the erection. Because of their function during erection and the activity of the bulbospongiosus subsequent to urination and ejaculation to expel the last drops of urine and semen, the perineal muscles are generally more developed in males than in females. |
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Erection |
When a male is stimulated erotically,
arteriovenous anastomoses by which blood is normally able to bypass the “empty” potential spaces or sinuses of the corpora cavernosa are closed.
The smooth muscle in the fibrous trabeculae and coiled helicine arteries relaxes (is inhibited) as a result of parasympathetic stimulation (S2–S4 through the cavernous nerves from the prostatic nerve plexus). Consequently, the helicine arteries straighten, enlarging their lumina and allowing blood to flow into and dilate the cavernous spaces in the corpora of the penis.
The bulbospongiosus and ischiocavernosus muscles compress veins egressing from the corpora cavernosa, impeding the return of venous blood.
As a result, the corpora cavernosa and corpus spongiosum become engorged with blood near arterial pressure, causing the erectile bodies to become turgid (enlarged and rigid), and an erection occurs.
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How emission of semen occurs? |
During emission, semen (sperms and other glandular secretions) is delivered to the prostatic urethra through the ejaculatory ducts after peristalsis of the ductus deferentes and seminal glands.
Prostatic fluid is added to the seminal fluid as the smooth muscle in the prostate contracts.
Emission is a sympathetic response (L1–L2 |
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Ejaculation |
During ejaculation, semen is expelled from the urethra through the external urethral orifice. Ejaculation results from: •Closure of the internal urethral sphincter at the neck of the urinary bladder, a sympathetic response (L1–L2 nerves). •Contraction of the urethral muscle, a parasympathetic response (S2–S4 nerves). •Contraction of the bulbospongiosus muscles, from the pudendal nerves (S2–S4) parasympathetic response
REEMISSION (penile flacididty) After ejaculation, the penis gradually returns to a flaccid state (remission), resulting from sympathetic stimulation, which causes constriction of the smooth muscle in the coiled helicine arteries. The bulbospongiosus and ischiocavernosus muscles relax, allowing more blood to be drained from the cavernous spaces in the penile corpora into the deep dorsal vein. |
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Female external Genetilia |
The female external genitalia include the mons pubis, labia majora (enclosing the pudendal cleft), labia minora (enclosing the vestibule of vagina), clitoris, Vestibule bulbs of vestibule, greater and lesser vestibular glands. The synonymous terms vulva and pudendum include all these parts; the term pudendum is commonly used clinically. The vulva serves: •As sensory and erectile tissue forse xual arousal and intercourse. •To direct the flow of urine. •To prevent entry of foreign material into the urogenital tract Mons Pubis. The mons pubis is the rounded, fatty eminence anterior to the pubic symphysis, pubic tubercles, and superior pubic rami. The eminence is formed by a mass of fatty subcutaneous tissue The amount of fat increases at puberty and decreases after menopause. The surface of the mons is continuous with the anterior abdominal wall. After puberty, the mons pubis is covered with coarse pubic hairs. Labia Majora The labia majora are prominent folds of skin that indirectly protect the clitoris and urethral and vaginal orifices (Fig. 3.67). Each labium majus is largely filled with a finger-like “digital process” of loose subcutaneous tissue containing smooth muscle and the termination of the round ligament of the uterus (Fig. 3.68A). It passes inferoposteriorly from the mons pubis toward the anus (Fig. 3.67B–D). The labia majora lie on the sides of a central depression (a narrow slit when the thighs are adducted—Fig. 3.67A), the pudendal cleft, within which are the labia minora and vestibule (Fig. 3.67B–D). The external aspects of the labia majora in the adult are covered with pigmented skin containing many sebaceous glands and are covered with crisp pubic hair. The internal aspects of the labia are smooth, pink, and hairless. The labia majora are thicker anteriorly where they join to form the anterior commissure. Posteriorly, in nulliparous women (those never having borne children) they merge to form a ridge, the posterior commissure, which overlies the perineal body and is the posterior limit of the vulva. This commissure usually disappears after the first vaginal birth. Labia Minora The labia minora are rounded folds of fat-free, hairless skin. They are enclosed in the pudendal cleft and immediately surround and close over the vestibule of vagina into which both the external urethral and the vaginal orifices open. They have a core of spongy connective tissue containing erectile tissue at their base and many small blood vessels. Anteriorly, the labia minora form two laminae. The medial laminae of each side unite as the frenulum of the clitoris. The lateral laminae unite anterior to (or often anterior and inferior to, thus overlapping and obscuring) the glans of the clitoris, forming the prepuce (foreskin) of the clitoris. In young women, especially virgins, the labia minora are connected posteriorly by a small transverse fold, the frenulum of the labia minora (fourchette). Although the internal surface of each labium minus consists of thin moist skin, it has the pink color typical of mucous membrane and contains many sebaceous glands and sensory nerve endings. Clitoris The clitoris is an erectile organ located where the labia minora meet anteriorly (Figs. 3.67 and 3.68). The clitoris consists of a root and a small, cylindrical body, which are composed of two crura, two corpora cavernosa, and the glans of the clitoris (Fig. 3.69). The crura attach to the inferior pubic rami and perineal membrane, deep to the labia. The body of the clitoris is covered by the prepuce (Figs. 3.67 and 3.68). Together, the body and glans of the clitoris are approximately 2 cm in length and <1 cm in diameter. In contrast to the penis, the clitoris is not functionally related to the urethra or to urination. It functions solely as an organ of sexual arousal. Labia MajoraThe labia majora are prominent folds of skin that indirectly protect the clitoris and urethral and vaginal orifices (Fig. 3.67). Each labium majus is largely filled with a finger-like “digital process” of loose subcutaneous tissue containing smooth muscle and the termination of the round ligament of the uterus (Fig. 3.68A). It passes inferoposteriorly from the mons pubis toward the anus (Fig. 3.67B–D).The labia majora lie on the sides of a central depression (a narrow slit when the thighs are adducted—Fig. 3.67A), the pudendal cleft, within which are the labia minora and vestibule (Fig. 3.67B–D). The external aspects of the labia majora in the adult are covered with pigmented skin containing many sebaceous glands and are covered with crisp pubic hair. The internal aspects of the labia are smooth, pink, and hairless. The labia majora are thicker anteriorly where they join to form the anterior commissure. Posteriorly, in nulliparous women (those never having borne children) they merge to form a ridge, the posterior commissure, which overlies the perineal body and is the posterior limit of the vulva. This commissure usually disappears after the first vaginal birth. Labia Minora The labia minora are rounded folds of fat-free, hairless skin. They are enclosed in the pudendal cleft and immediately surround and close over the vestibule of vagina into which both the external urethral and the vaginal orifices open. They have a core of spongy connective tissue containing erectile tissue at their base and many small blood vessels. Anteriorly, the labia minora form two laminae. The medial laminae of each side unite as the frenulum of the clitoris. The lateral laminae unite anterior to (or often anterior and inferior to, thus overlapping and obscuring) the glans of the clitoris, forming the prepuce (foreskin) of the clitoris. In young women, especially virgins, the labia minora are connected posteriorly by a small transverse fold, the frenulum of the labia minora (fourchette). Although the internal surface of each labium minus consists of thin moist skin, it has the pink color typical of mucous membrane and contains many sebaceous glands and sensory nerve endings. Clitoris The clitoris is an erectile organ located where the labia minora meet anteriorly (Figs. 3.67 and 3.68). The clitoris consists of a root and a small, cylindrical body, which are composed of two crura, two corpora cavernosa, and the glans of the clitoris (Fig. 3.69). The crura attach to the inferior pubic rami and perineal membrane, deep to the labia. The body of the clitoris is covered by the prepuce (Figs. 3.67 and 3.68). Together, the body and glans of the clitoris are approximately 2 cm in length and <1 cm in diameter. In contrast to the penis, the clitoris is not functionally related to the urethra or to urination. It functions solely as an organ of sexual arousal. The clitoris is highly sensitive and enlarges on tactile stimulation. The glans of the clitoris is the most highly innervated part of the clitoris and is densely supplied with sensory endings. Vestibule The vestibule is the space surrounded by the labia minora into which the orifices of the urethra and vagina and the ducts of the greater and lesser vestibular glands open (Figs. 3.67C & D and 3.68A). Texternal urethral orifice is located 2–3 cm posteroinferior to the glans of the clitoris and anterior to the vaginal orifice. On each side of the external urethral orifice are the openings of the ducts of the paraurethral glands (Fig. 3.68A). Openings of the ducts of the greater vestibular glands are located on the upper, medial aspects of the labia minora, in 5 and 7 o’clock positions relative to the vaginal orifice in the lithotomy position. The size and appearance of the vaginal orifice vary with the condition of the hymen, a thin anular fold of mucus membrane, which partially or wholly occludes the vaginal orif ice. After its rupture, only remnants of the hymen, hymenal caruncles(tags), are visible (Fig. 3.67C & D). These remnants demarcate the vagina from the vestibule. The hymen has no established physiological function. It is considered primarily a developmental vestige, but its condition (and that of the frenulum of the labia minora) often provides critical evidence in cases of child abuse and rape. BUlbs of vestibuleThe bulbs of the vestibule are paired masses of elongated erectile tissue, approximately 3 cm in length (Fig. 3.68A & B). The bulbs lie along the sides of the vaginal orifice, superior or deep to (not within) the labia minora, immediately inferior to the perineal membrane . They are covered inferiorly and laterally by the bulbospongiosus muscles extending along their length. The bulbs are homologous with the bulb of the penis. Vistibular Glands The greater vestibular glands (Bartholin glands), approximately 0.5 cm in diameter, are located in the superficial perineal pouch. They lie on each side of the vestibule, posterolateral to the vaginal orifice and inferior to the perineal membrane; thus they are in the superficial perineal pouch (Fig. 3.68B). The greater vestibular glands are round or oval and are partly overlapped posteriorly by the bulbs of the vestibule. Like the bulbs, they are partially surrounded by the bulbospongiosus muscles. The slender ducts of these glands pass deep to the bulbs of the vestibule and open into the vestibule on each side of the vaginal orifice. These glands secrete mucus into the vestibule during sexual arousal. The lesser vestibular glands are small glands on each side of the vestibule of vagina that open into it between the urethral and the vaginal orifices. These glands secrete mucus into the vestibule, which moistens the labia and vestibule. The labia majora are prominent folds of skin that indirectly protect the clitoris and urethral and vaginal orifices (Fig. 3.67). Each labium majus is largely filled with a finger-like “digital process” of loose subcutaneous tissue containing smooth muscle and the termination of the round ligament of the uterus (Fig. 3.68A). It passes inferoposteriorly from the mons pubis toward the anus (Fig. 3.67B–D).The labia majora lie on the sides of a central depression (a narrow slit when the thighs are adducted—Fig. 3.67A), the pudendal cleft, within which are the labia minora and vestibule (Fig. 3.67B–D). The external aspects of the labia majora in the adult are covered with pigmented skin containing many sebaceous glands and are covered with crisp pubic hair. The internal aspects of the labia are smooth, pink, and hairless. The labia majora are thicker anteriorly where they join to form the anterior commissure. Posteriorly, in nulliparous women (those never having borne children) they merge to form a ridge, the posterior commissure, which overlies the perineal body and is the posterior limit of the vulva. This commissure usually disappears after the first vaginal birth. Labia Minora The labia minora are rounded folds of fat-free, hairless skin. They are enclosed in the pudendal cleft and immediately surround and close over the vestibule of vagina into which both the external urethral and the vaginal orifices open. They have a core of spongy connective tissue containing erectile tissue at their base and many small blood vessels. Anteriorly, the labia minora form two laminae. The medial laminae of each side unite as the frenulum of the clitoris. The lateral laminae unite anterior to (or often anterior and inferior to, thus overlapping and obscuring) the glans of the clitoris, forming the prepuce (foreskin) of the clitoris. In young women, especially virgins, the labia minora are connected posteriorly by a small transverse fold, the frenulum of the labia minora (fourchette). Although the internal surface of each labium minus consists of thin moist skin, it has the pink color typical of mucous membrane and contains many sebaceous glands and sensory nerve endings. Clitoris The clitoris is an erectile organ located where the labia minora meet anteriorly (Figs. 3.67 and 3.68). The clitoris consists of a root and a small, cylindrical body, which are composed of two crura, two corpora cavernosa, and the glans of the clitoris (Fig. 3.69). The crura attach to the inferior pubic rami and perineal membrane, deep to the labia. The body of the clitoris is covered by the prepuce (Figs. 3.67 and 3.68). Together, the body and glans of the clitoris are approximately 2 cm in length and <1 cm in diameter. In contrast to the penis, the clitoris is not functionally related to the urethra or to urination. It functions solely as an organ of sexual arousal. The clitoris is highly sensitive and enlarges on tactile stimulation. The glans of the clitoris is the most highly innervated part of the clitoris and is densely supplied with sensory endings. Vestibule The vestibule is the space surrounded by the labia minora into which the orifices of the urethra and vagina and the ducts of the greater and lesser vestibular glands open (Figs. 3.67C & D and 3.68A). Texternal urethral orifice is located 2–3 cm posteroinferior to the glans of the clitoris and anterior to the vaginal orifice. On each side of the external urethral orifice are the openings of the ducts of the paraurethral glands (Fig. 3.68A). Openings of the ducts of the greater vestibular glands are located on the upper, medial aspects of the labia minora, in 5 and 7 o’clock positions relative to the vaginal orifice in the lithotomy position. The size and appearance of the vaginal orifice vary with the condition of the hymen, a thin anular fold of mucus membrane, which partially or wholly occludes the vaginal orif ice. After its rupture, only remnants of the hymen, hymenal caruncles(tags), are visible (Fig. 3.67C & D). These remnants demarcate the vagina from the vestibule. The hymen has no established physiological function. It is considered primarily a developmental vestige, but its condition (and that of the frenulum of the labia minora) often provides critical evidence in cases of child abuse and rape. BUlbs of vestibuleThe bulbs of the vestibule are paired masses of elongated erectile tissue, approximately 3 cm in length (Fig. 3.68A & B). The bulbs lie along the sides of the vaginal orifice, superior or deep to (not within) the labia minora, immediately inferior to the perineal membrane . They are covered inferiorly and laterally by the bulbospongiosus muscles extending along their length. The bulbs are homologous with the bulb of the penis. Vistibular Glands The greater vestibular glands (Bartholin glands), approximately 0.5 cm in diameter, are located in the superficial perineal pouch. They lie on each side of the vestibule, posterolateral to the vaginal orifice and inferior to the perineal membrane; thus they are in the superficial perineal pouch (Fig. 3.68B). The greater vestibular glands are round or oval and are partly overlapped posteriorly by the bulbs of the vestibule. Like the bulbs, they are partially surrounded by the bulbospongiosus muscles. The slender ducts of these glands pass deep to the bulbs of the vestibule and open into the vestibule on each side of the vaginal orifice. These glands secrete mucus into the vestibule during sexual arousal. The lesser vestibular glands are small glands on each side of the vestibule of vagina that open into it between the urethral and the vaginal orifices. These glands secrete mucus into the vestibule, which moistens the labia and vestibule. The clitoris is highly sensitive and enlarges on tactile stimulation. The glans of the clitoris is the most highly innervated part of the clitoris and is densely supplied with sensory endings. Vestibule The vestibule is the space surrounded by the labia minora into which the orifices of the urethra and vagina and the ducts of the greater and lesser vestibular glands open (Figs. 3.67C & D and 3.68A). Texternal urethral orifice is located 2–3 cm posteroinferior to the glans of the clitoris and anterior to the vaginal orifice. On each side of the external urethral orifice are the openings of the ducts of the paraurethral glands (Fig. 3.68A). Openings of the ducts of the greater vestibular glands are located on the upper, medial aspects of the labia minora, in 5 and 7 o’clock positions relative to the vaginal orifice in the lithotomy position. The size and appearance of the vaginal orifice vary with the condition of the hymen, a thin anular fold of mucus membrane, which partially or wholly occludes the vaginal orif ice. After its rupture, only remnants of the hymen, hymenal caruncles(tags), are visible (Fig. 3.67C & D). These remnants demarcate the vagina from the vestibule. The hymen has no established physiological function. It is considered primarily a developmental vestige, but its condition (and that of the frenulum of the labia minora) often provides critical evidence in cases of child abuse and rape. BUlbs of vestibule The bulbs of the vestibule are paired masses of elongated erectile tissue, approximately 3 cm in length (Fig. 3.68A & B). The bulbs lie along the sides of the vaginal orifice, superior or deep to (not within) the labia minora, immediately inferior to the perineal membrane . They are covered inferiorly and laterally by the bulbospongiosus muscles extending along their length. The bulbs are homologous with the bulb of the penis. Vistibular Glands The greater vestibular glands (Bartholin glands), approximately 0.5 cm in diameter, are located in the superficial perineal pouch. They lie on each side of the vestibule, posterolateral to the vaginal orifice and inferior to the perineal membrane; thus they are in the superficial perineal pouch (Fig. 3.68B). The greater vestibular glands are round or oval and are partly overlapped posteriorly by the bulbs of the vestibule. Like the bulbs, they are partially surrounded by the bulbospongiosus muscles. The slender ducts of these glands pass deep to the bulbs of the vestibule and open into the vestibule on each side of the vaginal orifice. These glands secrete mucus into the vestibule during sexual arousal. The lesser vestibular glands are small glands on each side of the vestibule of vagina that open into it between the urethral and the vaginal orifices. These glands secrete mucus into the vestibule, which moistens the labia and vestibule. |
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Arterial supply and venous drainage of external genitalia of female (vulva) |
The abundant arterial supply to the vulva is from the external and internal pudendal arteries (Fig. 3.68A; see also Fig. 3.58B; Table 3.8). The internal pudendal artery supplies most of the skin, external genitalia, and perineal muscles. The labial arteries are branches of the internal pudendal artery, as are those of the clitoris. The labial veins are tributaries of the internal pudendal veins and accompanying veins of the internal pudendal artery. Venous engorgement during the excitement phase of the sexual response causes an increase in the size and consistency of the clitoris and the bulbs of the vestibule of the vagina. |
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Innervation of vulva |
The anterior aspect of the vulva (mons pubis, anterior labia) is supplied by derivatives of the lumbar plexus: the anterior labial nerves, derived from the ilioinguinal nerve, and the genital branch of the genitofemoral nerve. The posterior aspect of the vulva is supplied by derivatives of the sacral plexus: the perineal branch of the posterior cutaneous nerve of the thigh laterally and the pudendal nerve centrally (Fig. 3.70). The latter is the primary nerve of the perineum. Its posterior labial nerves (terminal superficial branches of the perineal nerve) supply the labia. Deep and muscular branches of the perineal nerve supply the orifice of the vagina and superficial perineal muscles. The dorsal nerve of the clitoris supplies deep perineal muscles and sensation to the clitoris. The bulb of the vestibule and erectile bodies of the clitoris receive parasympathetic fibers via cavernous nerves from the uterovaginal nerve plexus. Parasympathetic stimulation produces increased vaginal secretion, erection of the clitoris, and engorgement of erectile tissue in the bulbs of the vestibule. |
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Contents of female urogenital triangle |
It includes Female external genetalia Perneneal muscles Anal canal |
