Anatomy Of Pelvis And Perineum

Front 1

Bony pelvis

Back 1

Hip bones, sacrum and coccyx

Front 2

Types of pelvis

Back 2

Gynecoid, android, anthropoid, and plateploid

Front 3

The difference b/n male and female pelvis

Back 3

In female

1. Bone : thinner, lighter, and shorter

2. Pubic arch or subpubic angle : wider ( obtuse)

3. Obtrutor foramen: oval in female and heart shape in male

4. Sacrum: shorter and wider and more curved

5. Ischial spines projects less

Front 4

Joints and ligaments of pelvis

Back 4

1. Sacroiliac joint ( anterior and posterior) and supported by posterior, interossous and anterior sacroiliac ligaments. The interossous sacroiliac ligament is the strongest ligament between the sacrum and ilium.

2. Sacrococcygeal joint : supported posteriorly by broad ligamentous band is known as sacroiliac ligament.

3. Symphysis pubis joint

4. Lumbosacral joint

Front 5

The courses of sacrospinous ligament

Back 5

Originate from the sacrum and insert into ischial spine and forms the lower boarder of greater sciatic foramen. It also forms the roof of lesser sciatic foramen

Front 6

The function of the greater and lesser foramen

Back 6

Allows the emergence of muscles, nerves and arteries from the pelvis to the gluteal region and the entrance of veins from the gluteal region to pelvis.

Front 7

The two ligaments add stability to the sacroiliac joints are

Back 7

1. Sacrospinous ligament

2. Sacrotuberous ligament

Front 8

Ligaments that support pelvic joints are

Back 8

1. Ilolumbar

2. Sacroiliac (3)

3. Sacrococcygeal (deep and superficial)

4. Pubis symphysis

5. Others : arcuate pubic ligament

Sacrospinous ligament

Sacrotuberous ligament

Front 9

Categorize the pelvic joints under synovial and fibrocartilagious

Back 9

The iliosacral is synovial, the rest 3 joints are fibrocartilagious

Front 10

Mention all pelvic viscera of female pelvis

Back 10

1. GIT. Rectum and anus

2. Reproductive: vagina, uterus, uterine tube and ovaries

3. Urinary: pelvic part of ureter, bladder

1. The ovaries in posterolateral aspect of the true pelvis

Held in position by peritoneal ligamentous attachments: broad ligament, round ligament, ovary ligament and suspensory ligament ( transmit the ovarian vessels and ovarian autonomic nerves), so that it is called band

2. The uterus is positioned between the bladder and the rectum and forms two pouches ( vesicouterine and rectouterine pouches).

3. The uterine tube ( classified as uterine opening , isthmus, ampullae, lnfundibulem, and fimbrae).

Front 11

Match the following

Back 11

1. Fimbrae. A. Uterus

2. Ampulla. B. Cervix

3. Uterus. C. Out side of uterus

4. Ectopic. D. Implantation

5. Anteverted. E. Fertilization

6. Anteflexed. F. Collect ova

7.

Front 12

Genital organs of the adult female include

Back 12

1. Ovary

2. Uterine tube

3. Uterus

4. Vagina

5. Glands and external genital organs

Front 13

Match the followings

Back 13

1. Mullerian duct. A. Ovary or testicles

2. Gonads. B. Gubernaculum

3. Developing

ligament of ovary. C. Uterine tube

4. Sulpinx. D. Rectouterine pouch

5. Intramural. E. Intrauterine

6. Douglass. F. Isthmus of uterine tube

Front 14

What will happen on the position of uterus if a mother is pregnant?

Back 14

Retroverted, retroflexed position

Front 15

What are the two peritoneal pouches between the bladder and uterus, and between the rectus and uterus? Which pouch extends to vaginal forinx?

Back 15

1. Vesicouterine and rectouterine pouches.

2. Rectouterine pouch

Front 16

The attachments of the uterus include:

Back 16

1. Broad ligament that attach to the lateral margin of the uterus

2. Round ligaments and ovarian ligaments that the uterus just below the uterine tube.

3. Uterosacral ligaments that attach the uterus to sacral

4. Cardinal ligaments that attach the uterus and vagina laterally.

Front 17

What arteries are supplying female pelvic genital organs?

Back 17

1. Uterine arteries from the internal iliac and branches right and left vaginal arteries, and right and left tubal and ovarian branch of uterine arteries.

2. Ovarian arteries that stem from aorta

3. The vaginal arteries usually from uterine artery branch but they may branch from the inferior vesical artery or directly from internal iliac artery.

The uterine artery anastomosis with the arterial supply of the vagina and also anastomosis with ovarian arteries freely along the lateral boarder of the uterus.

4. Medial rectal artery

5. Superior rectal artery from inferior mesenteric continuation

6. Superior vesical artery

7. Inferior vesical artery

Front 18

Variation in arterial supply to the ovary

Back 18

1. 56% of cases blood to the ovary comes from both the ovarian and uterine arteries

2. In 40% from the ovarian arteries only

3. In 4% from the uterine arteries only.

Front 19

Discuss the Variation of arterial supply of the fundus of the uterus

Back 19

1. In 90% from the uterine artery

2. Where as , in 10% it comes from the ovarian artery.

Front 20

Discuss the variation of the internal iliac artery supply

Back 20

1. In 10 % the internal iliac artery itself gives of all branches

2. In 60% the internal iliac artery divided into two main trunk: anterior (3) and posterior (8)

3. In 20 % the internal iliac artery divided into 3 branches

4. In 10% the internal iliac artery divides into more than 3 branches

Front 21

The obtrutor artery arises from

Back 21

1. Internal iliac artery: 70%

2. Inferior epigastric artery : 27 %

Front 22

The superior rectal artery derived from

Back 22

From the inferior mesenteric artery.

Front 23

Muscle of the pelvis that forms the pelvic diaphragm:

Back 23

☆ Pelvic diaphragm

1. Levator ani

2. Coccygeal muscle

Function:

• assist in supporting pelvic viscera by partially closing off the pelvic out let.

•maintaining urine and fecal continence

• helps and guides during child birth

• increases intra abdomen pressure during urination, defication, vomiting, and parturition.

☆ pelvic wall

3. Obtrutor internus

4. Piriformis

C. Pelvic fascia : connective tissue that fills or lines spaces around viscera and between the parietal peritoneum of the abdominal cavity and the muscular walls and floor of the pelvic cavity.

1. Visceral pelvic fascia: lines the pelvic viscera and is continuous with partial fascia where the organs pass through the pelvic hiatuses- urogenital and rectal.

2. Parietal pelvic fascia

This layer lines the muscles of the pelvic walls and floor internally.

3. Endopelvic fascia: occupies spaces around the pelvic viscera. ( either loose areolar connective tissue or dense fibrous tissue - often referred to as ligaments

Function: to support android protect pelvic viscera while allowing for distension of viscera. Two of the most important ligaments formed by emdopelvic fascia are the paired transverse cervical or cardinal and uterosacral ligaments in the female pelvis. Additional supportive structures include the lateral ligaments of the bladder and rectum.

D. Clinical significance

POP ( pelvic organs prolapse)

Pop is due to loose or weakening of pelvic floor muscles and ligamentous support and has significant negative impact on quality of life.

Dx: bowel, urinary and sexual dysfunction are indications for Rt, such as conservative methods : pelvic floor physical therapy, and the use of pessary, or surgical methods : reconstruction, organ removal, or surgical mesh-implantation.

POp: in females described as

cystocel is herniation of the bladder

(Rectocele),rectum , uterus prolapse to the level of vaginal walls of inferior. In cystocel and rectocele, anterior and posterior vaginal segments are herniated along with viscera, respectively. Enterocele involves herniation of intestines through the wall of the vagina.

Front 24

The uterus is supposed in position by:

Back 24

1. Its attachment to the bladder and rectum

2. The transverse cervical and uterosacral ligaments

3. The musculature that forms the pelvic floor and urogenital diaphragm.

Front 25

Perineum, pouches and contents

Back 25

Perineum is the structure below the pelvic diaphragm

It has deep perineal and superficial pouches.

Deep perineal pouches contains deep transverse perineal muscle and external urethral sphincter muscle

Superficial perineal pouch contains

Superficial perineal muscle

Bulbospongiosus

Ischiocavernosus

1. Deep transverse perineal muscle (female ) inferior ramus of the ischium to the side of the vagina and innervated by S2-S4

Action: helps fix the perineal body and assists the urethrovaginal sphincter

and urethral sphincter in male.

In male , inferior ramus of the ischium to tendinous raphe and innervated by S2-S4

Action:

2. Urethrovaginal sphincter: inferior fibers: from transverse perineal ligament to both sides of urethra ( pudendal nerve S2-4)

Action, helps fix the perineal body and assist the urethral sphincter.

Superior fibers: from the inner surface of pubic ramus to lower ends of urethra ( S2-4) .

Action, voluntary constrictor of vagina and urethra.

3. Sphincter of the urethra ( male)

Superficial part: from the transverse perineal ligament membranous urethra and perineal bodies(S2-4)

Action: voluntary construction of membranous urethra.

Deep part : from ramus of the pubis

Front 26

Perineum

Back 26

Shape: Diamond shaped region

Location: the pelvic diaphragm

Divided into: UGT and AT by IT line

Separated from pelvis by the muscular pelvic diaphragm.

Front 27

Boundaries of the perineum

Back 27

Anteriorly: symphysis pubis

Posteriorly: sacrum

Laterally: ischial tuberosities

The line between the ischial tuberosities divides the perineum into an anterior urogenital region and a posterior anal region

Two triangles share a common boundary represented by an imaginary line drawn between the right and left ischial tuberosities.

A. UGT: bounded by I-P rami, pubic symphysis and an imaginary line.

B. AT; coccyx, S.I ligament, and imaginary line.

Front 28

The urogenital triangle and anal triangle contains

Back 28

UGT contains

The external genitalia:

° labia majora, hair covered fatty layer

° minora is medial and deep to labia majora and also frame the vestibule.

° clitoris consists body and glans

° vestibule of the vagina is located between the labia minora and contains the external urethral orifice, and vaginal orifice. Para urethral,lessor vestibular, and greater vestibular glands open into this space.

♧ Female external genitalia collectively make up the vulva

* the perineal muscles, such as is

° iscocavernosus covers the crust of the clitoris

° bulbospongiosus which covers the vestibular bulbs.

♧ These muscles function to keep blood in the erectile tissues and maintain clitoral erection.

Bulbospongiosus also compresses the greater vestibular gland and attaches at the perineal body , there by strengthening the structure, and lubrication

Male structures of UGT:

Scrotum and penis

♧ the major difference in the male UGT is lack of a midline cleft which is evident by a scrotal and penile raphe

1. Scrotum is made up of cutaneous and fascial layers. The superficial perineal fascia is deep to the skin and is the peritoneal continuation of the superficial fascia of the abdomen.. with in the fascia, lays a layer of smooth muscle- dartos muscle which functions primary when the scrotum is exposed to cold temperatures wrinkling the scrotum and cremaster muscle which pulls scrotum to abdomen during cold.

The scrotum also contains a portion of spermatic cord and the testes.

2. Penis is formed by paired corpora cavernosa and in paired corpora spongiosum.

Paired corpora cavernosa in the penile shaft separate in to the right and left crura, which anchor the penis to the ischiopubic rami. The corpora spongiosum expands proximally into the bulb of the penis ( base) , which anchors the penis to the perineal membrane. It expand dismally in the glans penis, which is covered by double layer of the skin, prepuce ( fore skin). The penis is supported by facial layers , including the tunica albuginea around each cylinder and the deep fascia of the penis around all three cylinders. Neurovascular bundles travel between fascia layers

Male perineal muscles

1. Iscocavernosus

2. Bulbospongiosus which covers the crura and bulbs respectively.

♧ these muscles function to blood in the erectile tissues and maintain clitoral erection. Bulbospongiosus also compresses the bulb of the penis to expel urine , and ejaculate and attaches at the perineal body, there by strengthening the structures.

Superficial transverse perineal muscle course across the posterior boarder of the UGT, also inserting into and supporting the perineal body.

3. Perineal vasculature

A. Arterial supply:

• internal pudendal artery

Course: internal iliac artery >>inferior rectal artery >> perineal arteries >> labia/ scrotum and bulb of the vestibule/penis >> deep and dorsal arteries of the clitoris/penis.

B. Venous drainage

Occurs partially through external and internal pudendal veins.

♧ the deep arteries of the clitoris/penis give off helicine arteries within respective cavernosa bodies.

At rest ( remission) , these arteries are coiled and relaxed. With sexual arousal , helicine arteries dilate and straighten to allow increased arterial blood flow into the cavernous spaces, there by producing erection of the penis in males and clitoral swelling in females. The process is under parasympathetic control.

C. Lymphatic

Through either superficial inguinal or internal iliac lymph nodes.

D. Innervation

1. Somatic innervation of pudendal nerve S2 - S4. The course is like internal pudendal vessels

2. Autonomic innovation: autonomic sympathetic fibers primary distribute with branches of the pudendal nerves.

Pelvic splanchic nerves (S2-S4) contribute to the vesicle/ prostate plexus , which gives rise to cavernosa nerves

These parasympathetic nerves distribute to micro vasculature of erectile bodies ( clitoris/penis) and are responsible for erection/engorgement of the clitoris/penis.

♧ erection is under parasympathetic control, while emission ( delivery of semen) or ejaculation is under sympathetic control.

Male ejaculation involves additional coordination of somatic motor fibers to the bulbospongiosus muscle.

* glands, and membranes and anteriorly, there is small gap ( hiatus ) for passage of nerves and vessels of clitoris.

The anal region is posterior to urogenital region; it contains the anus surrounded by the external anal sphincter muscle. The large portion of anal region is occupied by the two fat filled ischiorectal fossae.

A. Membranes

Spans the width of the urogenital triangle serving as the superior and inferior boundaries of the superficial and deep perineal pouches, respectively. Surrounding muscle contracts to maintain erection by limiting venous drainage in both sex.

1. Superficial compartment; contains ischiocavernosus, bulbocavernosus, and superficial transverse perineal muscles, vessels and nerves.

2. The deep perineal compartment: is the space enclosed between the two layers of urogenital diaphragm. It contains the deep transverse perineal and urethral sphincter muscles and is transverse by the urethra and the vagina in females.

Perineal pouches

1. Superficial perineal pouch or space is suspended from a broad sheet of fascia.

Front 29

Discuss the course of pudendal structures ( vessels, and nerves) reach the perineum

Back 29

By way of pudendal canal( alcock) deep to the fascia of the internal muscle.

The vessels and nerves leave through the greater sciatic foramen along the lower boarder of the piriformis muscle and cross the ischial spine to reenter the pelvis through the lessor schiatic foramen. Their branches , the Inferior rectal vess6and nerves supply levator ani and the external anal sphincter muscles and other structures in the anal region. The pudendal nerves and vessels then continue anteriorly as the perineal vessels and nerves and enter the urogenital region by penetrating the urogenital diaphragm. They branch again superficial and deep branches to supply the superficial and deep compartments.

The superficial branch supply

Labia majora and the external genital structure, where as the deep branches supply the muscles, vestibules, bilbo and clitoris.

Front 30

Anal triangle

Back 30

1. Boundaries

A. Sacrotuberous ligament bilaterally

B. Coccyx posteriorly

C. Imaginary isciotubirous line anteriorly

2. Contains anal canal and anus , iscioanal fossae bilaterally

3. Development:

The upper anal canal from hind gut, where as lower anal canal from proctodeum, which is invagination of surface ectoderm caused by proliferation of mesoderm surrounding the anal membrane.

♧ the junction between the upper and lower anal canal is divided by the pectinate line in the adult.

Anatomy : is the distal 4cm of the GIT. It is continous with the rectum at the anorectal junction and extends to the anus. The upper anal canal is anal columns which are connected inferiorly by anal valves. The inferior boarder of the valves forms the pectinate line and demarcate upper from the lower anal canals

A

Muscles: the anal canal supported by both smooth and skeletal sphincters.

The internal, involuntary anal sphincter surrounds the upper anal canal and extends inferiorly to lie medial to the external ( voluntary) anal sphincter.

The external anal sphincter has three parts; deep,superficial and subcutaneous and contributes to the formation of the perineal body

Clinical significance

Hemorrhoids

Is the physical presentation of varicosites in the venous plexus of the anal canal. The cause is porta canal anastomosis in these regions are vulnerable to injury with disease processes such as portal hypertension.

In the anal canal, hemorrhoids are classified as either external or internal based on their origin, superior or inferior to the pectinate line, respectively.

Internal hemorrhoids are varicosites of superior rectal veins. The mucosa in this region does not have pain receptors, so these hemorrhoids are painless

External hemorrhoids are varicosites of inferior rectal veins. The skin in this region does possess pain receptors, making these type of hemorrhoid painful for the patient.

Blood supply

The upper anal canal supplied by the superior rectal artery from mesenteric artery ( abdominal aorta)

Venous drainage occurs through the rectal plexus into superior rectal vein of the portal system.

The lower anal canal is supplied by inferior rectal arteries from internal pudendal artery ( internal iliac)

Venous drainage occurs through inferior rectal veins, ultimately draining into caval system.

Innervation

The upper anal canal receive autonomic fiber through the rectal plexus

The lower anal canal structures receive somatic innervation from the inferior rectal nerves, branching of the pudendal nerve.

Fecal continence involves the coordination of both internal and external anal sphincters muscle.

Sympathetic stipulation causes tonic contraction of internal anal sphincter, while parasympathetic stimulation causes relaxation.

Clinical significance

Abscess with in perineal and parietal regions can extend through the external anal sphincter into the iscioanal fossae.

This common infection may arise due to a blocked anal crept gland

To avoid spreading abscess should be incised and drained

Anatomical fistula may develop as a result of a long standing abscess. Males more likely to develop an abscess and fistula in this region, compared to females.

Front 31

The pelvic outlet is closed by

Back 31

Musculofascial pelvic diaphragm.