Pelvis Notes

Front 1

Muscles in floor of pelvis

Back 1

Levator ani
Coccygeus muscle
Superficial transverse perineal muscle
Deep transverse perineal muscle
Sphincter urethrae
External anal sphincter
Bulbospongiosus muscle
Ischiocaveronus muscle

Front 2

Muscles in pelvic diaphragm and their origin:

Back 2

Levatores ani muscles originates on the posterior side of the body of pubis, the tendinous arch, ischial spine.
Coccygeus muscles - ischial spine

Front 3

Groups of the levatores ani muscles

Back 3

Anterior fibers: Levator prostatae or sphincter vaginae - form sling around the prostatae or vaginae and are inserted to the perineal body.
Intermediate fibers:
1. Puborectalis forms sling around junction of rectum and anal canal
2. Pubococcygeus goes to the annococcygeal body between coccyx and anal canal
Posterior fibers: The iliococcygeus runs to the annococcygeal body and coccyx

Front 4

Innervation of the levator ani muscle:

Back 4

Sacral plexus

Front 5

Blood supply of the levator ani:

Back 5

Branches of the internal pudendal artery and inferior vescical artery

Front 6

Levator ani muscles from medial to lateral:

Back 6

Puborectalis is most medially, then pubcoccygeus. Iliococcygeus is most lateral.

Front 7

Coccygeus muscle - origin and insertion

Back 7

From ischial spine to lower end of sacrum and coccyx.

Front 8

External anal sphincter muscle

Back 8

supplements pelvic diaphragm. Is divided into three parts:
1. Subcutaneous part: Encircles lower end of anal canal, no bony attachments.
2. Superficial part - attached to coccyx and perineal body
3. Deep part - encircles upper part of anal canal and has no bony attachments. It blends with puborectalis fibers.

Front 9

Boundaries of perineum

Back 9

Anteriorly: Pubic symphysis
Posteriorly: Tip of coccyx
Laterally: Inferior pubic and ischial rami, ischial tuberosities, sacrotuberous ligaments.

Front 10

Boundaries of anal triangle:

Back 10

Posteriorly: Tip of coccyx
Each side: Ischial tuberosity, sacrotuberous ligament, overlapped by gluteus maximus.

Front 11

Relations of anal canal

Back 11

Posteriorly: Anococcygeal body.
Laterally: Ischiorectal fossae.
Anteriorly:
In the male - perineal body, urogenital diaphragm, membranous part of urethra, bulb of penis
In the female - perineal body, urogenital diaphragm, lower part of vagina.

Front 12

Boundaries of ischiorectal fossa

Back 12

Wedge-shaped space on each side of the anal canal.
Base of wedge: Skin
Medial wall: Sloping levator ani muscle and anal canal
Lateral wall: Lower part of obturator internus muscle

Front 13

Contents of ischiorectal fossa:

Back 13

Dense fat supporting anal canal.
On the lateral wall of fossa there's the pudendal canal, which embeds the pudendal nerve, internal pudendal vessels and perineal nerve.
The inferior rectal vessels and nerve cross the fossa to reach the anus.

Front 14

Fascia and muscles of urogenital DIAPHRAGM

Back 14

Formed by the sphincter urethrae and deep transverse perineal muscle. The superficial transverse perineal muscle supplements it. It's covered by superior fascia and inferior fascia (perineal membrane).
Anteriorly the superior fascia joins with inferior fascia forming the TRANSVERSE LIGAMENT of perineum. The dorsal penis or clitoris vessels run in the fissure between the arcuate ligament of pubis and transverse ligament.

Front 15

Blood supply and innervation of the urogenital diaphragm

Back 15

Branches of internal pudendal vessels and pudendal nerve

Front 16

The testis is invested by three coats:

Back 16

Tunica vaginalis
Tunica albuginea
Tunica vasculosa

Front 17

Tunica vaginalis (male)

Back 17

Lower end of the peritoneal processus vaginalis. The visceral layer covers the whole testis except for most of the posterior aspect. Posteromedially it's reflected forward to the parietal layer.
Posterolaterally it passes to the medial aspect of the epididymis, lining the epididymal sinus, where it's reflected forward to become continuous with the parietal layer.

Front 18

Mesorchium

Back 18

Where the visceral layer goes into the parietal layer of tunica vaginalis

Front 19

Tunica albuginea (male)

Back 19

Covers testis, is covered externally by visceral layer of tunica vaginalis except at the epididymal head and tail and the posterior aspect of the testis where vessels and nerves enter.

Front 20

Mediastinum testis

Back 20

Incomplete septum of tunica albuginea at the posterior border of the testis. Septula testis radiate from the mediastinum into the testicular interior.

Front 21

Tunica vasculosa

Back 21

Contains plexus of blood vessels and loose connective tissue. Extends over internal aspect of tunica albuginea and covers septa and all the testicular lobules.

Front 22

Internal architecture of the testis

Back 22

Lobules of testis (200-300)
Each lobule contains 1-3 convoluted seminiferous tubules which look like anastomotic loops, and which open into tubuli recti and then into rete testis.

Front 23

Layers of cross-section through scrotum and testis

Back 23

Skin of scrotum
Superficial (dartos) fascia
External spermatic fascia
Cremaster muscle and fascia
Internal spermatic fascia
Parietal layer of tunica vaginalis
Visceral layer of tunica vaginalis
Tunica albuginea of testis
Lobules, septa, rete testis.

Front 24

Drainage duct of testes

Back 24

Ductus deferens (vas deferens)

Front 25

Lymph drainage of the testes

Back 25

Lateral aortic or lumbar nodes and pre-aortic nodes in abdomen.

Front 26

Interstitial cells (Leydig cells)

Back 26

Adjacent to the seminiferous tubules in the testicle. They produce testosterone.

Front 27

Sertoli cells

Back 27

Found in the testis. They help in the process of turning stem cells into sperm. It's part of the seminiferous tubules.

Front 28

Parts of epididymis

Back 28

It's made up of a head, body and tail. It stretches from the back of the testicle to the vas deferens. The head is connected to the upper pole of the testis by efferent ductules, which form lobules of epididymis.

Front 29

Blood supply of the testis and epididymis

Back 29

Testicular artery from abdominal aorta
Testicular veins form pampiniform plexus. This plexus is reduced to a single vein as it ascends through the inguinal canal.
The right testicular vein - IVC
The left - left renal vein

Front 30

True epididymis

Back 30

Body and tail of epididymis. The true epididymis is distinguished from the efferent ductules, which form a coiled mass known as the head of the epididymis.

Front 31

Contents of the inguinal canal

Back 31

Genital branch of the genitofemoral nerve
Spermatic cord/round ligament of uterus
Ilio-inguinal nerve passes through parts of it, exiting through the superficial inguinal ring

Front 32

Anterior wall of inguinal canal

Back 32

Aponeurosis of the external oblique muscle. Reinforced laterally by the internal oblique.

Front 33

Posterior wall of inguinal canal

Back 33

Transversalis fascia.
Reinforced along median 1/3 by conjoint tendon.

Front 34

Roof of inguinal canal

Back 34

Transversus abdominis and internal oblique muscles

Front 35

Floor of inguinal canal:

Back 35

Inguinal ligament

Front 36

Structures in the spermatic cord

Back 36

Ductus deferens
Artery to ductus deferens
Testicular artery
Pampiniform plexus
Cremasteric artery and vein
Genital branch of the genitofemoral nerve
Sympathetic and visceral afferent nerve fibers
lymphatics
remnants of the processus vaginalis

Front 37

Fascias enclosing contents of spermatic cord

Back 37

Internal spermatic fascia is the deepest layer, and it arises from the transversalis fascia.
Cremasteric fascia with cremasteric muscle, which is middle layer and arises from the internal oblique muscle
External spermatic fascia, which is most superficial and arises from aponeurosis of the external oblique.

Front 38

Course of ductus deferens

Back 38

From tail of epididymis to ejaculatory duct. Ascends in spermatic cord, passes through inguinal canal, bends medially around the inferior epigastric artery. Crosses external iliac vessels at pelvic inlet to enter pelvic cavity.
It descends deep to the peritoneum, crosses ureter posterior to the bladder. Continues along base of bladder. Almost at midline it's joined by the duct of the seminal vesicle to form the ejaculatory duct.

Front 39

Ampulla of ductus deferens is located

Back 39

between ureter and ejaculatory duct

Front 40

Location of seminal vesicle

Back 40

Immediately lateral to and follows the course of the ductus deferens at the base of the bladder

Front 41

Ureters in abdomen, from - to

Back 41

Ureters are continuous superiorly with renal pelvis. The ureters enter pelvic cavity anterior to the bifurcation of common iliac artery.

Front 42

Constrictions of ureter and clinical importance

Back 42

1. Uteropelvic junction (renal pelvis)
2. Pelvic inlet/brim where ureters cross common iliac vessels
3. Where ureters enter wall of the bladder.
Kidney stones can get lodged there.

Front 43

Course of ureters in pelvis

Back 43

They enter pelvic cavity anterior to bifurcation of common iliac artery. They go medially to:
External, internal iliac arteries,
umbilical and obturator arteries,
suspensory ligament (which contains ovarian vessels). It then goes laterally to the uterus, crosses UNDER the uterine artery and goes forward to the bladder.

Front 44

Contents of broad ligament

Back 44

Uterine tubes
(ovaries are sometimes considered to be ON and not IN broad lig)
Uterine artery
Round ligament

Front 45

Kidney structure

Back 45

Outer renal cortex, inner medulla. Extensions of renal cortex are renal columns. The columns divide medulla into renal pyramids.
The apex of the pyramids = Renal papilla. The papillas are surrounded by minor calyces. Minor calyces unite to form a major calyx. Two or three major calyces unite to form renal pelvis, which is the end of the ureter.

Front 46

Position of bladder

Back 46

Apex: Towards pubic symphysis. Median umbilical ligament continues from it superiorly, to the umbilicus.
Base: 2 ureters enter at the upper corners of the base, the urethra drains from lower corner of the base.
Inferolateral surfaces of the bladder are cradled between levator ani and obturator internus muscles.
The neck of the bladder is the most inferior part of the bladder.

Front 47

Position of prostate related to bladder

Back 47

The fibrous capsule of the prostate surrounds the neck of the bladder and adjacent part of the urethra.

Front 48

The bladder is supported by:

Back 48

the pubovesical ligaments, the perineal membrane and associated muscles, the levator ani muscles and the pubic bones.

Front 49

How is neck of bladder anchored in women?

Back 49

In women, the neck of bladder is anchored by the pubovesical ligaments, which connect the neck and pelvic part of the urethra to the pubic bones.

Front 50

How is the neck of bladder anchored in men?

Back 50

puboprostatic ligaments, which blend with the fibrous capsule to the prostate, which surrounds the neck of the bladder and adjacent part of urethra.

Front 51

Layers of scrotum corresponding to layers in abdomen

Back 51

Skin - skin
Superficial (dartos) fascia - Fatty layer
External spermatic fascia - External oblique
Cremasteric fascia - internal oblique
internal spermatic fascia - fascia transversalis
Tunica vaginalis - peritoneum.