W01: Reproductive Anatomy - Pelvis & Perineum

Question 1

Major Landmarks of the Bony Pelvis

Answer 1

• Sacrum (posterior)
• ASIS
• Ischial Tuberosities (sitting down)
• Ischial Spines
• Obturator Foramen: occluded by muscle

Question 2

What joint type is the sacroiliac joint?

Answer 2

synovial diarthroid
* synovial plane: non axial

Question 3

What joint type is the pubic symphysis?

Answer 3

secondary cartilaginous joint

Question 4

Bones of the pelvis

Answer 4

ILIUM

PUBIS (anterior)

ISCHIUM (inferior)

Question 5

What organs are associated with the iliac fossae?

Answer 5

Caecum, appendix (RIGHT)

Sigmoid colon (LEFT)

Question 6

Arcuate Line

Answer 6

Divides false pelvis and the true pelvis

Question 7

Differences between male and female pelvis

Answer 7

Male = Narrower pelvis
Female = Wider

Male = Narrow sub-pubic angle very acute but very wide and obtuse in females

Inlets:
* Male = heart shaped
* Female = oval rounded

Question 8

Pelvicc Walls and roof

Answer 8

1. OBTURATOR INTERNUS: lateral wall, true pelvis, obturator foramen = obturator canal
2. PIRIFORMIS: posteiror superior wall; from the middle sacrum, passes out of the greater sciatic foramen

= both exit to join hip joint and become lateral rotators

3. COCCYGEUS: posterior-inferior of the pelvic floor

Question 9

What muscle ligament exits the lesser scitatic foramen?

Answer 9

The obturator internus’ ligament

exits out of the pelvis via the lesser sciatic foramen

Question 10

Pelvic Floor

Answer 10

LEVATOR ANI:
1. PUBOCOCCYGEUS

2. ILIOCOCCYGEUS
3. PUBORECTALIS

+ Arcuate Tendon

+ Perineal body
+ Anococcygeal body

Question 11

Significance of the puborectalis muscle

Answer 11

Wraps around the pernieal flexure of the rectum and vital in faecal continence

= creates a kink in the tract and relaxes/ flexes

Question 12

What is the narrowest diameter of the pelvic inlet

Answer 12

antero-posteiror diameter

Question 13

What is the narrowest diameter of the pelvic outlet?

Answer 13

transverse intraspinous diameter

Question 14

Muscles of the pelvicwall cavity

Answer 14

OBTURATOR FASCIA: antero-lateral; look for obturator canal

piriformis: posterior wall of pelcis

coccygeus

Question 15

Pelvic Floor

Answer 15

POST
- coccygeus
- iliococcygeus
- pubococcygeus
- puborectalis
ANT

Question 16

Two functions of the pelvic diaphragm

Answer 16

• support abdominopelvic viscera
• resistance to increased intrapelvic pressure
• continence

Question 17

What is a cystocele

Answer 17

Weakening of tissue of bladder and vaginal wall => collapse into cagina

Question 18

Rectocele

Answer 18

Prolapse where supportive wall between rectum and vaginal wall

Question 19

At what vertebral level does the common iliac artery divide into internal and external?

Answer 19

L5-S1

Question 20

Obturator Art.

Answer 20

travels along obturator canal w/ obturator vein and nerve

• supplies the adductor region
• origin: internal iliac

Question 21

Umbilliac Art.

Answer 21

=> superior vesical artery

• supplies the superior urinary bladder

Question 22

Inferior Vescical Art

Answer 22

supplies lower bladder, prostate, seminal vesicle

Question 23

Uterine Art

Answer 23

travels within cardinal ligament (lateral cervical ligament)

• crosses ureters during course

Question 24

Middle Rectal Art

Answer 24

supplies the distal rectum

Question 25

Internal Pudendal Art

Answer 25

Mainly supplies the perineum

Question 26

Inferior Gluteal Art.

Answer 26

Terminal branch of the internal iliac artery

Question 27

Significance of the Gonadal Arteries

Answer 27

RESPECTIVELY, THE OVARIAN AND TESTICULAR ARTERIES supply ovaries and testicles and arise from the ABDOMINAL AORTA just inferior to insertion of renal arteries into the kidneys * testicular artery travels via inguinal canal via deep inguinal ring

Question 28

Which part of the rectum drains into the portal circulation?

Answer 28

superior rectal vein => inferior mesenteric vein

Question 29

Which part of the rectum drains into the systemic circulation?

Answer 29

Inferior and middle veins

Question 30

Significance of the communications of the prostatic venous plexus?

Answer 30

Communicates with vertebral venous plexus thus significant for mets spread

Question 31

ilioinguinal nerve

Answer 31

originates L1 superficial inguinal ring => skin root penus, labia

Question 32

genitofemoral nerve

Answer 32

L1-2 deep inguinal ring > scrotal skin, cromaster muscle

Question 33

Pudendal nerve

Answer 33

arises form sacral plexus (S2-S4) * follows pudendal artery * pudendal canal (also known as Alcock’s canal – a structure formed by the fascia of the obturator internus muscle) > skin and muscles of perineum > Motor – innervates various pelvic muscles, the external urethral sphincter and the external anal sphincter.

Question 34

divisions of the pudendal nerve

Answer 34

giving off the inferior rectal nerve, then the perineal nerve, before continuing as the dorsal nerve of the penis or clitoris.

Question 35

Perineal Nerve

Answer 35

(pudendal) innervates bulbospongious, ischiocavernous, levator ani, innervates the external urethral sphincter Therefore, the pudendal nerve provides the voluntary/somatic control of faecal and urinary continence.

Question 36

Sensory innervation of external genitalia

Answer 36

Inferior rectal nerve – the perianal skin ,lower third of the anal canal. Perineal nerve – the skin of the perineum, labia minora and majora or posterior scrotum. Dorsal nerve of the penis or clitoris – the skin of the penis or clitoris. Thus, responsible for the afferent component of penile and clitoral erection.

Question 37

Bony landmark significant for pudendal nerve block

Answer 37

ischial spine

Question 38

autonomic nerve supply of pelvis

Answer 38

pelvic plexus sympathetic = L1, L2 = hypogastric nerve and terminal aspect of symp. trunk parasymp = pelvic splanchnic nerves (S2 - S4) erectile tissues

Question 39

What is damaged in rectal surgeyr resulting in dysfunctional ejaculation in men?

Answer 39

Autonomic sympathetic nervous system (hypogastirc nerve)

Question 40

Lymphatic drainage of pelvis

Answer 40

EXT. ILIAC LN = > ANTEROSUPERIOR PELVIC INTERNAL ILIAC LN > gluteal region, deep perineum, inferior pelvic viscera SACRAL LN > postero. viscera LUMBAR LN > drainage from three main groups