Pelvis and Perineum 1.3

Question 1

What does the pudendal nerve and its branches innervate (M)?

Answer 1

skin and skeletal muscles of the male perineum

Question 2

Where does the pudendal nerve arise from? (M)

Answer 2

anterior rami of S2, S3, and S4 spinal cord levels

Question 3

After emerging from the pudendal (Alcock’s) canal what does the pudendal nerve divides into? (M)

Answer 3

• inferior anal (rectal) nerves
  1. the perineal nerve
  2. superficial and deep branches of the perineal nerve (which also supply the scrotum)
  3. the dorsal nerve of the penis.

Question 4

Where do paraysmpathetic fibers arise (M)?

Answer 4

S2-S4 levels

Question 5

How do the parasympathetic fibers travel (M)?

Answer 5

in pelvic splanchnic nerves to the inferior hypogastric plexus and prostatic nerve plexus

Question 6

What do parasympathetic fibers stimualte?

Answer 6

1. release of nitric oxide from the nerve endings and endothelial cells of the erectile tissues
2. which relaxes smooth muscle tone and increases blood flow to permit erection

Question 7

What is erectile dysfunction?

Answer 7

inability to achieve or maintain penile erection sufficient for sexual intercourse

Question 8

What does nitric oxide released by the pelvic splanchnic parasympathetic nerve fibers and endothelial cells normally cause?

Answer 8

• dilation of the arteries supplying blood to the erectile tissues
• when this mechanism is compromised, ed results

Question 9

How do drugs targeting ed work?

Answer 9

aid smooth muscle relaxation by augmenting the action of nitric oxide

Question 10

What is the primary blood supply for the pelvic viscera and perineum (W)?

Answer 10

internal iliac artery

Question 11

How does the internal iliac artery divide (W)?

Answer 11

1. anterior trunk (which largely supplies pelvic viscera and the perineum)
2. posterior trunk

Question 12

What do the branches of the posterior trunk supply (W)?

Answer 12

pelvic walls or pass through the greater sciatic foramen into the gluteal region

Question 13

Does the branching pattern of the internal iliac artery vary? (W)

Answer 13

greatly, so it is advisable to name the arteries according to the structures that they supply

Question 14

Where do the veins drain? (W)

Answer 14

• Veins draining the corresponding structures are similarly identified and named
• drain into the internal iliac vein and into the common iliac vein on each side and then into the inferior vena cava

Question 15

How do cancer cells originating in the pelvic viscera metastasise? (W)

Answer 15

• via the venous system and will generally follow the venous drainage back toward the central venous circulation
• most of the pelvic viscera this means via the inferior vena cava, although some spread to the adjacent veins of the vertebral column is also common

Question 16

What is the internal pudendal artery (W)?

Answer 16

branch of the anterior division of the internal iliac artery

Question 17

What is the course of the internal pudendal artery (W)?

Answer 17

courses to the perineum by passing through the lesser sciatic foramen and the pudendal (Alcock’s) canal

Question 18

What does the internal pudendal artery give off (W)?

Answer 18

• the inferior rectal artery

- the perineal artery

Question 19

What do branches of the perineal artery supply? (W)

Answer 19

• bulb of the vestibule
• crus of the clitoris
• clitoris

Question 20

What accompanies all the branches of the internal pudendal artery? (W)

Answer 20

• Venous branches

- names correspond to the names of the arterial branches

Question 21

Where does the lymphatic network of the perineum drain? (W)

Answer 21

1. largely to the superficial inguinal lymph nodes
2. then along the iliac nodes to the paraaortic (lumbar) nodes in the abdomen
3. Infections and cancer cells travelling in the lymphatic follow this same pathway

Question 22

What are the 3 sets of veins draining blood from the rectum and anal canal?

Answer 22

1. Inferior rectal veins from the internal pudendal vein (caval system)
2. Middle rectal veins from the internal iliac vein (caval system)
3. Superior rectal vein from the inferior mesenteric vein (portal system).

Question 23

What do these valveless veins provide?

Answer 23

important portacaval anastomosis around the rectum should the venous return by the portal or caval system be impeded

Question 24

Where is there a lot of anastomoses?

Answer 24

between the venous tributaries in the walls of the anal canal and rectum, corresponding arteries accompany these veins

Question 25

What is hemorrhoids?

Answer 25

symptomatic varicose dilations of submucosal veins that protrude into the anal canal or extend through the anus

Question 26

How common is hemorrhoids?

Answer 26

affect 50% to 80% of individuals (more common after pregnancy)

Question 27

What are the different types of hemorrhoids?

Answer 27

1. internal hemorrhoids (dilations of veins of internal rectal plexus)
2. external hemorrhoids (dilations of veins of external rectal plexus)
3. mixed (combination of both)

Question 28

What does the internal iliac artery supply? (M)

Answer 28

pelvic structures, perineum, and external genitalia

Question 29

Within the spermatic cord what does the pampiniform venous plexus surround? (M)

Answer 29

the testicular artery and drains blood from the testes into the testicular vein

Question 30

What does the pampiniform venous plexus act as? (M)

Answer 30

a countercurrent cooling mechanism that cools the arterial blood flowing in the testicular artery

Question 31

When does spermatogenesis occur? (M)

Answer 31

only if the temperature is lower than body temperature

Question 32

Where do the testes reside? (M)

Answer 32

• in the scrotum a

- possess this countercurrent mechanism to maintain the appropriate ambient temperature

Question 33

How common is prostatic carcinoma?

Answer 33

most common visceral cancer in men and the second leading cause of death in men over 50 years of age, after lung cancer

Question 34

Why does prostatic carcinoma metastsise?

Answer 34

• Pelvic lymphatics

- rich prostatic venous plexus drainage facilitate the metastatic spread to distant sites

Question 35

What does the prostatic artery supply (M)?

Answer 35

the prostate gland

Question 36

What is the prostatic artery a branch of? (M)

Answer 36

nferior vesical artery (the artery to the urinary bladder)

Question 37

Is there variability in the arteries to the pelvic viscera? (M)

Answer 37

significant variability in the arteries to the pelvic viscera can exist, and the arteries often form small anastomotic connection

Question 38

What are extensive venous plexuses associated with? (M)

Answer 38

bladder, rectum, and prostate in the male

Question 39

Why is there common cancer cell metastases? (M)

Answer 39

1. prostate’s close apposition to adjacent viscera
2. its rich prostatic venous plexus and lymphatic system provide pathways for direct-invasion, lymphatic, and/or blood-borne cancer cell metastases to adjacent viscera (bladder, urethra, seminal vesicle, rectum), the bony pelvic walls, the spine, and distant sites

Question 40

What is the internal pudendal artery a branch of? (M)

Answer 40

anterior division of the internal iliac artery

Question 41

How does the internal pudendal artery enter the perineum? (M)

Answer 41

• by passing out of the gluteal region
• through the lesser sciatic foramen
• coursing through the pudendal (Alcock’s) canal

Question 42

What does the internal pudendal artery give rise to? (M)

Answer 42

1. inferior rectal artery

2. perineal artery

Question 43

What do branches of the perineal artery supply? (M)

Answer 43

1. bulb of the penis
2. corpus cavernosum
3. the penis
4. the scrotum

Question 44

What accompanies the branches of the internal pudendal artery? (M)

Answer 44

• Venous tributaries

- names of these veins correspond to the names of the arterial branches

Question 45

What can extravasation of urine from a rupture of the spongy urethra spread into? (M)

Answer 45

1. the superficial pouch of the urogenital triangle
2. into the scrotum beneath the dartos fascia
3. around the penis between the dartos and deep penile (Buck’s) fascia
4. and into the lower abdominal wall beneath the membranous (Scarpa’s) fascia

Question 46

In women how does the peritoneoum pass from the anterior abdominal wall? (W)

Answer 46

over the superior surface of the urinary bladder

Question 47

What does the peritoneum then form and pass over? (W)

Answer 47

passes from the bladder to the uterus, forming the vesicouterine pouch between these 2 structures

Question 48

What does the peritoneum continue over?

Answer 48

1. over the fundus
2. body of the uterus
3. posterior fornix
4. wall of the vagina

Question 49

How does the peritoneum reflect?

Answer 49

onto the anterior and lateral sides of the rectum

Question 50

What is between the rectum and uterus?

Answer 50

rectouterine pouch

Question 51

Posteriorly and superiorly what does the peritoneum become?

Answer 51

the sigmoid mesocolon

Question 52

What is in the suspensory ligament of the ovary?

Answer 52

ovarian vessels, nerves, and lymphatics

Question 53

How does the round ligament of the uterus travel?

Answer 53

passes anteriorly and laterally to the deep, or internal, inguinal ring

Question 54

What does the broad ligament of the uterus provide?

Answer 54

1. Support to uterus

2. With pelvic diaphragm and cardinal and uterosacral ligament helps keeps uterus from prolapsing