8.3 Vessels, nerves & lymphatics of the Pelvis

Question 1

What is the main blood supply for the pelvis?

Answer 1

Internal iliac artery

Question 2

What are some smaller arteries that supply the pelvis?

Answer 2

Ovarian arteries, testicular arteries, superior rectal artery, medical sacral artery

Question 3

What level does the abdominal aorta divide into the common iliac branches?

Answer 3

L4-L5

Question 4

What are the two branches of the Internal iliac artery?

Answer 4

Posterior and Anterior branch

Question 5

Where does the posterior internal iliac artery branch to?

Answer 5

Branches to the body wall

Question 6

Where does the anterior internal iliac artery branch to?

Answer 6

Branches to the body wall and to the viscera

Question 7

What are the posterior internal iliac artery branches?

Answer 7

Iliolumbar, Lateral sacral and Superior gluteal

Question 8

What are the anterior internal iliac artery branches?

Answer 8

Obturator, Inferior gluteal and Internal pudendal

Question 9

What are the visceral branches of the Internal iliac artery?

Answer 9

Superior vesical (to bladder), Middle rectal, Uterine and Vaginal arteries

Question 10

What do the Uterine and Vagina arteries have to do with each other?

Answer 10

They anastomoses together

Question 11

How does the superior mesenteric vein drain?

Answer 11

It drains to the portal system via the inferior mesenteric vein

Question 12

Where does the internal iliac vein drain to?

Answer 12

It drains into the IVC

Question 13

Name the large visceral venous plexuses

Answer 13

Vesical, Prostatic, Uterovaginal, Rectal

Question 14

Do the venous plexuses of the pelvis have valves?

Answer 14

No, meaning blood can flow either direction

Question 15

What is different with the Prostatic venous plexus?

Answer 15

Normally drains to the IVC, has a retrograde drainage of the prostate via valveless veins to the vertebral canal via anterior sacral veins

Question 16

What can spread through the path venous blood takes through the body from the prostatic venous plexus?

Answer 16

Cancer can spread through the vertebral canal after moving from the prostate

Question 17

What veins are involved with a porto-systemic anastomoses in the pelvis?

Answer 17

Super rectal vein (portal) with middle and inferior rectal veins (systemic)

Question 18

What might happen with an elevation in portal venous pressure?

Answer 18

May result in distension of thin walled communicating veins at sites of portal systemic anastomoses

Question 19

What direction does lymph flow?

Answer 19

Superficial to Deep

Question 20

Where does lymph from the pelvic viscera drain?

Answer 20

Drains to deep lymph nodes

Question 21

Where does lymph from the skin of the perineum drain to?

Answer 21

Drains to inguinal nodes then to superficial lymph nodes

Question 22

What 2 places do lymph from pelvic viscera drain to?

Answer 22

Nodes along iliac vessels and para-aortic nodes

Question 23

Where does lymph from the testes drain to?

Answer 23

It drains to para aortic nodes on the posterior abdominal wall

Question 24

Where does lymph from the scrotum drain to?

Answer 24

It drains to inguinal nodes

Question 25

What is a problem with the lymph in the pelvis?

Answer 25

That they are situated deeply and cant be palpable. One man only learn about cancer when it reaches the clavicular nodes

Question 26

What supplies muscles of the pelvis?

Answer 26

Sacral plexus (S2-4)

Question 27

What are the main branches of the sacral plexus?

Answer 27

Obturator and Pudendal nerves

Question 28

What does the Pudendal nerve innervate?

Answer 28

The Perineum and external genitalia

Question 29

What is unusual about the positioning of the Pudendal nerve?

Answer 29

It supplies all its branches from below to allow for no compression

Question 30

What are 3 nerve areas of visceral nerves in the Pelvis?

Answer 30

Superior hypogastric plexus- Sympathetic (T11-L1), Inferior hypogastric plexus- Mixed sym/para, Pelvic splanchnic nerves (S2-4)

Question 31

What supplies the rectum and anal canal?

Answer 31

Above the pectineal line the supply is from the superior rectal artery. Below the pectineal line the supply is from the inferior and middles rectal arteries

Question 32

Describe the micturition reflex

Answer 32

Involves parasympathetic S2-4 to contract the detrusor muscle, relaxation of involuntary internal urethral sphincter by sympathetics T12-L1, and relaxation of voluntary external urethral sphincter via the pudendal nerve

Question 33

Describe the defaecation process

Answer 33

Faeces collect in lower anal canal, defaecation is inhibited by contraction of internal and external sphincter, stretch of the canal stimulates PNS to inhibit SNS to relax internal anal sphincter and Pudendal nerve voluntarily relaxes external sphincters

Question 34

Describe the erection process

Answer 34

Erection is due to parasympathetic stimulation, there is compression of veins and restriction of venous drainage

Question 35

What is ejaculation mediated by?

Answer 35

The sympathetic nervous system T12-L1

Question 36

What does pain travel with when it is above the pelvic line?

Answer 36

Visceral pain passing with sympathetics

Question 37

What does pain travel with when it is below the pelvic line?

Answer 37

Pain travels with parasympathetics