Pelvic Nerves and Vessels

Question 1

What is the root value of the sacral plexus

Answer 1

L4-S5

Question 2

What is the largest nerve coming from the sacral plexus, and what is its root value

Answer 2

The sciatic nerve, and L4-S3

Question 3

What area does the sciatic nerve supply

Answer 3

It supplies motor and sensory innervation to the posterior compartment of the thigh, and the leg and foot

Question 4

How many gluteal nerves do we have; name them

Answer 4

2; superior and inferior gluteal nerves

Question 5

What is the root value of the gluteal nerves

Answer 5

Superior = L4-S1
Inferior = L5-S2

Question 6

What muscle is in between the gluteal nerves

Answer 6

Piriformis

Question 7

Which gluteal muscles are supplied by which nerve

Answer 7

Superior = gluteus medius and minimus
Inferior = gluteus maximus

Question 8

What is the root value of the nerve to obturator internus

Answer 8

L5-S2

Question 9

What muscles does the nerve to obturator internus supply

Answer 9

Obturator internus and superior gamellus

Question 10

What is the root value of the nerve to piriformis

Answer 10

S1-S2

Question 11

What is the root value of the pudendal nerve

Answer 11

S2-S4

Question 12

What are the 5 main structures that are supplied by the pudendal nerve

Answer 12

1. Levator ani
2. External anal sphincter
3. External urethral sphincter
4. Bulbospongiosus
5. Ischiocavernosus

Question 13

What is the root value of the nerve to levator ani

Answer 13

S4

Question 14

What is the root value of the nerve to coccygeus

Answer 14

S4-S5

Question 15

What autonomic plexus’ innervate the pelvic region

Answer 15

Superior hypogastric plexus (x1)

Inferior hypogastric plexus (x2)

Question 16

What is the root value of the pelvic splanchnic nerve

Answer 16

S2-S4

Question 17

Where is the superior hypogastric plexus located

Answer 17

Close to the bifurcation of the abdominal aorta

Question 18

Describe 3 examples of sympathetic innervation in the pelvis

Answer 18

1. Contraction of the internal anal and urethral sphincters
2. Relax the detrusor muscle of the bladder
3. During ejaculation, contraction of the vas deferens and seminal vesicles

Question 19

Describe 3 examples of parasympathetic innervation in the pelvis

Answer 19

1. Increase motility of the rectum and anal canal
2. Vasodilation of the arteries of the penis; during erection
3. Relax the internal anal and urethral sphincters

Question 20

Describe where the S1 dermatome is

Answer 20

Posterior surface of the heel and the plantar surface of the foot

Question 21

Describe where the S2 dermatome is

Answer 21

It runs down the posterior surface of the thigh

Question 22

At what level does the abdominal aorta bifurcate, and what arises

Answer 22

At L4, and the 2 common iliacs arise

Question 23

What do the internal iliacs divide further into

Answer 23

Anterior and posterior branches

Question 24

Name the 6 main arteries that branch from the anterior division of the internal iliac artery

Answer 24

1. Umbilical artery; gives rise to superior vesical
2. Obturator
3. Inferior vesical
4. Middle rectal
5. Internal pudendal
6. Inferior gluteal

Question 25

In males, what branch does the inferior vesical artery give rise to

Answer 25

The prostatic artery

Question 26

Is the inferior vesical artery present in females

Answer 26

No

Question 27

What artery is present in females instead of the inferior vesical; and what does it give rise to

Answer 27

Uterine artery; gives rise to the vaginal artery

Question 28

Name the 3 main arteries that branch from the posterior division of the internal iliac

Answer 28

1. Iliolumbar 2. Lateral sacral 3. Superior gluteal

Question 29

What viscera receive their blood supply directly from the abdomen

Answer 29

Testes in males, and ovaries in females

Question 30

What vessel does the majority of blood from the pelvis drain to

Answer 30

The internal iliac vein; common iliac vein; IVC