Pelvis Neurovasculature

Question 1

What are the divisions of the internal iliac artery?

Answer 1

Anterior and posterior

Question 2

Briefly describe the course of the superior gluteal arteries

Answer 2

Run posteriorly between lumbosacral trunk and S1, then exit pelvis via greater sciatic foramen superior to piriformis muscle

Question 3

Give the rule of pelvic venous drainage and two exceptions to that rule

Answer 3

Rule - Internal Iliacs to Common Iliacs to IVC. Exception 1 - Lateral sacral veins to Internal vertebral venous plexuses. Exception 2 - Superior rectal veins to portal system.

Question 4

Four main types of pelvic lymph nodes

Answer 4

External iliac, internal iliac, sacral, common iliac

Question 5

What do each of the four types of pelvic lymph nodes drain?

Answer 5

Sacral - Posteroinferior pelvic viscera, External Iliac - Pelvic viscera, inguinal nodes, Internal Iliac - Inferior pelvic viscera, deep perineum, gluteal region, Common iliac - Inferior structures drain up to them and they drain to lumbar (caval/aortic) nodes

Question 6

What cutaneous nerve innervates the largest skin area of any in the body?

Answer 6

The posterior femoral cutaneous nerve (S1-S3)

Question 7

Innervation of quadratus femoris and inferior gamellus

Answer 7

L4-S1 via sacral plexus

Question 8

Innervation of obturator internus and superior gamellus

Answer 8

L5-S2 via sacral plexus

Question 9

Innervation of piriformis muscle

Answer 9

S1-S2 via sacral plexus

Question 10

Where does the obturator nerve originate and where does it go?

Answer 10

Originates in lumbar plexus (L2-L4) and goes to medial thigh

Question 11

Where does the obturator nerve pass through the pelvis?

Answer 11

On the pelvic sidewall and out the obturator foramen

Question 12

4 main types of pelvic autonomic nerves

Answer 12

Sacral sympathetic trunks, periarterial plexuses, hypogastric plexuses, pelvic splanchnic nerves

Question 13

Where do the sacral sympathetic trunks run relative to the pelvic foramina?

Answer 13

Medial to the foramina

Question 14

How many ganglia do the sacral sympathetic trunks usually have?

Answer 14

4

Question 15

Ganglion impar

Answer 15

A structure formed by the convergence of 2 ganglia of the pelvic sympathetic trunk

Question 16

Periarterial nervous plexuses of the pelvis run with which arteries?

Answer 16

Superior rectal, ovarian, internal iliac

Question 17

What is the function of periarterial nervous plexuses of the pelvis?

Answer 17

Vasomotion of the arteries

Question 18

What do pelvic splanchnic nerves carry (include fiber type, system, post/presynaptic, and origin)?

Answer 18

Presynaptic parasympathetic GVA fibers from S2, S3 and S4

Question 19

Where are the superior hypogastric plexuses and what are they formed from?

Answer 19

Just inferior to bifurcation of the aorta, formed as continuation of intermesenteric and inferior mesenteric plexuses

Question 20

What fibers are carried by the superior hypogastric plexus?

Answer 20

GVA Postsynaptic sympathetic nerve fibers

Question 21

What plexuses are supplied by the superior hypogastric plexuses?

Answer 21

Ureteric and testicular plexuses

Question 22

Are the superior hypogastric and inferior hypogastric plexuses connected and if so by what?

Answer 22

Yes, by the right and left hypogastric nerves

Question 23

Generally speaking, the inferior hypogastric plexuses provide what type of innervation to where?

Answer 23

Autonomic innervation to the pelvic viscera

Question 24

Nerves of the inferior hypogastric plexuses spread and join with what?

Answer 24

Pelvic splanchnic nerves

Question 25

Generally speaking, where are sympathetic and parasympathetic fibers relayed through the pelvic plexuses?

Answer 25

Sympathetic fibers via the hypogastric plexuses, parasympathetic fibers via the pelvic splanchnic nerves

Question 26

List the purely sympathetic components of the pelvis

Answer 26

1) Aortic/intermesenteric plexuses, 2) Sacral splanchnic nerves, 3) Ganglion impar, 4) Internal Iliac periarterial plexuses, 5) Sacral/lumbar sympathetic trunks, 6) Left/Right hypogastric nerves, 7) Superior hypogastric plexus, 8) Inferior mesenteric/superior rectal periarterial plexuses

Question 27

List the purely parasympathetic components of the pelvis

Answer 27

Pelvic splanchnic nerves

Question 28

List the mixed autonomic components of the pelvis

Answer 28

Inferior hypogastric plexuses, ovarian periarterial plexuses

Question 29

List the somatic components of the pelvis

Answer 29

Pudendal nerve, sciatic nerve

Question 30

What do sympathetic fibers of the pelvis do?

Answer 30

Produce vasomotion, contraction of internal genital organs during orgasm, inhibit rectal peristalsis

Question 31

What do parasympathetic fibers of the pelvis do?

Answer 31

Stimulate bladder and rectal emptying, extend to the erectile bodies of external genitalia to produce erection

Question 32

What do visceral afferent fibers of the pelvis convey and to where do they convey it?

Answer 32

Unconscious reflex sensation to spinal sensory ganglia of S2-S4

Question 33

Where is the pelvic pain line?

Answer 33

Inferior limit of the peritoneum

Question 34

What do visceral afferent fibers follow superior to the pelvic pain line?

Answer 34

Sympathetic fibers

Question 35

What do visceral afferent fibers follow inferior to the pelvic pain line?

Answer 35

Parasympathetic fibers