Pelvic Viscera Blood Supply and Nervous Innervation

Question 1

Neurovascular organization of the pelvis:

Answer 1

• NVA runs within endopelvic fascia.
• Arranged in concentric layers, lateral to medial: SVA
  
  • somatic nerves (lateral)
  • blood vessels
  • autonomic nerves (medial)

Question 2

Label all:

Answer 2

• NVA of pelvis; lateral to medial: SVA
  
  • somatic nerves (yellow)
  • blood vessels (blue/red)
  • autonomic nerves (white)

Question 3

Label all:

Answer 3

Question 4

Largest nerve passing through the greater sciatic foramen:

Answer 4

• sciatic nerve (L4-S3). Joins with the lumbosacral trunk before exiting.

Question 5

Route of lumbosacral trunk to it union with the sciatic nerve:

Answer 5

crosses over pelvic brim

Question 6

Somatic nerves making up the lateral component of the pelvic neurovasculature are the:

Answer 6

• obturator nerve, sciatic nerve, and pudendal nerve.
• Lumbosacral trunk passes over the pelvic brim to unite with sciatic.

Question 7

Label all:

Answer 7

Question 8

Primary blood supply to pelvic structures:

Answer 8

• arterial: branches of internal iliac artery
• venous: branches of internal iliac vein

Question 9

The two trunks of the internal iliac artery and their target blood supply:

Answer 9

• posterior division: blood supply to pelvic body wall.
• anterior division: blood supply to pelvic viscera.

Question 10

The superior gluteal artery typically passes posteriorly between what two structures to enter the gluteal region from the pelvis?

Answer 10

• lumbosacral trunk and S1

Question 11

The inferior gluteal artery typically passes from the pelvis to the gluteal region by exiting between what two structures?

Answer 11

• piriformis and coccygeus, typically between S2 and S3.

Question 12

Lymphatics of the pelvis follow along what structures:

Answer 12

• vasculature of the respective pelvic viscera.
  
  • ovary = ovarian artery (branch of abdominal aorta)
  • uterus = uterine artery (branch of internal iliac)

Question 13

Blood supply to ovary and derivation:

Answer 13

• ovarian artery.
• branch of abdominal aorta near kidney level.

Question 14

Blood supply to cervix/uterus and derivation:

Answer 14

• uterine artery.
• branch of internal iliac artery.

Question 15

How will ovarian cancer metastasize?

Answer 15

• follow vasculature (ovarian artery and vein).
• spread along the lateral aortic lymph nodes.

Question 16

How will cervical cancer metastasize?

Answer 16

• follow vasculature (uterine artery).
• spread along internal iliac lymph nodes.

Question 17

Two important characteristics of the uterine arteries:

Answer 17

1. pass superior to ureter (“water under the bridge”).
2. course within transverse cervical (cardinal) ligaments.

Question 18

Function of pelvic sympathetic nervous innervation (3):

Answer 18

• vasoconstriction of pelvic arteries
• contraction of smooth muscle sphincters
• (Males) peristalsis of sperm through vas deferens

Question 19

The two sphincters controlled by pelvic sympathetic nervous innervation and effect of this innervation:

Answer 19

• internal urethral sphincter.
• internal anal sphincter.
• Sympathetics keep tonically closed so can fill.

Question 20

Function of pelvic parasympathetic nervous innervation (3):

Answer 20

• contraction of detrusor muscle (bladder excretion).
• rectal peristalsis.
• inhibit smooth muscle sphincters (urethral and anal).

Question 21

How are the internal urethral sphincter and internal anal sphincter relaxed so that they can be emptied?

Answer 21

• parasympathetics inhibit sympathetic tonic contraction of these sphincters.
• sphincters then relax.

Question 22

Label all (pelvis):

Answer 22

Question 23

Location of PREganglionic sympathetic cell bodies innervating the pelvic visecera:

Answer 23

lateral horn L1 and L2.

Question 24

Location of POSTganglionic sympathetic cell bodies innervating the pelvic visecera:

Answer 24

1. superior mesenteric plexus
2. inferior mesenteric plexus
3. inferior hypogastric plexus

Question 25

Route of the sympathetic innervation to the pelvis with postganglionic cell bodies in the inferior mesenteric plexus:

Answer 25

1. L1/L2 lateral horn 2. white rami into sympathetic chain 3. lumbar splanchnics 4. synapse on inferior mesenteric plexus on aorta 5. through superior hypogastric plexus 6. through hypogastric nerve 7. through inferior hypogastric plexus 8. to the pelvic organ it will innervate.

Question 26

Route of the sympathetic innervation to the pelvis with postganglionic cell bodies in the inferior mesenteric plexus using the LUMBAR splanchnics:

Answer 26

1. L1/L2 lateral horn 2. white rami into sympathetic chain 3. lumbar splanchnics 4. through inferior mesenteric plexus on aorta 5. through superior hypogastric plexus 6. through hypogastric nerve 7. synapse in inferior hypogastric plexus 8. to the pelvic organ it will innervate.

Question 27

Route of the sympathetic innervation to the pelvis with postganglionic cell bodies in the inferior mesenteric plexus using the SACRAL splanchnics:

Answer 27

1. L1/L2 lateral horn 2. white rami into sympathetic chain 3. down sympathetic chain 4. through sacral splanchnics 5. synapse in inferior hypogastric plexus 6. to the pelvic organ it will innervate.

Question 28

The two splanchnic nerves carrying preganglionic sympathetic nerve fibers to the pelvis, and where these fiber synapse:

Answer 28

1. lumbar splanchnics * synapse in inferior mesenteric plexus or inferior hypogastric plexus. 2. sacral splanchnics * synapse in inferior hypogastric plexus only.

Question 29

Location of PREganglionic parasympathetic cell bodies innervating the pelvic visecera:

Answer 29

spinal cord segments S2, S3, S4.

Question 30

Route of the parasympathetic innervation to the pelvis:

Answer 30

1. preganglionic cells bodies in S2, S3, S4. 2. pelvic splanchnic nerves. 3. synapse in inferior hypogastric plexus. 4. to the pelvic organ it will innervate.

Question 31

Visceral afferent nerves running on sympathetic nerves; sensation conveyed and region supplied:

Answer 31

* pain sensation * peritoneal structures (covered by peritoneum) * above pelvic pain line

Question 32

Visceral afferent nerves running on parasympathetic nerves; sensation conveyed and region supplied:

Answer 32

* pain sensations and reflexes * reflex: entire pelvis * pain: subperitoneal (not covered by peritoneum) * below pelvic pain line

Question 33

Pelvic pain line:

Answer 33

* organs above covered in peritoneum; pain carried on sympathetics. * organs below NOT covered in peritoneum; pain carried on parasympathetics.

Question 34

Organs above pelvic pain line covered in peritoneum with pain afferents carried on sympathetics and where pain felt:

Answer 34

* fundus and body of uterus, uterine tubes, ovaries. * pain referred to L1/L2 dermatomes. * lower back and suprapubic pain.

Question 35

Organs below pelvic pain line NOT covered in peritoneum with pain afferents carried on parasympathetics and where pain felt:

Answer 35

* cervix, upper vagina, and bladder. * pain referred to S2-S4 dermatomes. * lower leg pain.

Question 36

Route of pain sensation above the pelvic pain line to CNS:

Answer 36

**along sympathetics** 1. inferior hypogastric plexus 2. hypogastric nerve 3. superior hypogastric plexus 4. lumbar splanchnics 5. L1/L2 dorsal horn

Question 37

Route of pain sensation below the pelvic pain line to CNS:

Answer 37

**along parasympathetics** 1. inferior hypogastric plexus 2. pelvic splanchnics 3. S2-S4 dorsal horn

Question 38

Nerve fiber types in superior hypogastric plexus:

Answer 38

* pre and postganglionic sympathetics * visceral afferents above pelvic pain line

Question 39

Nerve fiber types in hypogastric nerves:

Answer 39

* pre and postganglionic sympathetics * visceral afferents above pelvic pain line

Question 40

Nerve fiber types in inferior hypogastric plexus:

Answer 40

* pre and postganglionic sympathetics * pre and postganglionic parasympathetics * visceral afferents

Question 41

Nerve fiber types found in pelvic splanchnic nerves:

Answer 41

* preganglionic parasympathetics * visceral afferents below pelvic pain line

Question 42

Nerve fiber found in lumbar splanchnic nerves:

Answer 42

* preganglionic parasympathetics * visceral afferents above pelvic pain line