Lecture 28: Pelvic Vessels, Nerves and Lymphatics

Question 1

Be able to draw the following: 
abdominal and pelvic arteries
branches of the uterine a. 
rectum blood supply
Pelvic nerves

Answer 1

Ok

Question 2

Common Iliac bifurcates at _____ into _____ and _______

Answer 2

L5- S1 vertebrae; External Iliac A (becomes femoral A.).; Internal Iliac A. (branches to the pelvis and perineum)

Question 3

What consists the posterior division of the Internal Iliac A.?

Answer 3

Posterior division:
Iliolumbar A.
Lateral Sacral A.
Superior Gluteal A.

Question 4

What do these arteries supply?
Iliolumbar
Lateral Sacral
Superior Gluteal

Answer 4

• iliacus, psoas major, QL, cauda equina in vertebral canal
• piriformis, spinal meninges, root of sacral spinal nerves, erector spinae and skin covering dorsal sacrum
• piriformis, gluteal muscles, tensor fascia lata

Question 5

What consists the anterior division of the Internal Iliac A.?

Answer 5

Umbilical A.
Obturator A
Accessory obturator A. (20% of patients) 
Inferior vesical artery (males)
Uterine atery (females)
Vaginal artery (females)
Middle rectal A. 
Internal pudendal A.
Inferior gluteal A.

Question 6

What do these arteries supply?

1. Umbilical A.
2. Obturator A

Answer 6

1. urinary bladder

2. pelvic muscles, head of femur, medial thigh

Question 7

3. Inferior vesical artery (males)
4. Uterine atery (females)
5. Vaginal artery (females)

Answer 7

3. urinary bladder, ureter, prostate, seminal vesicles
4. uterus and ligaments, uterine tube, ovary, superior vagina
5. anterior and posterior vaginal surfaces

Question 8

6 Middle rectal A.

7. Internal pudendal A.
8. Inferior gluteal A.

Answer 8

6. rectum, seminal vesicles, prostate
7. perineum
8. pelvic muscles, piriformis, QF, gluteus maximus, sciatic nerve

Question 9

Course of the superior rectal A.

Answer 9

Origin: Inferior Mesenteric A. > bifurcates at S3 > each branch descends on either side of the rectum (as far down as internal anal sphincter)

Question 10

What venous system drains the pelvic viscera?

What drains this system?

Answer 10

• Pelvic Venous Plexus

- tributaries of the internal iliac veins, inferior mesenteric vein (superior rectal vein) and lateral sacral veins

Question 11

How does blood from the pelvic venous plexus return to the vena cavas?

Answer 11

• Lateral sacral veins have anastomosis with internal vertebral plexus to bring blood to the VCs
• cancer cells can travel to vertebrae from prostate/ovary through this pathway

Question 12

What parts of the pelvic viscera do these nodes drain?
External iliac lymph nodes
Internal iliac lymph nodes
Sacral lymph nodes

Answer 12

• takes lymph from the inguinal nodes and superior parts of middle and anterior pelvic organs
• inferior pelvic viscera, deep perineum, and gluteal region
• postero-inferior pelvic viscera
• All drain to the common iliac nodes

Question 13

What plexus innervates the pelvic structures?

Answer 13

Somatic: sacral and coccygeal spinal nerves

ANS: lumbar, sacral and pelvic splanchnic nerves (via hypogastric plexuses)

Question 14

What nerves exit through the Greater sciatic foramen?

Answer 14

Sciatic n. (L4-s3)
Pudendal N. (s2-s4)
Superior gluteal N. (L4-S1)
Inferior gluteal N. (L4-s2)

Question 15

What do these nerves supply and anatomic significance?
Sciatic nerve
Pudendal nerve

Answer 15

• posterior thigh and entire leg and foot, passes inferior to piriformis
• perineum, enters with internal pudendal artery into lesser sciatic foramen

Question 16

What do these nerves supply and anatomic significance?
Superior gluteal nerve
Inferior gluteal nerve

Answer 16

• gluteus medius and minimus,
• gluteus maxiumus

*both pass superior to piriformis

Question 17

What is the coccygeal plexus and what does it supply?

Answer 17

• anterior rami of S4, S5 and coccyx

- supplies coccygeus muscle, part of levator ani and sacrococcygeal joint

Question 18

What are anococcygeal nerves?

Answer 18

-arise from the coccygeal plexus and supplies the skin between tip of coccyx and anus

Question 19

What supplies sympathetic innervation to pelvic viscera?

What supplies parasympathetic innervation to pelvic viscera?

Answer 19

Lumbar and sacral splanchnic nerves - synapse at hypogastric plexuses

Pelvic splanchnic nerves - S2-4 (also PNS to descending colon and distal structures)

Question 20

What are the main sympathetic contributors to the pelvic viscera?

Answer 20

1. ) Lumbar splanchnic nerves > synapse at superior hypogastric plexus > ureter/testes OR synapse at inferior hypogastric plexus to pelvic plexuses that innervate visceral targets
2. ) Sacral splanchnic nerves > synapse at inferior hypogastric plexus > rectal/vesical plexus to various pelvic targets

Question 21

What is the pathway of parasympathetic innervation to viscera?

Answer 21

Pelvic splanchnic nerves (S2-s4) > synapse at inferior hypogastric plexus > post ganglionics to pelvic viscera

Question 22

What are sub-plexuses and how are they similar/different in males/females?

Answer 22

refers to branches of the inferior hypogastric plexus that carries signals to various pelvic organs

Similarity in male/female: both associated with lateral rectum and inferolateral urinary bladder

Male: associated with prostate and seminal vesicles, penetrate the pelvic diaphragm to reach the erectile structures

Female: associated with the cervix and lateral fornices