Pelvic muscles and GI tract

Question 1

Pelvic floor origin

Answer 1

Sacrum, coccyx, ischium, pubis

Question 2

Pelvic floor insertion

Answer 2

Ischial spine, pubis, perineum, rectum, urethra

Question 3

Pelvic floor innervation

Answer 3

S4/S5 spinal nerves AND pudendal nerve

Question 4

Pelvic floor function

Answer 4

Supports the pelvic visera, assists in eliminating waste and giving birth

Notes: Forms a dome-like hammock or sling-often called a “pelvic diaphragm”-think of it like the inverse of the diaphragm.

Question 5

Obturator internus origin

Answer 5

Deep surface of obturator membrane; deep pubic rami & ischium

Question 6

Obturator internus insertion

Answer 6

Medial side of greater trochanter

Question 7

Obturator internus innervation

Answer 7

Nerve to obturator internus

Question 8

Obturators internus function

Answer 8

Laterally rotate thigh at hip when extended; abduct thigh when flexed; postural control

Note: L5/S1 spinal cord level innervation

Question 9

Rectum arises from

Answer 9

Sigmoid colon

Question 10

Rectum enters

Answer 10

Anus

Question 11

Rectum function

Answer 11

Passage of feces out of digestive tract via anus

Note: Hindgut

Question 12

Rectum blood supply

Answer 12

Inferior mesenteric artery via superior rectal branches, internal iliac artery

Question 13

Rectum innervation

Answer 13

pelvic splanchnic nerves S2-S4 (parasympathetic); abdominal sympathetic trunk L1-L2 (sympathetic), sensation pathways: unconcious/reflex & pain (pelvic splanchnic)