Pelvic muscles and GI tract Flashcards
Pelvic floor origin
Sacrum, coccyx, ischium, pubis
Pelvic floor insertion
Ischial spine, pubis, perineum, rectum, urethra
Pelvic floor innervation
S4/S5 spinal nerves, pudendal nerve
Pelvic floor function
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.
Obturator internus origin
Deep surface of obturator membrane; deep pubic rami & ischium
Obturator internus insertion
Medial side of greater trochanter
Obturator internus innervation
Nerve to obturator internus
Obturators internus function
Laterally rotate thigh at hip when extended; abduct thigh when flexed; postural control
Note: L5/S1 spinal cord level innervation
Rectum arises from
Sigmoid colon
Rectum enters
Anus
Rectum function
Passage of feces out of digestive tract via anus
Note: Hindgut
Rectum blood supply
Inferior mesenteric artery via superior rectal branches, internal iliac artery
Rectum innervation
pelvic splanchnic nerves S2-S4 (parasympathetic); abdominal sympathetic trunk L1-L2 (sympathetic), sensation pathways: unconcious/reflex & pain (pelvic splanchnic)