Pelvic Muscles Flashcards
Where does the levator ani insert?
Perineal body, coccyx, anococcygeal ligament, walls of prostate or vagina, rectum, anal canal
What is the origin of the levator ani?
Body of pubis, tendinous arch of levator ani, ischial spine
What is the innervation of the levator ani?
Nerve to levator ani (branches of S4), inferior anal (rectal) nerve, coccygeal plexus
What action does the levator ani perform?
Helps support pelvic viscera; resists increases in intra-abdominal pleura
Where does the coccygeus insert?
Inferior end of sacrum and coccyx
What is the innervation of the coccygeus?
Branches of S4 and S5 nerves
What action does the coccygeus perform?
Forms small part of pelvic diaphragm that supports pelvic viscera; flexes coccyx
What is the origin of the obturator internus?
Pelvis surface of ilium and ischium; obturator membrane
Where does the obturator internus insert?
Greater trochanter of femur
What is the innervation of the obturator internus?
Nerve to obturator internus (L5, S1, S2)
What action does the obturator internus perform?
Laterally rotates hip joint; assists in holding head of femur in acetabulum
What is the origiin of the piriformis?
Pelvic surface of 2nd-4th sacral segments; superior margin of greater sciatic notch and sacrotuberous ligament
Where does the piriformis insert?
Greater trochanter of femur
What is the innervation of the piriformis?
Anterior rami of S1 and S2
What action does the piriformis perform?
Laterally rotates hip joint; abducts hip joint; assists in holding head of femur in acetabulum
