muscles of the pelvic outlet

Question 1

name the muscles of the pelvic outlet

Answer 1

coccygeus
levator ani
rectococygeus
external anal sphincter

Question 2

origin and insertion of the coccygeus

Answer 2

ischiatic spine to 2nd - 5th coccygeal vertebrae

Question 3

action of the coccygeus

Answer 3

tail depressor

Question 4

innervation of the coccygeus

Answer 4

3rd sacral nerve

Question 5

origin and insertion of the levator ani

Answer 5

medial ilium to 7th coccygeal vertebrae

Question 6

action of the levator ani

Answer 6

depressor of tail - causes characterictic kinking of tail during defecation
compression of rectum

Question 7

innervation of the levator ani

Answer 7

3rd sacral and 4th coccygeal nerves

Question 8

origin and insertion of the external anal sphincter

Answer 8

covers the internal sphincter

Question 9

action of the external anal sphincter

Answer 9

close rectum

Question 10

innervation of the external anal sphincter

Answer 10

sacral nerves

Question 11

origin and insertion of the rectococcygeus

Answer 11

continuation of the smooth muscle fibres of the rectum
inserts 3rd - 6th coccygeal vertebrae

Question 12

action of the rectococcygeus

Answer 12

acts as anchor to rectum and provides caudal traction during defecation

Question 13

innervation of the rectococcygeus

Answer 13

autonomic fibres from the pelvic plexus