Abd/Pelvic Mm - Innervations

Question 1

rectus abdominis

Answer 1

ventral rami of T7-T12

Question 2

external oblique

Answer 2

ventral rami of T7-T12, iliohypogastric portion of L1

Question 3

internal oblique

Answer 3

ventral rami of T7-T12, iliohypogastric portion of L1, ilioinguinal portion of L1

Question 4

transverse abdominis

Answer 4

ventral rami of T7-T12, all of L1 (iliohypogastric portion of L1, ilioinguinal portion of L1)

Question 5

quadratus lumborum

Answer 5

ventral rami of T12-L4

Question 6

iliacus

Answer 6

femoral n (L2, L3, L4)

Question 7

psoas major

Answer 7

ventral rami of L1-L3

Question 8

piriformis

Answer 8

n to piriformis (S1-S2)

Question 9

obturator internus

Answer 9

n to obturator internus (L5-S2)

Question 10

ischiococcygeus

Answer 10

ventral rami of S3-S4

Question 11

levator ani (puborectalis, pubococcygeal, iliococcygeal)

Answer 11

S3-S4, perineal b of pudendal n

Question 12

superficial transverse perineus

(*perineum mm all same inn except ext anal sphincter)

Answer 12

perineal b of pudendal n

Question 13

bulbospongiosus

(*perineum mm all same inn except ext anal sphincter)

Answer 13

perineal b of pudendal n

Question 14

ischiocavernosus

(*perineum mm all same inn except ext anal sphincter)

Answer 14

perineal b of pudendal n

Question 15

deep transverse perineus

(*perineum mm all same inn except ext anal sphincter)

Answer 15

perineal b of pudendal n

Question 16

external urethral sphincter

(*perineum mm all same inn except ext anal sphincter)

Answer 16

perineal b of pudendal n

Question 17

external anal sphincter

(*only perineum mm with unique inn)

Answer 17

inferior rectal branch of pudendal n & S4

Question 18

in what direction do the nerves of the posterior abdominal wall travel?

Answer 18

cranial to caudal

Question 19

in what direction do the nerves of the posterior abdominal wall travel?

Answer 19

cranial to caudal

Question 20

what nerve pierces the psoas major mm

Answer 20

genitofemoral n. (L1-L2)

Question 21

what nerve is deep to the psoas major?

Answer 21

femoral n. (L2-L4)

Question 22

name the 5 perineum mm innervated by the perineal b. of pudendal nerve?

Answer 22

1. superifical transverse perineal
2. bulbospongiosus
3. ischiocavernosus
4. deep transverse perineal
5. external urethral sphincter

Question 23

what makes the external anal sphincter unique?

Answer 23

innervated by the inferior rectal br. of pudendal nerve and S4