Muscles of the perineum

Question 1

transverse perineal muscle- origin

Answer 1

inferior pubic ramus and ischial ramus

Question 2

transverse perineal muscle- insertion

Answer 2

central tendon (perineal body)

Question 3

transverse perineal muscle- action

Answer 3

supports pelvic viscera; anchors external genitalia

Question 4

transverse perineal muscle- innervation

Answer 4

pudendal nerve

Question 5

external urethral sphincter- origin & insertion

Answer 5

encircles the urethra (embedded in transverse perineal mm)

Question 6

external urethral sphincter- action

Answer 6

voluntary constriction of urethra, turns off urinary reflex

Question 7

external urethral sphincter- innervation

Answer 7

pudendal nerve

Question 8

external anal sphincter- origin & insertion

Answer 8

encircles the anus and attaches to central tendon

Question 9

external anal sphincter- action

Answer 9

voluntary constriction of anus, turns off defecatory reflex

Question 10

external anal sphincter- innervation

Answer 10

pudendal nerve

Question 11

bulbospongiosus- origin & insertion

Answer 11

runs anteriorly from central tendon to clitoris (females) or midline raphe (males)

Question 12

bulbospongiosus- action

Answer 12

helps produce & maintain erection of clitoris & penis
helps empty spongy urethra (male)

Question 13

bulbospongiosus- innervation

Answer 13

pudendal nerve

Question 14

ischiocavernosus- origin

Answer 14

ischial ramus

Question 15

ischiocavernosus- insertion

Answer 15

crus of clitoris or penis

Question 16

ischiocavernosus- action

Answer 16

maintains erection by squeezing blood into corpus cavernosum

Question 17

ischiocavernosus- innervation

Answer 17

pudendal nerve