Perineum

Question 1

Borders of anal triangle

Answer 1

Ischial tuberosities

Coccyx

Question 2

Borders of Urogenital triangle

Answer 2

Ischail tuberosities

Pubic symphysis

Question 3

Columns

Answer 3

longitudinal ridges in anal canal

Question 4

Pectinate line

Answer 4

indicates where anal columns end
divides the origin of nerves and vessels
former site of cloacal membrane

Question 5

Cloacal membrane

Answer 5

membrane present at pectinate line during development

Question 6

Origin of NAV above pectinate line

Answer 6

A: inf mesenteric
N: visceral motor (parasym, sym), sensory
V: portal sys

Question 7

Origin of NAV below pectinate line

Answer 7

A: int iliac
N: somatic motor and sensory
V: caval sys

Question 8

Line connecting what landmarks divides pelvic outlet into UG and anal triangles?

Answer 8

Ischial tuberosities

Question 9

Contents of superficial perineal pouch in both males and females

Answer 9

Ischiocavernosus
Bulbospongiosus
Superficial transverse perineal muscles
Deep perineal branches of int pudendal vessels and pudendal nerves

Question 10

Ischiocavernosus male vs female

Answer 10

Male and female – split

Question 11

Bulbospongiosus male vs female

Answer 11

Male: fused at center
Female: split

Question 12

Location of superficial transverse perineal muscle

Answer 12

along line dividing UG and anal triangles

Question 13

Midpoint of superficial transverse perineal muscle

Answer 13

perineal body

Question 14

Spongy erectile tissue covered by ischiocavernosus in male and female

Answer 14

Corpus cavernosum (of penis/clitoris)

Question 15

Spongy erectile tissue covered by bulbospongiosum in male and female

Answer 15

Corpus spongiosum (single structure in males, paired in females)

Question 16

Deep perineal pouch contents

Answer 16

Ext urethral sphincter
Compressor urethrae *small in males – part of ext urethral sphincter)
Deep transverse perineal muscle (skeletal in males, smooth in females)
Membranous urethra (males)

Question 17

What structure is the floor of the perineal pouch?

Roof?

Answer 17

Floor: Levator ani
Roof: perineal membrane

Question 18

Innervation of anal triangle

Answer 18

pudendal nerve (back of pelvis)
Inf anal splits off
pudendal --> inf rectal runs through pudendal canal --> perineal nerve when exits canal --> splits into dorssal nerve of penis/clitoris and post scrotal/labia majora

Question 19

Blood supply of anal triangle

Answer 19

Int pudendal a
Inf anal splits off
int pudendal becomes perineal –> branches to ext genitalia

Question 20

Spongy tissue in male perineum

Answer 20

Corpora cavernosum (paired)
Corpus spongiosum (singular, contains spongy urethra)

Question 21

What spongy erectile tissue in male ends?

Which extends out to glans penis?

Answer 21

Ends: corpora cavernosum

Extends to glans: spongiosum

Question 22

Arterial supply of male perineum

Answer 22

Dorsal aa of penis (paired)
Deep aa of penis (paired, in corpora cavernosa)
Both sets of aa are branches from int pudendal a

Question 23

Venous supply of male perineum

Answer 23

One dorsal v of penis

Drains to prostatic venous plexus

Question 24

Innervation of male perineum

Answer 24

Sym: Pudendal –> perineal –> post scrotal and dorsal n of penis
Parasum: pelvic splanchnic nerves –> form cavernous nerve plexus

Question 25

Pudendal n – parasym or sym?

Answer 25

Sym (motor and sensory)

Question 26

Cavernous nerves cause…in males

Answer 26

vasodilation of aa in spongy erectile tissue

Question 27

Cavernous nerves originate from…

Answer 27

prostatic plexus (from pelvic sphlanchnic)

Question 28

Innervation of female perineum

Answer 28

Post labial n (from perineal n, from pudendal n)

Dorsal n of clitoris (from pudendal)

Question 29

Blood supply of female perineum

Answer 29

Post labial aa (from perineal a, from int pudendal a)

Dorsal a of clitoris (from int pudendal)