Perineum

Question 1

What is the perineum?

Answer 1

the region beneath the pelvic floor, between the thighs and above the skin

Question 2

What are the borders of the perineum?

Answer 2

pubic symphysis, ischial tuberosities and the coccyx

Question 3

What regions is the perineum divided into and what divides them?

Answer 3

the urogenital triangle and the anal triangle - divided by the line between the ischial tuberosities

Question 4

What is the perineal membrane?

Answer 4

a membrane which further subdivides the urogenital triangle into a superficial perineal pouch and deep perineal pouch

Question 5

What is the perineal body?

Answer 5

a thickening in the centre of the free edge of the perineal membrane - serves as an anchor for the sphincters associated with the termination of the urogenital tract and gastrointestinal tract

Question 6

What are the transverse perineal muscles?

Answer 6

the 4 muscles (2 superficial, 2 deep) associated with the posterior margin of the perineal membrane

Question 7

What is in the anal triangle?

Answer 7

the anal canal and the ischiorectal fossae (filled with fat)

Question 8

What is the pudendal canal?

Answer 8

a canal in the fascia overlying obturator internus which contains the neurovascular bundle for the perineum

Question 9

What delineates the upper 2/3rds and lower 1/3rd of the anus?

Answer 9

the pectinate line

Question 10

What are the differences between the upper 2/3rds and lower 1/3rd of the anus?

Answer 10

the upper 2/3rds has mucosa and the lower 1/3rd has skin, the upper 2/3rds is supplied by the superior rectal artery and the lower 1/3rd is supplied by the inferior rectal artery, the upper 2/3rds drains into the portal system and the lower 1/3rd drains into the systemic and the upper 2/3rds has autonomic nerve supply and the lower 1/3rd has somatic

Question 11

What is the internal anal sphincter?

Answer 11

a thickening in the smooth muscle wall which is under autonomic control

Question 12

What are the 3 parts of the external anal sphincter?

Answer 12

the deep part which fuses with puborectalis, the superficial part which is anchored to the coccyx and perineal body and the subcutaneous part which is a flat circular band immediately beneath the skin

Question 13

What is an episiotomy?

Answer 13

a controlled cut away from the perineal body to avoid tearing of the perineal body in child birth

Question 14

What is located in the deep perineal pouch?

Answer 14

sphincters

Question 15

What is located in the superficial perineal pouch?

Answer 15

anchor points of the external genitalia

Question 16

What is the paraurethral gland?

Answer 16

a gland in the superficial perineal pouch of females which opens into the urethra

Question 17

What is the greater vestibular gland?

Answer 17

a gland in the superficial perineal pouch of females which opens into the vagina

Question 18

What are the four parts of the male urethra?

Answer 18

preprostatic part at the bladder neck, prostatic part through the prostate, membranous part which traverses the deep perineal pouch and the perineal membrane and the spongy part which traverses the penis

Question 19

What is the internal urethral sphincter?

Answer 19

a sphincter at the neck of the bladder to prevent reflux of semen into the bladder- under autonomic control

Question 20

Where is the bulbourethral gland located?

Answer 20

deep perineal pouch

Question 21

What makes up the external male genitalia?

Answer 21

paired corpora cavernosa and a single corpus spongiosum

Question 22

What muscles cover the penis?

Answer 22

ischiocavernosus and bulbospongiosus

Question 23

What nerves fibres are carried via the pudendal nerve?

Answer 23

sensory, sympathetic and somatic motor of S2-4

Question 24

What is the path of the pudendal nerve?

Answer 24

exits the pelvis with piriformis via the greater sciatic foramen, winds around the back of the ischial spine, goes back through the lesser sciatic foramen to the pudendal canal

Question 25

What are the branches of the pudendal nerve?

Answer 25

inferior rectal nerve, perineal nerve (motor and cutaneous branches) and the dorsal nerve of penis or clitoris