Perineum and External Genitalia

Question 1

What boundary is represented by the pectinate line?

Answer 1

Divides upper 2/3 and lower 1/3 of anal canal

Question 2

What structures form the borders of the ishioanal fossae?

Answer 2

Medial - External anal sphincter levator ani
Lateral - Ischial tuberosity, obturator internus muscle
Inferior - Deep transverse perineal fascia

Question 3

What branches of internal pudendal artery supply the erectile tissue of the penis and the clitoris and vestibule in females?

Answer 3

Cavernous arteries

Question 4

From what vessel does the external pudendal artery branch?

Answer 4

Femoral artery

Question 5

What are the actions of the bulbospongiosus and ischiocavernosus muscle?

Answer 5

Bulbospongiosus - Expels urine from urethra after bladder is empties and aids in final stages of erection by compressing veins
Ischiocavernosus - compress crus of penis to maintain and stabilise erect penis, maintain clitoral erection

Question 6

What is the mechanism of penile erection?

Answer 6

Muscle of corpus cavernous to relax allowing blood to fill into open spaces creating pressure and penis expands

Question 7

What is the sensory nerve supply to the skin of the scrotum?

Answer 7

Iliohypogastric nerve

ilioinguinal nerve

Question 8

What is the function of the vestibular glands (Bartholins glands)?

Answer 8

Produce mucous - mucoid secretion aids in vaginal/ vulvar lubrication