Chapter 27 Development of the external genitalia

Question 1

How does the development of the genitals differ between male and female in the embryo?

Answer 1

Both develop from identical structures

Question 2

What does the embryo have by the 6 week mark?

Answer 2

the genital tubercle, an anterior median bud

urogenital folds, a pair of medial tissue folds slightly posterior to the genital tubercle

labioscrotal folds - a larger pair of tissue folds lateral to the urogenital folds

Question 3

When does the fetus begin to show sexual differentiation?

Answer 3

at the end of week 9

Question 4

What does the genital tubercle turn into for men?

Answer 4

the phallus

Question 5

What do the urogenital turn into for men?

Answer 5

they fuse to enclose the urethra, joining the phallus to form the penis

Question 6

what do the labioscrotal folds form in men?

Answer 6

they fuse to form the scrotum which is a sac that will later contain the testes

Question 7

What are male and female organs that develop from the same embryonic structure referred to as?

Answer 7

they are said to be homologous.

homologous = Having the same embryonic or evolutionary origin but not necessarily the same function, such as the scrotum and labia majora. 2. Pertaining to two chromosomes with identical structures and gene loci but not necessarily identical alleles; each member of the pair is inherited from a different parent.

penis = clitoris
scrotum = labia majora

Question 8

What happens in the presence of excess androgen in a female?

Answer 8

the clitoris may become greatly enlarged and resemble a small penis.