Development of cloaca (dave's notes)

Question 1

What is the cloaca?

Answer 1

The meeting of the hind gut and allantois bound by the cloacal membrdane

Question 2

How does the hind gut meet the cloacal membrane?

Answer 2

The urorectal septum grows downwards to meet the cloacal membrane

Question 3

What are the three parts of the urogenital sinus?

Answer 3

Highest (vesicle)
Middle (pelvic)
Lowest (phallic)

Question 4

What does the highest part of the urogenital sinus become? How?

Answer 4

The bladder. In the female, the urethra. In the male, the proximal prostatic urethra.
The lower end of the mesonephric duct opens here and the ureter forms a bud

Question 5

What does the middle part of the urogenital sinus become?

Answer 5

Female: Contributes to the vagina
Male: Prostate, remainder of the prostatic urethra, and membranous urethra

Question 6

What does the lowest part of the urogenital sinus become?

Answer 6

The genital tubercle and urogenital folds
And in females: the vaginal vestibule
In males, dorsal penis

Question 7

What do the urogenital folds become?

Answer 7

Females - labia minora

Males - scrotum, ventral penis and urethra