Reproductive System

Question 1

Why is the reproductive system considered bipotential?

Answer 1

Because it can go on to form either male or female, female being the dominant form dependent on the genetic sex.

Mesonephric duct - wolffian ducts
Parameonephric duct - mullarian duct

Switch on the Y chromosome “SRY region/gene” pushes towards male

Question 2

How can an embryonic gonad go on to form either the ovaries or the testes?

Answer 2

In the medulla you have sex cords that give rise to seminferious tubules with Seattle cells in genetic male

Along side the sex cords are the rete cords where the medulla regresses and the cortex forms the ovary.

Btwn the medulla and the cortex there is a CT layer called tunica albuginea

• external surface of the testes
• internal surface of the ovaries

Question 3

what organisms are ammonotelic? what does this say about them?

Answer 3

Freshwater teleosts and lungfish
Excrete nitrogen as their waster product - very dilute urine
Large corpuscle

Question 4

What are the two ducts that form the nonspecific embryo reproductive system?

Answer 4

Mesonephric, wolffian, duct

Mullerian duct - or paramesonephric

Both empty into the cloaca

Question 5

Which structures/ducts degenerate and which persist in the female phenotype?

Answer 5

Mullarian ducts form oviducts

Medulla, rete cords and mesonephric ducts degenerate (also called archinephric)

Question 6

Whic hstructure persist in males reproductive system and which degenerate?

Answer 6

mesonephric ducts are retained as efferent ductules

-if used mostly for sperm transport: ductus deferents/van deferents

Connects with additional ducts to make a closed system

Mullarian duct degenerate

Question 7

What is the Bidder’s organ and what species is it found in?

Answer 7

Found in Males toads

Functional of becoming a functional ovary

Question 8

The amount of fusion of the mullerian tubes determines the type of uterus and vagina, what kinds are there and who has them?

Answer 8

Duplex uterus - marsupials, rodents and bats

Bipartite (bicornate) uterus - horned uterus opening into one vagina

Simplex uterus - full fusion, in primates

Question 9

What are the female and male comparable external genitalia

Answer 9

Gentital tubercle
-penis or clitorus

Genital folds
-shaft or labia minora

Genital swellings

• fused: scrotum
• unfused: labia majora