Urogenital

Question 1

How is the urogenital system structured?

Answer 1

i. kidney
ii. overies
iii. testicles
iv. efferent ducts
v. secondary sexual glands

Question 2

Why are the urinary and reproductive system connected?

Answer 2

Even if in vertrebrates the urinary and reproductive systems are connected, they have very different functions: originally, the testis lacked of the efferent duct, but the kidney had one (archinephric duct).

Question 3

How humans can have two kidneys when they have three of them during embryonic development?

Answer 3

During development, the kidney assume various forms and decrease of number:

• initially, it is a set of tubules (nephridia)
• 3 kidneys during development:
  i. pronephros:
  - small, no ED
  - non functional in humans
  - neck
  ii. mesonephros
  - abdomen
  - archinephric duct
  - functional in fetus
  iii. metanephros
  - ureter
  - adults

Question 4

How do the male and female urogenital system develop?

Answer 4

The fetus is unisex: it has two ED (wolffian and mullerian ducts) which, depending on the stimulation of hormones, will develop in one sex-specific system:

• if at week 6 SRY is activated = male
  
  • WD maintained (archinephric duct)
  • MD degraded
• if at week 6 SRY is not activated = female
  
  • WD degraded
  • MD maintained (paramesonephric duct)

Question 5

What are the membranes that are present in the womb of mammals?

Answer 5

1. Chroion
2. Amnion
3. Yolk sac
4. Allantois

Question 6

What is the urachus?

Answer 6

The urachus is a tube that connect the bladder to the umbilical cord. It will degenerate in a ligament (co-opted)

Question 7

Why do testicles descent?

Answer 7

1. Sperm cells develops better at lower temperature
2. Masculinity
3. Prevent damage