Overview Male Repro - Checked and Complete

Question 1

What are 3 ways to determine sex?

Answer 1

1) Genetic (chromosomal)

**2) Gonadal **

3) Phenotypic (external genitalia)

Question 2

What gonadal hormone can sometimes work by providing positive feedback?

Answer 2

Estrogen

Question 3

Name the enzyme that converts Testosterone to Estradiol (and can work vice versa)

Answer 3

Aromotase

Question 4

What is unique about GnRH secretion during puberty?

Answer 4

GnRH (mostly LH and also FSH) secreted in circadian rhythym during puberty with peak while sleeping

Question 5

What contributes to phenotypic male sex (external genitalia formation)?

Answer 5

Anti-mullerian hormone

Adrogen

Question 6

Describe the currently suggested mechanism for the start of puberty.

Answer 6

Fat stores release leptin

Leptin increases sensitivity of GnRH neurons to Kisspeptin

Kisspeptin and stimulation of Kiss1neurons stimulates GnRH secretion

GnRH secretion leads to increase in FSH, LH

FSH and LH lead to testosterone and estradiol increases

Question 7

In order to start puberty, what is thought to become less sensitive to certain hormones?

Answer 7

Hypothalamus thought to become desensitized to negative feedback from gonadal hormones.

Question 8

Why are boys taller than girls?

Answer 8

Girls have their growth spurts occur earlier, which is followed by closing of gowth plates.

Question 9

What is the first sign of male puberty

Answer 9

Pubic hair and genital enlargement.