Male sex hormones

Question 1

Actions of testosterone: enlargement

Answer 1

Stimulates enlargement of testes and male accessory organs

Question 2

What is sexual development programmed by?

Answer 2

Genome

Question 3

Which gene determines sex?

Answer 3

23

Question 4

Is there a defined sex at 6 weeks of development?

Answer 4

No

Question 5

What does Gonad (cortex) form for females?

Answer 5

Ovary

Question 6

What does Gonad (cortex) form for males?

Answer 6

Regresses (Nothing)

Question 7

What does Gonad (medulla) form for females?

Answer 7

Regresses (Nothing)

Question 8

What does Gonad (medulla) form for males?

Answer 8

Testis

Question 9

What does Wolffian duct form for females?

Answer 9

Regresses (testosterone absent)

Question 10

What does Wolffian duct form for males?

Answer 10

Forms epididymis, vas deferens, and seminal vesicle (testosterone present).

Question 11

What does Mullerian duct form for females?

Answer 11

Becomes fallopian tube, uterus, cervix, and upper ½ of vagina (AMH absent)

Question 12

What does Mullerian duct form for males?

Answer 12

Regress (AMH present)

Question 13

What is the presence of the Y chromosome associated with?

Answer 13

SRY (sex determining region on Y chromosome) gene

Question 14

What happens to the cortex and medulla without the SRY gene present?

Answer 14

Cortex turns in ovaries and medulla disappears

Question 15

What is the SRY gene associated with?

Answer 15

Production and release of testi-determining SRY protein

Question 16

What does testi-determining SRY protein initiate?

Answer 16

Production of protein that will tun medulla into testis

Question 17

What is the consequence of medulla turning into testis?

Answer 17

The cortex of medulla disappears

Question 18

What are the two types of cells in the testis?

Answer 18

Leydig cells and Sertoli cells

Question 19

What do Sertoli cells secrete?

Answer 19

Anit-mullerian hormone

Question 20

what is the cause of secretion of Anit-mullerian hormone from Sertoli cells?

Answer 20

Regression of Mullerian duct

Question 21

What do Leydig cells secrete?

Answer 21

Testosterone

Question 22

What does secretion of testosterone hormone from Leydig cells control? (2)

Answer 22

Development of wolffian duct into accessory structures

Development of male external genitalia (via DHT)

Question 23

What is DHT?

Answer 23

Dihydrotestosterone is a male sex hormone. It is formed in the presence of enzyme 5α-reductase.

Question 24

What is testosterone?

Answer 24

A male sex hormone that is a potent androgen

Question 25

Where is testosterone synthesized?

Answer 25

Within the Leydig cells of testes (in males) and some from adrenal cortex (in both sexes).

Question 26

What is testosterone responsible for?

Answer 26

Development and maintenance of male secondary sexual characteristics.

Question 27

What stimulates enlargement of tastes and male accessary organs?

Answer 27

Testosterone

Question 28

What does testosterone bind to?

Answer 28

Androgen receptors

Question 29

Actions of testosterone: Stimulates development of male secondary sex characteristics (5)

Answer 29

1. Increased growth of body hair
2. Enlargement of the larynx and thickening of the vocal cords
3. Thickening of the skin
4. Muscle growth, widening of shoulders, narrowing of waist
5. Thickening and strengthening of bones

Question 30

Hormonal Control of Male Reproductive Functions:

Answer 30

Hormones are secreted by:

Question 31

Hormones are secreted by:

Answer 31

– Hypothalamus
– Anterior pituitary gland
– Testes

Question 32

Functions

Answer 32

– Development of sperm cells

– Development of secondary sex characteristics

Question 33

What is the rate at which sperm is produced in males?

Answer 33

At a constant rate with no limit.