9. Gonadal hormones

Question 1

Briefly describe the mechanism of LH and FSH.

Answer 1

Hypothalamus -> GnRH -> AP -> FSH/LH -> ovaries/testes.

FSH acts on granulosa cells to produce oestrogen and sertoli cells to stimulate spermatogenesis.

LH acts on theca cells to produce androgens or leydig cells to produce testosterone.

Question 2

What cells does FSH act on?

Answer 2

• In the ovaries: granulosa cells.
• In the testes: sertoli cells.

Question 3

What cells does LH act on?

Answer 3

• In the ovaries: theca cells
• In the testes: leydig cells.

Question 4

What is the function of theca cells?

Answer 4

Theca cells are stimulated by LH to produce androgens that diffuse into granulosa cells to be converted into oestrogen.

Question 5

What is the function of granulosa cells?

Answer 5

Granulosa cells are stimulated by FSH to convert androgens into oestrogen using aromatase.

Question 6

What is the function of sertoli cells?

Answer 6

Sertoli cells produce MIF (mullerian inhibiting factor) and inhibin and activin which acts on the pituitary gland to regulate FSH.

Question 7

What is the function of leydig cells?

Answer 7

Leydig cells are stimulated by LH to produce testosterone.