Question

Give the full form of FSH. Name the gland that secretes it. How does it differ in function in males and females? What stops its secretion in females?

Answer 1

Hint: FSH is a trophic hormone and its release is controlled by GnRH. It favors the rupture of the Graafian follicle. It is inhibited by progesterone.

Complete answer:
- FSH stands for follicle-stimulating hormone. It is secreted by the anterior pituitary. It stimulates or helps in gametogenesis.

- The anterior portion of the pituitary gland contains the hypophyseal portal system. It’s a vascular network. The anterior pituitary secretes hormone in response to releasing hormone from the hypothalamus. Gonadotropin Releasing Hormone (GnRH) facilitates the release of FSH and LH. In females, FSH helps in the development of ovarian follicles and thus the secretion of estrogen. In males, it helps in spermatogenesis, thus sperm development.

- Estradiol and inhibin are responsible for suppressing FSH secretion in females.

- Estradiol is a form of estrogen which is a female sex hormone. It acts on the pituitary to selectively inhibit FSH secretion.

- Inhibin is a glycoprotein that is produced in gonads (theca and granulosa cells of the ovary and Sertoli cells of testis), pituitary glands, placenta, and other organs. Inhibin suppresses FSH secretion.

- After ovulation, the ruptured Grafiaan follicle forms the corpus luteum which secretes progesterone. The high progesterone levels inhibit FSH secretion.

Note: FSH is secreted in both males and females, but its inhibition is controlled in different ways in both males and females. In females, inhibins, progesterone, Estradiol brings about suppression of FSH whereas high levels of testosterone in males decreases FSH secretion.