It is the Pituitary gland that regulates the secretion of sex hormones by the gonads (Testes and Ovary) in the human body (This means that the secretion of sex hormones takes place in Testes and Ovaries and their regulation in Pituitary).
The pituitary secretes gonadotropic hormones (or just gonadotropins) that regulate the secretion from sex glands or gonads in the human body. The two gonadotropic hormones are:
- 1. Follicle Stimulating Hormone (FSH)
FSH has a role to play in regulation of the production of sperms (in males) and egg production or ovulation (in females).
- 2. Luteinizing Hormone (LH):
The LH regulates the production of sex hormones namely testosterone (in males) and estrogen (in females).
During the onset of "puberty", the pituitary gland secretes gonadotropins (LH and FSH) that act on the male and female gonads and stimulate the production of sex hormones. This is why Testes and Ovaries become so active during and following puberty.
In males, sex hormones or the androgens (mainly testosterone) are produced by the male gonads called as testes. Testosterone is responsible for secondary sexual characteristics in the males like growth of moustache and beard, sperm production, change in the pitch of voice, etc.
The female gonads, the ovaries, secrete two sex hormones namely, estrogen and progestron, which are responsible for the development of secondary sexual characteristics in females like the onset of menstrual cycle, development of breasts, etc.
Thus, the production/secretion of sex hormones does not take place in the Pituitary gland, but in another set of glands of the endocrine system (ovaries and testes). The role of Pituitary gland is to just “regulate” or control the production of these sex hormones.
During puberty, the pituitary gland, a pea-sized gland located at the base of the brain, is responsible for regulating sex organ function. The female gonads are called ovaries and the male gonads are the testes. At puberty, a neurohormone called GnRH, is released by the hypothalmus in the brain and travels to the pituitary gland. A receptor called gonadotrophin-releasing hormone receptor, is activated, resulting in the activation of proteins needed to make luteinizing hormone(LH) and follicle stimulating hormone(FSH). These respond to various levels of GNRH pulses. Low-frequency leads to FSH release, and high frequency, leads to LH release. After the onset of puberty, in girls, the frequency of pulses will change during the menstrual cycle and a big surge of GNRH occurs before ovulation. In males, the GnRH is secreted at a constant frequency. Both the pituitary and hypothalmus must work properly in order for successful reproductive function to occur.