Home › Histology › Endocrine Function of the Gonads

Endocrine Function of the Gonads

For medical students2 min readUpdated 2026-10-10

The endocrine function of the gonads involves the cyclic and continuous production of sex hormones that regulate somatic development and reproductive capacity. In males, this role is performed by the testes, which synthesize androgens; in females, it is performed by the ovaries, which produce estrogens and progestins depending on the phase of the cycle.

Main androgensTestosterone and its active derivative, dihydrotestosterone.

Fetal protectionProgesterone blocks myometrial sensitivity to oxytocin.

Estrogen targetsUterus, developing mammary gland ducts, and the anterior pituitary.

AnabolismAndrogens stimulate protein synthesis in muscles and other tissues.

Testicular Hormones: Androgens

The endocrine activity of the male gonads is primarily associated with the production of androgens. The principal representatives of this group are testosterone and its active metabolites, particularly dihydrotestosterone. These hormones exert comprehensive effects throughout the male body, extending far beyond the reproductive system.

The key effects of androgens can be divided into two major categories:

Metabolic effects. Male sex hormones actively regulate metabolism. They trigger lipolysis—the mobilization of fat from tissue stores. Simultaneously, they exhibit a powerful anabolic effect, which involves stimulating protein synthesis in skeletal muscle and other tissues.
Morphogenetic effects. Testosterone is responsible for the development and maturation of secondary male sex characteristics.

Ovarian Hormones: General Principles and Estrogens

The endocrine function of the female gonads is characterized by strict periodicity. Hormone production is subordinated to the menstrual cycle, and their actions are directed specifically at target organs: the uterus, mammary glands, and pituitary gland.

The first group of female hormones consists of estrogens (including estradiol and its metabolites). Their primary source is maturing and atretic ovarian follicles. Globally, estrogens are responsible for the development of secondary female sex characteristics, though their cyclic activity has distinct target sites:

Uterus. Following menstruation, estrogens trigger active regeneration and repair of the endometrium.
Mammary glands. Estradiol stimulates the growth and branching of the lactiferous ducts.
Pituitary gland. Operating via negative feedback, high estrogen levels inhibit further production of follicle-stimulating hormone (FSH).

Progestins: Hormones of the Corpus Luteum

The second phase of the cycle is controlled by progestins, the chief representative being progesterone. This hormone is actively produced during the postovulatory (luteal) phase, with the newly formed corpus luteum serving as its primary source. The biological role of progesterone is to prepare the female body for potential pregnancy.

The effects of progesterone on target organs include:

Uterus. Under the influence of progesterone, the endometrium becomes edematous, and uterine glands begin active mucus secretion. A crucial factor in maintaining pregnancy is progesterone's ability to decrease the sensitivity of the myometrium (the uterine smooth muscle layer) to oxytocin, thereby preventing premature uterine contractions.
Mammary glands. In contrast to estrogens, which stimulate ductal growth, progesterone induces the development of terminal secretory units (alveoli).
Pituitary gland. Through negative feedback, progesterone suppresses the secretion of luteinizing hormone (LH) by the anterior pituitary.

Mnemonic

Estrogens build "roads" (mammary ducts) and the "foundation" (endometrial regeneration). Progesterone prepares "rooms" (alveoli) and a "soft bed" (endometrial swelling, blockade of contractions).

Frequently asked questions

Which testicular cells synthesize testosterone?

Testosterone in the testes is synthesized by Leydig cells (interstitial endocrine cells).

They develop from mesenchyme and are located in the interstitial tissue of the organ. The production of testosterone by these cells is directly stimulated by luteinizing hormone (LH) released from the anterior pituitary. The secreted hormone enters the blood and lymph and also acts locally on spermatogenic cells and Sertoli cells, ensuring the development of male sex characteristics and supporting spermatogenesis.

Which ovarian follicle cells produce estrogens?

Estrogens in the growing follicle are produced by follicular cells (granulosa cells) with the participation of theca cells.

Synthesis proceeds via cooperation between two cell types:

Theca cells synthesize androgens under the influence of LH: cholesterol → progesterone → testosterone; testosterone then diffuses into adjacent follicular cells.
Follicular cells, under the influence of FSH, take up testosterone and convert it to estradiol via aromatization of androgens.

The resulting estradiol accumulates in the follicular antrum and is secreted into the blood.

From which ovarian structures does the corpus luteum form?

The corpus luteum forms from the ovulated follicle through the luteinization of granulosa cells.

Following ovulation, driven by LH, granulosa cells undergo luteinization: their cytoplasm enlarges and lipid droplets accumulate. As a result, the corpus luteum forms as a transient, hormonally active structure that secretes progesterone.

Where are estrogens synthesized?

They are produced in maturing and atretic ovarian follicles.

Which hormone is responsible for the growth of alveoli in the mammary gland?

Progesterone is responsible for the development of terminal secretory units (alveoli).

What is the feedback mechanism for estrogens?

High levels of estrogens inhibit the production of follicle-stimulating hormone (FSH) in the pituitary gland.

Why is progesterone called the hormone of pregnancy?

It prepares the endometrium for implantation and decreases myometrial sensitivity to oxytocin, preventing miscarriage.

Go deeper

Cellular composition of maturing and atretic follicles
Structure and developmental stages of the corpus luteum
Negative feedback mechanisms in the hypothalamo-pituitary-gonadal axis
Histological structure of the endometrium and myometrium
Synthesis of testosterone and its derivatives