Testosterone is a steroid hormone from the androgen group. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.
The adrenal cortex is devoted to the synthesis of corticosteroid hormones from cholesterol. Some cells belong to the hypothalamic-pituitary-adrenal axis and are the source of cortisol synthesis. Under normal unstressed conditions, the adrenal glands produce the equivalent of 35-40mg of cortisone acetate per day. Other cortical cells produce androgens such as testosterone, while some regulate water and electrolyte concentrations by secreting aldosterone. In contrast to the direct innervation of the medulla, the cortex is regulated by neuroendocrine hormones secreted by the pituitary gland and hypothalamus, as well as by the renin-angiotensin system.
Decreased production of testosterone:
* Chronic illness
* Delayed puberty
* Hypopituitarism
* Prolactinoma
* Testicular failure
Author: 
Testosterone is a steroid hormone from the androgen group. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.
The adrenal cortex is devoted to the synthesis of corticosteroid hormones from cholesterol. Some cells belong to the hypothalamic-pituitary-adrenal axis and are the source of cortisol synthesis. Under normal unstressed conditions, the adrenal glands produce the equivalent of 35-40mg of cortisone acetate per day. Other cortical cells produce androgens such as testosterone, while some regulate water and electrolyte concentrations by secreting aldosterone. In contrast to the direct innervation of the medulla, the cortex is regulated by neuroendocrine hormones secreted by the pituitary gland and hypothalamus, as well as by the renin-angiotensin system.
Decreased production of testosterone:
* Chronic illness
* Delayed puberty
* Hypopituitarism
* Prolactinoma
* Testicular failure