Adrenal glands are located on the tops of the kidneys. They have external cortex and internal brain (medulla) layers (diagram 164). Adrenal cortex Th

Adrenal glands [Suprarenal]

Adrenal glands are located on the tops of the kidneys. They have external cortex and internal brain (medulla) layers (diagram 164).

Adrenal cortex

The cortical layer produces large amounts of hormones — corticosteroids, that are divided by physiological actions on mineralocorticoids, regulating water-salt metabolism; glucocorticoids, which affect the metabolism of proteins, carbohydrates and fats; sexual (androgens, estrogens), that play an important role in children's sexual development of the system, when the function of sex glands still insufficient. After puberty, their role becomes negligible.

Diagram 164. The structure of the adrenal glands: 1 — cortex; 2 — medulla

Corticosteroids development is controlled by adenohypophysis adrenocorticotropic hormone (ACTH). Taken from http://worldofschool.org

Adrenal medulla

Adrenal medulla is a part of sympathetic-adrenal system. It is formed by modified nerve cells of the sympathetic nervous system. These cells allow the secretion of the adrenaline and noradrenaline hormones, which is controlled by the autonomic nervous system and its supreme nerve center — the hypothalamus. The medulla secret contains 70-90% of adrenaline. These hormones provide urgent mobilization of the body resources, increase muscle performance and thereby contribute to the survival of the organism in emergency conditions, that is, under stress. Their effect is accompanied by increasing of arterial blood pressure, activation of the heart, increasing of blood glucose, increasing tone of skeletal muscles, and so on.

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Questions:
  • Identify the relationship of the adrenal glands structure and functions.