Adrenal cortex secretes cortical steroids are that are grouped into three catagories : mineralocorticoids, glucocorticoids and gonadocorticoids.
(i) Mineralocorticoids : (a) These hormones are j secreted by the cells of zona glomerulosa or adrenal cortex. (b) Aldosterone (salt-retaining hormone) j is the principal mineralocorticoid in humans. Its main function is to regulate the sodium content of the body, © It is secreted when the sodium level is low. (d) It acts on the kidneys to cause more sodium to be returned to the blood and more potassium to be excreted, (e) As the sodium concentration in the blood increases, water flows into it by osmosis, so the blood’volume aslo increases, (f) The effect of aldosterone is to increase both sodium and water in i the blood.
(ii) Glucocorticoids : (a) They effect carbohydrate metabolism, however, they also affect
, the metabolism of proteins and fats, (b) Glucocorticoids include three main hormones : cortisol, corticosterone and cortisone, © Cortisol stimulates the liver to synthesize carbohydrates from non-carbohydrates sources such as amino acids and glycerol. Thus increases level of glucose in the j blood, (d) Cortisol also stimulates the degradation of proteins within cells and amino acids in the blood, (e) A third effect of cortisol is to stimulate the i breakdown of fats in adipose tissue and release fatty acids into the blood. Cortisol is anti-inflammatory.
(f) Cortisol is also “immunosuppressive”,
(g) It suppresses synthesis of antibodies by
inhibiting the production of lymphocytes in the [ lymphoid tissues, (h) This hormone increases RBC count, but decrease the WBC count of blood.
Gonadocorticoids : (a) They are also called sex hormones of adrenal glands, (b) These male sex hormones are called androgens which are important in the development of a male foetus, © A male foetus develops normal male characteristics only if the foetal gonads and adrenal glands produce sufficient quantities of androgens, (d) Androgens stimulate the development of male secondary sexual characters like distribution of body hair, (f) Female sex hormones secreted by the adrenal cortex are oestrogens which maintain the development of female secondary sexual characters.