INTRODUCTION• The two adrenal glands, each of which weighs about 4 grams, lie at the superior poles of the two kidneys.• Each gland is composed two distinct parts: the inner medulla and the outer cortex.
ADRENAL CORTEX:• Secretes corticosteroids- mineralo-corticosteroids, gluco-corticosteroids and androgenic hormones.• Mineralo-corticosteroids- affect electrolytes of extracellular fluids: sodium and potassium.• Gluco-corticosteroids- increase the blood glucose level.• Androgenic hormones- exhibit the same effects as the male sex hormones.
ADRENAL MEDULLA:• Functionally related to the sympathetic nervous system.• Secretes Epinephrine and Nor-epinephrine• These hormones cause almost the same effects as direct stimulation of the sympathetic nerves in all parts of the body.
FUNCTIONS OF MINERALO-CORTICOIDS(ALDOSTERONE) :• Mineralocorticoid Deficiency Causes Severe Renal disorders like Sodium Chloride Wasting and Hyperkalemia.• Aldosterone Increases Renal Tubular Reabsorption of Sodium and Secretion of Potassium.• Aldosterone Stimulates Sodium and Potassium Transport in Sweat Glands, Salivary Glands, and Intestinal Epithelial Cells.
FUNCTIONS OF GLUCO-CORTICOIDS(CORTISOL):• Stimulate gluconeogenesis (formation of carbohydrate from proteins and some other substances) by the liver.• Cortisol also causes a moderate decrease in the rate of glucose utilization by most cells in the body.• Decreased protein synthesis and increased catabolism of protein already in the cells.• It promotes mobilization of fatty acids from adipose tissue.
• The cortisol has two basic anti-inflammatory effects: (1) It can block the early stages of the inflammationprocess before inflammation even begins. (2) If inflammation has already begun, it causes rapidresolution of the inflammation and increased rapidity of healing.• Cortisol reduces lymphocyte production and hence, suppresses immunity.• Cortisol Blocks the Inflammatory Response to Allergic Reactions.