adrenal

• adrenal gland is meso-ectodermal in origin
• adrenal medulla is ectodermal and secretes adrenaline and nor adrenaline
• adrenaline and noradrenaline are commonly called

  catecholamines
• the adrenal cortex has three layers, the outer zona glomerulosa, middle zona fasciculata and inner zona reticularis
• zona fasciculata secretes glucocorticoids
• cortisol is the main glucocorticoid and stimulates gluconeogenesis, lipolysis, proteolysis and inhibits cellular uptake and utilization of amino acids
• cortisol also maintains the cardio-vascular system and kidney functions
• cortisol produces anti-inflammatory reactions and suppresses immune response
• cortisol also stimulates RBC formation
• zona glomerulosa secretes mineralocorticoids that regulate balance of water and electrolytes in the body
• aldosterone is the major mineralocorticoid
• aldosterone increases Na+ and water reabsorption by distal tubules and collecting ducts of nephrons, and promotes K+ excretion
• zona reticularis secretes small amounts of androgenic corticoids
• underproduction of hormones by the adrenal cortex alters carbohydrate metabolism causing acute weakness and fatigue leading to Addison's disease
• overproduction of hormones by the adrenal cortex causes Cushing's syndrome