This reaction causes air passages to dilate to provide the muscles with the oxygen they need to either fight danger or flee. What is the Function of Adrenaline?Īdrenaline triggers the body's fight-or-flight response. Within a couple of minutes during a stressful situation, adrenaline is quickly released into the blood, sending impulses to organs to create a specific response. It increases blood flow to the skeletal muscles there by increases the metabolic rate of skeletal muscles, cardiac muscles and nervous tissue.Adrenaline is produced in the medulla in the adrenal glands as well as some of the central nervous system's neurons. It stimulates the smooth muscles of cutaneous and visceral arteries to decrease blood flow. During emergency it increases heart beat rate and blood pressure. The adrenal medulla secretes the hormones adrenalin and noradrenalin and are referred as '3F hormone' (fight, flight and fright hormone), Adrenalin increases liver glycogen breakdown into glucose and increases the release of fatty acids from fat cells. Adrenal androgen plays a role in hair growth in the axial region, pubis and face during puberty. Aldosterone stimulates the reabsorption of sodium and water and eliminates potassium and phosphate ions through excretion, thus it helps in maintainting electrolytes, osmotic pressure and blood pressure.

Mineralocorticoids regulates water and electrolyte balance of our body. It is also known as stress combat hormone. It produces anti-inflammatory reactions and suppresses the immune response. Cortisol is a glucocorticoid invloved in maintaining cardio vascular and kidney functions. Glucocorticoids stimulate gluconeogenesis, lipolysis and proteolysis (the life saving avtivity).

Both adrenalin and nor adrenalin are catecholamines. Adrenalin (epinephrine) and noradrenalin (nor epinephrine) are the two hormones secreted by the adrenal medulla. Zona reticularis, an inner zone of adrenal cortex constitute about 10% of adrenal cortex and secretes the adrenal androgen, trace amount of oestrogen and glucocorticoids.Īdrenal medulla: It is the central part of adrenal gland and is composed of ovoid and columnar cells, which are found around the network of blood capillaries. Zona fasciculata, the middle widest layer constitutes about 75% of adrenal cortex and secretes glucocorticoids such as cortisol layer constitutes about 75% of adrenal cortex and secretes glucocorticoids such as cortisol, corticosterone and trace amounts of adrenal androgen and oestrogen. Zona glomerulosa an outer thin layer constitutes about 15% of adrenal cortex, and secretes mineralocorticoids. Histologically the adrenal cortex has three distinct zones, zona glomerulosa, zona fasciculata and zona reticularis. Anatomically the outer region is the cortex and the inner region is the medulla. A pair of adrenal glands are located at the anterior end of the kidneys, hence also called suprarenal glands.

Hormones secreted by adrenal medulla