1. Adrenal Medulla. Prof. K. Sivapalan

2. 08-01-14Adrenal Medulla.2 Strtucture. Location- centre of adrenal gland and paravertibral ganglia. Blood supply - cortical- sinusoids into medulla and some arterioles. Nerve supply-pre ganglionic sympathetics.

3. 08-01-14Adrenal Medulla.3 Synthesis of Catecholamines.

4. 08-01-14Adrenal Medulla.4 Secretion. Synthesis- nor adrenalin → adrenalin: in adrenal medulla and brain only. Steroids from cortex facilitate synthesis. Half life of catecholamines- 2 minutes. 80% adrenalin 20% nor adrenalin. Receptors- detail study under Autonomic Nervous System. Adrenalin- α and β receptors Noradrenalin- β receptors only.

5. 08-01-14Adrenal Medulla.5 Effects of Catecholamines glycogenolysis- liver,muscle. gluconeogenisis. lipolysis- adipose tissue. potassium- release increased in liver [initial rise], entry increased in muscle [prolonged fall]. increases- metabolic rate, calorie genesis, alertness, anxiety, fear. reduces- proteolysis in muscle, insulin secretion.

6. 08-01-14Adrenal Medulla.6 Differences.

7. 08-01-14Adrenal Medulla.7 Regulation of Secretion. Sympathetic activity. Sleep:- very low. Rest:- less Increased in: hypoxia, asphyxia, acidaemia, hypoglycaemia, hypothermia, hypotension, haemorrhage, exercise, fear, anger, pain, sexual excitement. Stress:- maximum.

8. 08-01-14Adrenal Medulla.8 Hypo function Not known. Experimental animals- cold intolerance.

9. 08-01-14Adrenal Medulla.9 Hyperfunction - Pheochromocytoma hypertension in bouts. sweating. paroxysmal attacks of blanching or flushing. tachycardia and palpitations. headache anorexia, weight loss. psychic changes decreased GIT motility. increased metabolism. postural hypotension. Mimicking other conditions- Insulin- increased fasting sugar, abnormal GTT. Hysteria- psychosis, tremors, increased respiration. Hirshprung's disease- constipation. Thyrotoxicosis- increased BMR, respiration, oxygen consumption, weight loss, psychosis, tremors.