Biology · Chemical Coordination and Integration · NEET
The cortex is the OUTER layer and the medulla is the CENTRAL (inner) part. NCERT says: 'The centrally located tissue is called the adrenal medulla, and outside this lies the adrenal cortex.' Easy trick: 'cortex' sounds like a coat, and a coat goes on the outside. Many students flip this and lose marks in matching questions, so lock it: Cortex = Coat = Outside; Medulla = Middle.
The adrenal MEDULLA (inner part) makes adrenaline (epinephrine) and noradrenaline (norepinephrine), together called catecholamines. The adrenal CORTEX (outer part) makes cortisol and aldosterone, together called corticoids. So all the 'fight or flight' fast hormones are from the medulla, and the slow steroid hormones are from the cortex.
Adrenal cortex hormones (corticoids like cortisol and aldosterone) are STEROID hormones — they are made from cholesterol. Adrenal medulla hormones (adrenaline, noradrenaline) are amino-acid derived (from the amino acid tyrosine), not steroids. This is a common NEET trap: 'Which is NOT a steroid?' — glucagon and adrenaline are not steroids, but cortisol IS.
Both are made by the adrenal cortex. Glucocorticoids (mainly cortisol) control glucose — they stimulate gluconeogenesis, lipolysis, proteolysis, and give anti-inflammatory action while suppressing the immune response. Mineralocorticoids (mainly aldosterone) control minerals — aldosterone acts on renal tubules to reabsorb Na+ and water and excrete K+, so it maintains electrolytes and blood pressure.
Addison's disease is caused by UNDERPRODUCTION of hormones by the adrenal CORTEX. It alters carbohydrate metabolism and causes acute weakness and fatigue. Note: it is the cortex, not the medulla. Cushing's syndrome, on the other hand, is EXCESS cortisol from the cortex (moon face, hyperglycemia).
Yes. Adrenal MEDULLARY hormones (adrenaline/noradrenaline) increase heart beat, strength of heart contraction, and cardiac output — this is the fast emergency response. NCERT also notes glucocorticoids (from the cortex) help maintain the cardio-vascular system. So both parts touch the heart, but the fast, direct effect on heart rate is from the medulla.
Consider the following statements regarding function of adrenal medullary hormones: A. It causes pupillary constriction B. It is a hyperglycemic hormone C. It causes piloerection D. It increases strength of heart contraction Choose the correct answer from the options given below:
Match List I with List II: List-I: A. Cortisol B. Aldosterone C. Cholecystokinin D. Progesterone List-II: I. Stimulates the formation of alveoli in mammary glands II. Produces anti-inflammatory reactions III. Stimulates reabsorption of Na+ and water from renal tubule IV. Stimulates secretion of pancreatic enzymes and bile juice
Match List I with List II. List I: A. Exophthalmic goiter B. Acromegaly C. Cushing's syndrome D. Cretinism List II: I. Excess secretion of cortisol, moon face & hyperglycemia II. Hypo-secretion of thyroid hormone and stunted growth III. Excess thyroid hormone (over-active thyroid) IV. Excess growth hormone in adults
Try the real previous-year questions from this chapter — each with the answer and a full solution.
There is one pair of adrenal glands, meaning two glands in total — one placed on top of each kidney. That is why they were once called 'suprarenal' glands (supra = above, renal = kidney).
The two parts are the outer adrenal cortex and the inner adrenal medulla. The cortex secretes corticoids (steroid hormones); the medulla secretes catecholamines (adrenaline and noradrenaline).
They are secreted quickly during stress and emergencies, so NCERT calls them 'emergency hormones' or 'hormones of Fight or Flight'. They increase alertness, pupil dilation, piloerection, sweating, heart rate, strength of heart contraction, and rate of respiration.
Cortisol is a steroid hormone, made from cholesterol in the adrenal cortex. All corticoids (cortisol, aldosterone) are steroids, while medullary hormones like adrenaline are amino-acid derived.
Aldosterone, the main mineralocorticoid from the adrenal cortex, acts on the renal tubules to reabsorb Na+ and water and excrete K+ and phosphate. This maintains electrolytes, body fluid volume, and blood pressure.
