Biology · Human Health and Diseases · NEET
Nicotine does not act on the heart directly first. It stimulates the adrenal gland to release adrenaline (epinephrine) and nor-adrenaline (nor-epinephrine) into the blood. These two hormones raise blood pressure and increase the heart rate. This is the exact NCERT line and is a common NEET match-the-column point.
Because nicotine triggers the adrenal gland to pour adrenaline and nor-adrenaline (catecholamines) into the blood. These catecholamines make the heart beat faster and squeeze blood vessels, so blood pressure goes up. For NEET, link nicotine -> adrenal gland -> catecholamines -> high BP and fast heart.
The adrenal gland. Nicotine stimulates the adrenal gland to release adrenaline and nor-adrenaline (together called catecholamines) into blood circulation. NEET 2026 tested this exact fact in a match-the-column question.
Nicotine acts as a stimulant type of drug because it activates the adrenal gland and speeds up the heart and blood pressure. Do not confuse it with heroin, which is a depressant that slows down body functions. Mixing these up is the main NEET trap in drug match questions.
Smoking increases carbon monoxide (CO) in the blood. CO binds haemoglobin and reduces the amount of haem-bound oxygen. This causes oxygen deficiency in the body. So a smoker's tissues get less oxygen even though breathing looks normal.
NCERT lists cancer of the lung, urinary bladder and throat, plus bronchitis, emphysema, coronary heart disease and gastric ulcer. Tobacco chewing (not smoking) is linked to cancer of the oral cavity. Emphysema is the chronic lung disorder chiefly caused by cigarette smoking.
Smoking is linked to cancer of the lung, urinary bladder and throat. Tobacco chewing is linked to cancer of the oral cavity (mouth). Both deliver nicotine, but the cancer site differs by how tobacco is used.
Match List I with List II: List I (Drug): A. Nicotine B. Morphine C. Heroin D. Cocaine List II (Effect): I. Causes sense of euphoria and increased energy II. Stimulates adrenal gland to release catecholamines into blood circulation III. Effective sedative and painkiller IV. A depressant; slows down body function
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Yes. NCERT states tobacco contains many chemicals including nicotine, which is an alkaloid. It is the active drug that causes tobacco addiction.
Emphysema is a chronic disorder in which alveolar walls are damaged, so the respiratory surface for gas exchange decreases. NCERT names cigarette smoking as a major cause. It is a frequently asked one-line NEET fact.
Yes. NCERT lists coronary heart disease among the conditions linked to smoking. Nicotine-driven high blood pressure and fast heart rate plus reduced oxygen strain the heart and blood vessels.
NCERT notes tobacco has been used by human beings for more than 400 years. It is smoked, chewed, or used as a snuff.
Smoking raises carbon monoxide (CO) in the blood. CO reduces the amount of haem-bound oxygen carried by haemoglobin, so tissues receive less oxygen and the body faces oxygen deficiency.
