Q.In neuromuscular junction the substance that induces muscle contraction is:

Vaccination programmes combined with public awareness have been highly successful in controlling small pox, polio, diphtheria and tetanus -- unlike AIDS, amoebiasis or the common cold, none of which have an effective, widely-used preventive vaccine.

Vaccination is one of the most effective public-health tools for controlling infectious disease, and its success depends heavily on complementing it with awareness campaigns encouraging immunisation coverage. Small pox was declared globally eradicated in 1980 following an intensive worldwide vaccination campaign. Poliomyelitis has been brought to the verge of eradication in most countries, including India (certified polio-free), through the oral polio vaccine (OPV) delivered in mass immunisation drives (e.g., Pulse Polio programme) accompanied by extensive public awareness. Diphtheria and tetanus are both controlled through routine childhood immunisation (as part of the DPT vaccine) alongside awareness of the importance of completing the vaccination schedule. By contrast, amoebiasis is a protozoan disease controlled mainly through sanitation and hygiene (not a vaccine); AIDS currently has no effective pr …

Both calcium (bone mineral) and vitamin D (needed for calcium absorption) must be advised, so the answer is 'both'.

Bone strength comes from calcium phosphate deposited in the bone matrix. If dietary calcium is low, or if vitamin D is deficient, bones become soft, tender and brittle — the symptoms described. Calcium supplies the raw mineral, but calcium can only be absorbed efficiently from the intestine and deposited in bone when vitamin D is present. So advising only one of them is incomplete.

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Acetylcholine is the neurotransmitter released at the neuromuscular junction that triggers muscle contraction.

When a nerve impulse reaches the motor-nerve terminal, it releases acetylcholine into the synaptic cleft. Acetylcholine binds receptors on the muscle-fibre (sarcolemma), depolarises it, and sets off the events that lead to contraction.

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Iodine is the mineral needed for hormone (thyroxine) synthesis.

The thyroid hormones thyroxine (T4) and tri-iodothyronine (T3) contain iodine atoms in their structure. Without enough dietary iodine the thyroid cannot make these hormones properly, leading to disorders such as goitre. Hence iodine is directly involved in hormone synthesis.

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The dialyzer (dialysis machine) is called the artificial kidney.

In kidney failure, haemodialysis removes urea and other wastes from the blood by passing it across a semipermeable membrane in a machine. This machine/unit is the dialyzer, popularly termed the 'artificial kidney' because it performs the kidney's filtering job.

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The root-canal cavity is sealed with gutta-percha resin.

In root-canal treatment the dentist removes the infected/dead pulp, cleans and shapes the canal, then fills and seals it. The standard filling/sealing material is gutta-percha, a rubber-like resin obtained from certain trees, which is biologically inert and seals the canal well.

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The normal glomerular filtrate produced is about 125 ml per minute (GFR).

Glomerular filtration rate (GFR) is the volume of filtrate formed by both kidneys per minute. In a healthy adult this is about 125 ml/min, which works out to roughly 180 litres of filtrate per day (most of which is reabsorbed, so only ~1.5 litres of urine is excrete …

Vitamin K is needed to synthesise prothrombin (a blood-clotting factor).

Vitamin K acts as a cofactor in the liver for making prothrombin (and other clotting factors). Prothrombin is converted to thrombin during clotting, which turns fibrinogen into fibrin. Without vitamin K, prothrombin cannot be made properly and blood fails to clot normally.

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