The following 6 (Six) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the correct answer using the code given below : Statement I : Too much salt content in diet could be one of the reasons for kidney failure. Statement II : High salt may cause high blood pressure.
- (a)Both the statements are individually true and Statement II is the correct explanation of Statement I
- (b)Both the statements are individually true but Statement II is not the correct explanation of Statement I
- (c)Statement I is true but Statement II is false
- (d)Statement I is false but Statement II is true
Correct — A, both statements are individually true and Statement II is the correct explanation of Statement I. Note first how carefully the paper hedges both statements — 'could be one of the reasons' and 'may cause' — so neither claims that salt alone destroys kidneys. Statement II is true: sodium is the chief osmotically active ion outside the body's cells, so a heavy salt intake makes the body hold on to water, which raises the volume of circulating blood and with it the pressure in the arteries. Statement I is true as well, and Statement II is exactly why. The kidney's filtering units are tufts of extremely fine capillaries, and they work under pressure; when that pressure stays high for years the delicate vessel walls thicken and scar, filtration falls, and chronic kidney disease follows. Long-standing high blood pressure and diabetes are the two commonest routes to kidney failure worldwide. Salt therefore reaches the kidney through blood pressure, so the second statement supplies the mechanism behind the first and option (a) is right.
- (b)Both the statements are individually true but Statement II is not the correct explanation of Statement I — This would be right only if raised blood pressure were an unrelated side-effect of salt. It is the connecting step. Remove hypertension from the chain and the ordinary dietary link between salt and kidney damage largely disappears.
- (c)Statement I is true but Statement II is false — The salt and blood pressure link is one of the best-established findings in public-health nutrition, and it is why the World Health Organization advises adults to keep salt below about five grams a day.
- (d)Statement I is false but Statement II is true — Statement I is deliberately modest — it says excess salt 'could be one of the reasons' for kidney failure, which is uncontroversial. Rejecting it would mean denying that sustained hypertension harms the kidney at all.
Each kidney holds about a million nephrons, and every nephron begins with a glomerulus — a knot of capillaries inside Bowman's capsule where blood is filtered under pressure. Sodium governs how much water the body retains, so dietary salt influences blood volume and therefore arterial pressure. The relationship runs both ways: the kidney itself helps set blood pressure by releasing the enzyme renin, which starts the cascade that constricts vessels and conserves sodium.
The item is a straightforward cause-and-effect pair, and the way to be sure is to lay the chain out and see whether Statement II sits inside it: more salt, more retained water, higher blood volume, higher pressure, damaged glomerular capillaries, failing kidneys. Statement II is the fourth link, so it explains Statement I. Contrast this with the ozone and Rome pairs elsewhere in the same block, where the two statements sit side by side without any such chain — that contrast is the whole point of asking six of these together.
- Sodium is the main osmotically active ion in extracellular fluid, so a high salt intake makes the body retain water and raises blood volume.
- The World Health Organization recommends that adults consume less than about five grams of salt a day.
- Blood is filtered in the glomerulus, a capillary tuft enclosed by Bowman's capsule at the head of each nephron.
- High blood pressure and diabetes are the two leading causes of chronic kidney disease worldwide.
- The kidney also regulates blood pressure itself, by secreting renin when perfusion falls.
- Marking option (b) out of caution whenever a health claim looks hedged — the hedging in the stem does not weaken the causal link.
- Forgetting that the kidney is both a victim of high blood pressure and one of its regulators.
Human physiology in NDA GAT favours the kidney, the heart and the eye, and often frames them as cause-and-effect pairs, so learn each organ with the chain of events attached.
With reference to the work of human kidney, consider the following statements: 1. After the waste is removed in the kidney, the cleaner blood is sent back through renal artery. 2. From Bowman’s capsule, the filtered liquid passes through tiny tubes where much of the glucose is reabsorbed and sent back to the blood in the renal vein. Which of these statements is/are correct?
- (a) Only 1
- (b) Only 2
- (c) Both 1 and 2
- (d) Neither 1 nor 2
Answer(b) Only 2
Walks through the filtering machinery that high blood pressure damages, from Bowman's capsule to the renal vein — worth solving alongside this item to see what is actually at risk.
Kidney secretes an enzyme, which changes plasma protein angiotensinogen into angiotensin. The enzyme is
- (a) Renin
- (b) Nitrogenase
- (c) Hydrolase
- (d) Mono-oxygenase
Answer(a) Renin
The return leg of the same relationship — here the kidney is raising blood pressure rather than suffering from it, which is why the two are so tightly bound in medicine.
- practice — not a real PYQ
Filtration of blood in the kidney takes place in the
- (a)collecting duct
- (b)glomerulus enclosed by Bowman's capsule
- (c)loop of Henle
- (d)renal pelvis
Answer(b) glomerulus enclosed by Bowman's capsule — the capillary tuft at the head of each nephron.
- practice — not a real PYQ
A high intake of common salt raises blood pressure chiefly because sodium
- (a)hardens the walls of the arteries directly
- (b)causes the body to retain water and so increases blood volume
- (c)increases the number of red blood cells
- (d)blocks the release of renin from the kidney
Answer(b) causes the body to retain water and so increases blood volume — more fluid in the same vessels means higher pressure.