Biology · Excretory Products and Their Elimination · NEET
No, but they are linked. Uremia is the build-up of urea in the blood because the kidneys are not filtering it out. NCERT says malfunctioning kidneys cause uremia, which is highly harmful and MAY lead to kidney failure. So uremia is the warning sign; renal failure is the kidneys stopping their work. Hemodialysis is used to remove the excess urea in uremic patients.
To lower the chance of rejection by the patient's immune system. NCERT states a functioning kidney is taken from a donor, preferably a close relative, to minimise chances of rejection by the host's immune system. A close relative shares more similar tissue markers, so the body is less likely to attack the new kidney. This is why matching matters more than just having a spare kidney.
No. The artificial kidney only filters the blood — it removes urea and extra ions using the dialysing fluid (same composition as plasma except the nitrogenous wastes). But it cannot do the kidney's hormone jobs: activating vitamin D (needed to absorb calcium from the gut) and making erythropoietin (needed for RBC production). So long-term dialysis patients can have reduced calcium absorption and reduced RBC production. This exact idea was tested in NEET 2019.
An anticoagulant called heparin is added when the blood is drained from the artery into the dialysing unit, so the blood does not clot inside the machine. After the blood is cleaned, anti-heparin is added before pumping it back into a vein, so normal clotting is restored in the body. The dialysing fluid has the same make-up as plasma but with no nitrogenous wastes, so wastes move out by the concentration gradient.
For a lasting fix, yes. NCERT calls kidney transplantation the ultimate method in correcting acute renal failure. Dialysis is a repeated, ongoing filtering that keeps a uremic patient alive but does not restore hormone functions. A successful transplant gives a working kidney that both filters AND makes hormones. Modern clinical procedures have raised the success rate of this complicated technique.
Use of an artificial kidney during hemodialysis may result in: (a) Nitrogenous waste build-up in the body (b) Non-elimination of excess potassium ions (c) Reduced absorption of calcium ions from gastro-intestinal tract (d) Reduced RBC production. Which of the following options is the most appropriate?
Match List-I with List-II. List-I: A. Emphysema, B. Angina Pectoris, C. Glomerulo-nephritis, D. Tetany. List-II: I. Rapid spasms in muscle due to low Ca++ in body fluid, II. Damaged alveolar walls and decreased respiratory surface, III. Acute chest pain when not enough oxygen is reaching to heart muscle, IV. Inflammation of glomeruli of kidney.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Uremia is the build-up of urea in the blood because the kidneys are not filtering properly. NCERT says it is highly harmful and may lead to kidney failure.
It is the dialysing unit used in hemodialysis. Blood from an artery is pumped through a coiled cellophane tube surrounded by dialysing fluid, and nitrogenous wastes move out to clean the blood.
So that only wastes leave the blood. Since wastes are absent in the fluid, they move out along the concentration gradient, while useful substances (also present in the fluid) are not lost.
Kidney transplantation. NCERT calls it the ultimate method of correction; a working kidney is taken from a donor, preferably a close relative, to reduce rejection.
Because dialysis only filters and cannot do the kidney's hormone roles — activating vitamin D (calcium absorption) and making erythropoietin (RBC production). This was the key to NEET 2019.
