Question

Correct sequence of events in the formation of urine

• A. Reabsorption → Tubular Secretion → Filtration
• B. Filtration → Tubular Secretion → Reabsorption
• C. Filtration → Reabsorption → Tubular Secretion
• D. Tubular Secretion → Micturition → Reabsorption

Hint:

The sequence of events in urine formation is critical for the body's regulation of water, electrolytes, and waste. Filtration occurs in the glomerulus, reabsorption mainly happens in the tubules, and tubular secretion removes excess substances into the urine.

Answer 1

The Correct Option is C

The formation of urine involves three main steps in the nephron of the kidney:

1. Filtration: The first step is the filtration of blood by the glomerulus. Water, salts, glucose, and urea are filtered out from the blood into the Bowman's capsule, forming the glomerular filtrate.
2. Reabsorption: As the filtrate passes through the renal tubules (proximal convoluted tubule, loop of Henle, and distal convoluted tubule), essential substances like glucose, water, and ions are reabsorbed back into the bloodstream.
3. Tubular Secretion: In this step, additional waste products such as hydrogen ions, potassium, and certain drugs are secreted from the blood into the renal tubules for excretion in the urine.

Thus, the correct sequence is Filtration → Reabsorption → Tubular Secretion, and Option (C) is the correct answer.