What is a uriniferous tubule? How does it function? [3 MARKS]

Uriniferous tubule: 1 Mark
Function: 2 Marks

The kidney is composed of numerous complex minute structures called nephrons or uriniferous tubules. There are nearly two million nephrons in the two kidneys. These are the structural as well as functional units of kidneys. These are composed of renal corpuscles and renal tubules.

Nephrons and collection ducts perform 3 basic processes:
- Glomerular filtration is the first function of the nephron. A portion of the blood plasma is filtered in the kidney.
- Tubular reabsorption is the second function of the nephrons and collecting duct. Water and useful substances are reabsorbed into the blood.
- Tubular secretion is the third function of nephrons. Wastes are removed from the blood and passed into urine.