Question

Write short notes on Nephron.

Answer 1

Hint: Nephrons are the structural and functional unit of the kidney. It is the complex microscopic structure whose main function is to produce urine and eliminate excess molecules and ions from the blood.

Complete Answer:
The excretory system of human beings is made up of long tubular structures called the nephrons.
Let's discuss the structure of nephron-

- Bowman ’s capsule: It is a cup like structure whose main function is ultrafiltration.
Glomerulus gets blood from afferent arterioles. It consists of a small tuft of capillaries through which blood flows in high pressure.
- The Loop of Henle is a hair-pin like structure. It comprises a thin ascending limb and thick descending limb. The fluid filtered through glomerulus reaches the collecting duct through the loop. Re-absorption of useful substances, especially water is the main function of this loop.
- Distal convoluted tubules have many mitochondria present in the cell lining. They produce energy required for active transport. It helps in reabsorption of calcium ions.
- Proximal convoluted tubule: Here salt water and organic solutes like glucose and amino acids are filtered.
- Collecting tubules is the last part of the tubules before entering the collecting duct. Re-absorption of water takes place in this tubule.

Function of Nephron:
- It regulates the ionic and molecular substances in blood.
- It maintains the homeostasis of blood by maintaining the blood pressure.
- It excretes the harmful substances and reabsorbs the useful ones.

Note: The kidney of a healthy adult has around 1 to 1.5 million nephrons per kidney. Kidneys detoxify our body. If the toxic substances get accumulated in our body, the function of nephrons is disturbed. This can lead to dialysis, kidney failure or even death. A person can survive with a single kidney as well.