Question.
Describe the structure and functions of nephron.
Describe the structure and functions of nephron.
solution:
The nephron is the functional unit of the kidney. A nephron consists of a twisted tubule closed at one end, open at the other with a network of associated blood vessels. Each kidney of man is formed of about one million nephrons.
Each nephron has a length of about 3 cm. It is differentiated into 4 regions having different anatomical features and different physiological roles.
Nephron : The 4 regions are :
(a) Bowman's capsule
(b) Proximal convoluted tubule (PCT)
(c) Loop of Henle
(d) Distal convoluted tubule (DCT)
(a)Bowman's capsule
It is a large double walled cup. It lies in the renal cortex. It contains a tuft of capillaries called glomerulus and the outer wall is continuous with the rest of the nephron. The space between the two walls of the Bowman's capsule is continuous with the lumen of the next part of the nephron. The bowman's capsule and the glomerulus together constitutes the renal corpuscle or malpighian body.
(b) PCT
It starts from the back of the Bowman's capsule and it is highly convoluted. It lies in the renal cortex. The wall consists of a single layer of cuboidal cells bearing a lot of microvilli on the surface.
(c)Loop of Henle
It is a U shaped segment of the nephron located in the renal medulla. It consists of two straight parallel limbs : a descending limb which is a continuation of the PCT and enters into the renal medulla and an ascending limb which re-enters the renal cortex and joins the DCT.
(d)DCT
It is greatly twisted like the PCT and lies in the renal cortex. The terminal relatively short part of the DCT is called the collecting tubule. It opens into the collecting duct.The collecting ducts receive the collecting tubules of several nephrons.
The nephron is the functional unit of the kidney. A nephron consists of a twisted tubule closed at one end, open at the other with a network of associated blood vessels. Each kidney of man is formed of about one million nephrons.
Each nephron has a length of about 3 cm. It is differentiated into 4 regions having different anatomical features and different physiological roles.
Nephron : The 4 regions are :
(a) Bowman's capsule
(b) Proximal convoluted tubule (PCT)
(c) Loop of Henle
(d) Distal convoluted tubule (DCT)
(a)Bowman's capsule
It is a large double walled cup. It lies in the renal cortex. It contains a tuft of capillaries called glomerulus and the outer wall is continuous with the rest of the nephron. The space between the two walls of the Bowman's capsule is continuous with the lumen of the next part of the nephron. The bowman's capsule and the glomerulus together constitutes the renal corpuscle or malpighian body.
(b) PCT
It starts from the back of the Bowman's capsule and it is highly convoluted. It lies in the renal cortex. The wall consists of a single layer of cuboidal cells bearing a lot of microvilli on the surface.
(c)Loop of Henle
It is a U shaped segment of the nephron located in the renal medulla. It consists of two straight parallel limbs : a descending limb which is a continuation of the PCT and enters into the renal medulla and an ascending limb which re-enters the renal cortex and joins the DCT.
(d)DCT
It is greatly twisted like the PCT and lies in the renal cortex. The terminal relatively short part of the DCT is called the collecting tubule. It opens into the collecting duct.The collecting ducts receive the collecting tubules of several nephrons.