CBSE Class 10 Answered
Describe the structure of a nephron with the help of a labelled diagram
- A kidney is composed of an enormous number of uriniferous tubules.They are also known as nephrons or renal tubules or kidney tubules.
- Nephrons are the structural and functional units of the kidney.
- Each kidney is formed of about 1 million nephrons.
- Nephrons are held together by a connective tissue.
Structure of nephron:
- Each nephron is made of a glomerulus and a renal tubule.
- It is a tuft of anastomosing blood capillaries formed by the fine branches of the
- These capillaries of the glomerulus again unite to form the efferent arteriole.
- The afferent arteriole is wider than the efferent arteriole.
- The afferent arteriole brings blood into the glomerulus, while the efferent arteriole collects blood from the glomerulus.
The renal tubule comprises the following regions:
- The Bowman’s capsule lies in the cortex.
- It is a thin double-walled, cup-like depression.
It is the blind end of the nephron.
- The glomerulus is located in the concave depression of the Bowman’s capsule.
- The Bowman’s capsule and the glomerulus together are called Malpighian Capsule or Renal Capsule.
- The outer layer of the Bowman’s capsule is made of flattened epithelial cells.
- The inner layer is in close contact with the glomerulus and bears special cells called podocytes.
- Podocytes have many feet-like processes called pedicels and minute slit-like pores called slit pores.
Proximal Convoluted Tubule (PCT)
- PCT lies in the cortex.
- It is also known as the first convoluted tubule.
- The Bowman’s capsule continues into the PCT.
- It is lined with a layer of columnar epithelial cells.
- The columnar cells are with numerous microvilli to increase the surface area of absorption.
Loop of Henle
- It lies in the medulla.
- It is U-shaped.
- It is not convoluted.
- It has a descending limb and an ascending limb.
- Each limb has a thick region towards the cortex and a thin region towards the medulla.
- Thick regions are lined with columnar epithelial cells.
- Thin regions are lined with flat epithelial cells.
Distal Convoluted Tubule (DCT)
- It lies in the cortex.
- Its short terminal part is called a collecting tubule.
- The collecting tubule opens into the collecting duct.
- DCT in lined with ciliated columnar epithelial cells.
- The collecting duct receives the contents of many renal tubules.
- The collecting duct is a larger duct which receives collecting tubules of several nephrons.
- Collecting ducts pass into the renal medulla and join with each other to form the ducts of Bellini.
- The ducts of Bellini run through the renal pyramids and open into calyces.
- All calyces open into the pelvis.
- From the pelvis, urine is carried to the urinary bladder through the ureters.
Human Respiratory SystemLearn the mechanism of breathing and various organs of respiratory system....
Transport in Plants - Plant 1Explain the need for transportation system. Function of the vascular tissu...
BloodThis video explains the components of blood, blood vessels and the concept ...
Types of Reproduction - Part 1Meaning, significance and types of reproduction, Asexual reproduction and ...
Sexual Reproduction in Plants - Part 1Understand the process of pollination and fertilization during sexual repr...