NCERT Solutions for class 11 Biology Chapter 18: Body Fluids and Circulation

The fluid which is formed in the body of any complex lifeform carrying nutrients throughout the body and helping in excretion is known as body fluids. The two most important body fluids are blood and lymph. The different types of body fluids are:

• Blood

The main components of blood include:

1. Plasma: It is the liquid component of blood and is a thick fluid containing 55% blood, 90% water, and 8% proteins. Albumin is the major protein in plasma. 

2. Red Blood Cells: 40% of the blood contains red blood cells. RBCs contain protein hemoglobin that gives a red color to the blood.

3. White Blood Cells: The white blood cells are very few in number. They mainly protect the body against infections. 

4. Platelets: These are fewer in number than the red blood cells and help in the clotting of blood at the site of a wound.

• Lymph

Lymph is a colorless fluid present in the interstitial tissues, which circulates throughout the lymphatic system. It can be referred to as blood without the RBCs. The exchange of nutrients, hormones, and gases occurs through this fluid. It comprises lymphocytes that play a major function in the immune responses of the body.

Chapter Related Links:

CBSE Class 11 Biology Study Guides: