Question

Explain the structure and function of human blood.

Answer 1

Blood is a fluid connective tissue that flows in blood vessels. It is composed of two components-plasma and blood cells.

Plasma is a yellowish colour fluid, made up of water (~90%) and some dissolved nutrients, proteins, hormones, and waste products. 

Blood consists of three types of blood cells. These are

1. Red Blood Cells: They contain a red pigment called hemoglobin, which transports oxygen to all body cells.
2. White Blood Cells: They fight against germs that enter the body. Thus, they protect the body from diseases.
3. Platelets: When we get injured, bleeding stops after some time. This happens because of the activity of platelets, which help in the clotting of blood.

Functions of blood:

• It transports nutrients and oxygen to the different parts of the body.
• It also carries waste materials (from the different parts of the body) to be removed by the excretory organs.
• Chemical messengers like hormones are transported by the blood.
• Protects the body from disease-carrying germs.
• Helps to maintain a constant body temperature.