Answer the follwing question in your own words.
Explain the structure and function of human blood.
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
i. Red Blood Cells: They contain a red pigment called haemoglobin, which transports oxygen to all body cells.
ii. White Blood Cells: They fight against germs that enter the body. Thus, they protect the body from diseases.
iii. 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.