Describe the composition and functions of blood.

Composition of blood: Blood is a fluid connective tissue which circulates in our body. The main components of blood are plasma (55%) and blood corpuscles (45%).

Plasma is straw-coloured fluid which contains 85-90% water and 5-10% other substances like proteins, salts and hormones. There are three types of blood corpuscles:

● RBC (Red blood cells)

● WBC (White blood cells), and

● Platelets

Functions of blood:

(i) Transport oxygen from the lungs to different parts of the body.

(ii) Transport CO₂ from the body tissues to the lungs.

(iii) Transport digested food i.e., glucose, amino acids, etc. from alimentary canal to various parts of the body for energy, growth and repair.

(iv) Transport excretory waste product called urea from the liver to the kidneys for removal as urine.

(v) Plasma regulates water balance in the body.

(vi) Regulates the body temperature.