Explain the composition of blood.

Blood circulates in our body and it transport substance like digested food from the small intestine to the other parts of the body. It carries oxygen from lungs to the cells of the body. It also transport waste for removal from the body.

Major components of Blood are as follows:

  1. Plasma: Plasma is the liquid portion of your blood. Plasma is yellowish in color and is made up mostly of water, but it also contains proteins, sugars, hormones and salts. It transports water and nutrients to your body’s tissues.
  2. RBC: Red blood cells represent 40%-45% of your blood volume. They are generated from your bone marrow at a rate of four to five billion per hour. They have a lifecycle of about 120 days in the body.


  1. WBC:




(1)Neutrophils  Monocytes



 (b) agranulocytes

Lymphocytes –

(a)  B- Lymphy         (b)  T-lympho


Platelets:   Platelets also called thrombocytes, are cell fragments produced from megakaryocytes (special cells in the bone marrow).Blood normally contains 1,500,00-3,500,00 platelets mm-3.Platelets can release a variety of substances most of which are involved in the coagulation or clotting of blood.


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