Question
Describe the composition and functions of blood

Answer

Blood is a fluid connective tissue. There are three types of blood corpuscles:
  1. RBC's or Erythrocytes: These are bi-concave, denucleated, disc like. They contain red coloured respiratory pigment called haemoglobin that helps in the transportation of oxygen.
  2. WBC's or leucocytes: These are irregular, amoeboid, phagocytic cells with one to many lobed nucleus. These cells protect the body against the diseases by producing antibodies.
  3. Blood platelets or thrombocytes: These are spindle shaped cells which help in the clotting of blood.
Functions of blood:
  1. It transports nutrients, hormones and vitamins to the tissues and transports excretory products from the tissues to the liver and kidney.
  2. The $RBCs$ carry oxygen to the tissues for the oxidation of food stuff.
  3. $WBCs$ fight disease by engulfing and destroying foreign bodies.

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