Blood Components

Blood Components

Components of Blood

Red Blood Cells

• Red blood cells or erythrocytes are biconcave disc-shaped cells without a nucleus.
• They carry oxygen from the lungs to body cells and carbon dioxide from the cells to the lungs.
• Haemoglobin, the red pigment in red blood cells, binds with oxygen to form oxyhaemoglobin in the lungs. This pigment provides the red colour.

White Blood Cells

• Leukocytes, commonly known as white blood cells, play a major role in defending the body against diseases.
• They can change their shape to engulf microorganisms.
• The two primary types of leukocytes are phagocytes (cells that ingest harmful foreign particles) and lymphocytes (cells that produce antibodies against these particles).

Platelets

• Platelets are small fragments of cells that initiate blood clotting.
• When a blood vessel is damaged, platelets stick to the damaged area and release chemicals that activate enzymes in the blood to form a clot.
• The clot prevents further bleeding and seals the damage.

Plasma

• Blood plasma is a straw-coloured liquid that carries dissolved substances around the body.
• Plasma transports various components including hormones, nutrients, waste products, gases like oxygen and carbon dioxide, and heat.
• It also carries the cells and platelets which make up the solid part of the blood.

Antibodies

• Antibodies are proteins produced by a type of white blood cell, the lymphocytes, in response to the presence of foreign substances, known as antigens.
• Each antibody is specific to one particular antigen. Once it meets with the specific antigen, it neutralises or destroys it.
• Antibodies help the body to build immunity against diseases.

Antigens

• Antigens are substances, often proteins, that are recognised by the immune system as foreign and trigger an immune response.
• They can be found on the surface of cells, viruses, fungi, or bacteria.
• The body produces specific antibodies to try and neutralise or destroy each different antigen.