Blood Groups and Rh Factor

Blood Groups and Rh Factor

The antigens are genetic substance which composed of glycoprotein and glycolipid. These antigens are present on the surface of red blood cells. These Antigens are also known as agglutinogens. The antibodies are present in blood plasma, called agglutinin. 

Based on the presence or absence of various antigens and antibodies, blood is divided into different blood groups.

Blood divided into two major blood groups:

1. ABO group
2. Rh blood group

ABO group

Based on A and B antigen and antibody, ABO blood group are four blood types.

Type A: The Red blood cells display only A antigen and blood plasma contain anti-B antibody.  These people carries blood group A.

Type B: The red blood cells display only B antigen and blood plasma contain anti-A antibody.  These people carries blood group B.

Type AB: The Red blood cells display both A and B antigen but absence of antibody in blood plasma.  These people carries blood group AB.

Type O: In this type, red blood cells do not contain any antigen (either A nor B antigen) but blood plasma display both anti-A and anti-B antibodies. These people carries blood group O.

Rh blood group

Rh blood group was first found in rhesus monkey. That blood group contains a different type of antigen that is Rh antigen, called Rh factor. 

Red blood cells have Rh antigen which is Rh positive (Rh+) and people whose absent of Rh antigen are designated Rh negative (Rh-).  

Function of blood

Function of blood are given below

Transportation

• Blood transport various essential elements to cells, these elements are necessary for many metabolic reaction.
• Blood carry oxygen to cells and take back carbon dioxide to lungs.
• Blood carrier for many hormone and enzymes.
• Blood transport nutrition and essential elements to cells for growth and development. 

Regulation

• Blood help maintain homeostasis of all body fluids.
• Blood maintain pH through using buffers. Blood also regulate body temperature. 

Protection

• Blood make a gel like structure, called clot, which protect against blood excessive loss from the cardiovascular system after the injury.
• Various type of blood cells protect against disease in a variety of ways.
• White blood cells protect against disease by phagocytosis.