Composition of Blood

Blood plays an essential role within the body. It not only transports nutrients and oxygen to cells, but also carries away waste products.

Blood is made up of four key components:

Red Blood Cells (RBCs): Also known as erythrocytes, RBCs carry oxygen around the body. These cells contain haemoglobin, an iron-rich protein that binds with oxygen in the lungs. They’re biconcave in shape, which increases the surface area for oxygen transportation.
White Blood Cells (WBCs): Known as leukocytes, WBCs help to defend the body against infectious diseases and foreign invaders. They are larger than RBCs but less numerous.
Platelets: These cell fragments help in blood clotting and wound healing. When there’s a cut or abrasion, platelets clump together to seal the wound and prevent excessive bleeding.
Plasma: This yellowish liquid carries blood cells, platelets, nutrients, hormones, and waste products. It also carries dissolved gases like oxygen, carbon dioxide and nitrogen.

There are four major blood types which are classified according to the presence of antigens and antibodies on the surface of RBCs:

Blood type A: Indicates presence of A antigens and anti-B antibodies.
Blood type B: Has B antigens and anti-A antibodies.
Blood type AB: Both A and B antigens are present with no antibodies. It is known as the universal recipient.
Blood type O: Lack of A and B antigens but both antibodies are present. It is known as the universal donor.

Blood performs various crucial tasks within the body:

Transportation: It carries oxygen from the lungs to the rest of the body and returns carbon dioxide back to the lungs for removal.
Nutrient supply: Nutrients absorbed from the digestive tract are transported to cells around the body.
Waste removal: Waste products from cellular metabolism are transported to the kidneys, liver, and lungs for elimination.
Immunity: WBCs and antibodies help defend the body against infections and diseases.
Thermal regulation: Blood helps in maintaining body temperature by distributing heat generated from metabolic activities.

To fully understand the human body’s functioning, have a comprehensive knowledge of the composition and functions of blood.