List and describe the function of each of the four components of blood.

The four components of blood are RBC, WBC, Platelets, and blood plasma.

Explanation:

The major 4 components of blood are RBC, WBC, platelets, and plasma. Plasma is the fluid part of the blood and the remaining 3 are the cellular part.  

Plasma is the yellow color liquid. In the plasma, all cellular components float. Plasma constitutes approximately 55% of the total volume of the blood.

The various functions of plasma are - It carries different nutrients from the alimentary canal to the liver and other parts of the body. Simultaneously it carries the CO2 from the different tissues and reaches them to lungs for expiration. It distributes the hormones and vitamins from endocrine glands to different target organs. Plasma also plays a role in the water balance in the body. It supplies water to tissues and receives excess water from them. Thus regulate the water balance in the body.

RBC is the enucleated cellular organelle of blood. The absence of nucleus enables it to carry more oxygen. It is red due to the presence of Hb and carries O2 and CO2 in the form of oxyhemoglobin and carbaminohemoglobin. It also helps in releasing energy through the metabolic process.

WBC is concerned with the immunity of the body. It acts as a defense mechanism of the body. The components of leukocytes such as granulocytes and agranulocytes are phagocytic. They engulf bacteria and viruses. Eosinophils fight against the allergic reaction in the body.

The blood platelets have blood clotting factors. There are 12 blood clotting factors which help in the clotting of blood.