Blood Circulation – Blood, RBC, WBC, Blood Platelets, Blood groups
Blood is the main fluid of the circulatory system of the body which transports nutrients, oxygen, waste, hormones and blood cells to and from the cells in the body. Through this circulation, it maintains the homeostasis or stability of the internal environment of the body.
An average person has about 5-6 liters of blood in the body which accounts for 7% of the body weight.
Components of Blood
Blood has four main components- Plasma, Red Blood Cells, White Blood Cells and Platelets.
It accounts for 55% of blood volume while the cells account for remaining 45%. Plasma is the liquid component of blood and is mainly comprised of water (90%). Rest of it is nutrients, waste, hormones, ions, proteins, and The chief protein in plasma is Albumin which along with ions and other molecules maintains the osmotic balance of the body.
2.) Red Blood Cells (RBC)
Also known as erythrocytes, their chief role is to transport oxygen and carbon dioxide to and from the body cells. They are very tiny, bi-concave cells and do not contain any mitochondria or nucleus. They contain the protein called Hemoglobin which has an affinity for oxygen. They carry an enzyme which converts CO2 into bicarbonate which dissolves in the plasma and is released from the lungs. Their average lifespan is 120 days, and a hormone called Erythropoietin controls their production.
3.) White Blood Cells (WBC)
Also called Leucocytes, their function is to protect the body from invaders like bacteria and viruses through immune responses. They comprise only 1% of blood and are big, irregular in shape with mitochondria and a nucleus. There are five types of WBC’s- Neutrophil, Eosinophil, Basophil, Monocyte, and
Also known as Thrombocytes, their chief function is blood clotting. They convert Fibrinogen which is a water-soluble protein in the plasma into Fibrin which is not water soluble. Fibrin creates the threads which plug the wound.
Blood Groups in Human Body
The presence of specific antibodies determines blood Groups and inherited antigens in RBC’s. Though in most cases a blood group remains for life due to certain auto-immune diseases or bone marrow transplant, it can change.
The presence of specific antibodies determines blood Groups and inherited antigens in RBC’s.
Common Blood Groups
There are eight common blood groups by the presence of Antigen A, B and Rh factor- A+, A-, B+, B-, AB+, AB- and O+, O-.