Human Physiology info

Human Physiology – Red Blood Corpuscles (RBC) or Erythrocytes, White Blood Corpuscles (WBC) or Leucocytes, Blood Platelets or Thrombocytes

Blood Corpuscles: There are three types. They are Red Blood Corpuscles (RBC), White Blood Corpuscles (WBC) and Blood Platelets.

Red Blood Corpuscles (RBC) or Erythrocytes:

They are circular, biconcave cells without nucleus in man. They are arranged like a pile of coins such arrangement of RBC is called ‘Rouleaux’. RBC contains a spongy elastic substance called ‘Stroma’ inside the meshes ofstroma is present the iron pigment called Haemoglobin which gives red colour to the blood. Human blood consists of a protein part called ‘Globin’ and a non-protein pigment called Haem. Haemoglobin has the property of combining with oxygen to form Oxyhaemoglobin. The RBC’c are produced in the bone marrow and are released into the blood stream. After the life span of 90-120 days they are destroyed in the spleen and liver.

White Blood Corpuscles (WBC) or Leucocytes:

The leucocytes are nucleated. They are capable of amoeboid movement and hence are referred as amoebocytes. They are also called‘Phagocytes’ for they attack the invading micro organisms and devour them. They are classified into Agranulocytes and Granulocytes.

Agranulocytes: These cells are with simple nucleus and the cytoplasm is without granules. Example: Lymphocytes and Monocytes.

Granulocytes: In these cells, the nucleus is lobed and the cytoplasm is filled with granules. Example: Neutrophil, Eosinophil and Basophil.

The leucocytes (WBC’s) are produced in the lymph nodes, reticuloepithelial cells in the liver, spleen and in red bone marrow.They live for about 2-3 weeks.

Blood Platelets or Thrombocytes:

These are small bodies either disc-shaped or irregular in form. They are without nucleus and cytoplasm is granular. They play a very important role in the coagulation of blood.