Question

What different types of cells will you see when you observe a drop of blood under the microscope? What are their functions?

Answer 1

Blood cells:

1. Human blood contains many components that differ in number and quantity.
2. It contains the plasma, blood cells, nutrients, hormones, metabolites, wastes and respiratory gases.
3. Plasma is the living component which contains 95% water and the blood cells are seen flowing in the plasma.

When a drop of blood is placed under the microscope, three different types of cells can be observed. They are:

1. Red blood cells
2. White blood cells
3. Blood platelets

Types of blood cells:

Red blood cells:

1. Erythrocytes are the red blood cells that are present in the blood.
2. Erythro' means red and 'cyte' means cells.
3. They are biconcave in shape and are about 5-6 million in number per cubic millimetre of blood.

Functions:

1. They contain the red pigment protein called hemoglobin that helps in transporting the respiratory gases like oxygen and carbon dioxide.
2. The presence of RBCs gives the blood red color.

White blood cells:

1. White blood cells are also known as leukocytes which are larger and irregular in shape.
2. It does not contain any pigment protein and hence it is colorless.
3. They act by engulfing the infectious agents.

Functions:

1. It helps in protecting against infection.
2. They circulate in the blood and respond to injury.
3. If an infection occurs, they localize and accumulate at the exact site and act to fight against the foreign particles by producing defense proteins to destroy the infection causing bacteria or virus.

Blood Platelets:

1. Blood platelets or thrombocytes are colorless cells which are disc -shaped as well.
2. They are much smaller in size than the RBCs and WBCs and count about 400000 in number per cubic millimeter of blood.
3. They circulate in the blood for 3-7 days.

Functions:

1. The main function of thrombocytes is to aid in the clotting of blood.
2. When there is a wound or cut, in order to stop the blood from flowing, a cascade of events follow up wherein the blood clotting factors are triggered to form a blood clot at the site of wound.