What do you mean by rbc …

Red Blood Cells

The Red blood cells are also called erythrocytes. RBCs store the haemoglobin, which is a respiratory pigment that binds to oxygen or carbon dioxide molecules. This helps in the transportation of the oxygen to different tissues and organs of the human body. It also takes away the carbon-dioxide from different organs and tissues to be replenished in the lungs.

Haemoglobin is mainly composed of iron, which combines with the oxygen, thus giving a reddish colour to the blood. It occupies 40-45% of the total volume of blood. The main function of the RBCs is the transportation of nutrients and the hormones throughout the human body.

White Blood cells

The white blood cells are also called Leukocytes. These cells act as a defence system against any infections in the human body. They produce a special kind of proteins called antibodies, which identify and fight against the foreign entities invading the human body. These cells are classified further as granulocytes and agranulocytes.

The white blood cells contain visible granule-like structures in the cell bodies, hence their names Granulocytes. On the other hand, agranulocytes do not possess these granule-like structures. The three kinds of granulocytes are neutrophils, basophils, and eosinophils. The two types of agranulocytes are lymphocytes and monocytes.

WBCs comprise 1% of the total blood volume. They are colourless because they are devoid of haemoglobin.