Question

Which is the correct sequence of arrangement of types of WBC in decreasing order in terms of number per $mm^3$ of human blood?
A) Eosinophils, basophils, neutrophils
B) Basophils, eosinophils, neutrophils
C) Neutrophils, eosinophils, basophils
D) Eosinophils, neutrophils, basophils

Answer 1

The blood has four main components -plasma, red blood cells, white blood cells and platelets. The WBC is also called leukocytes. They play an important role in the immune system. They are found throughout the body including the blood and the lymphatic system.

Complete Answer:

The leukocytes are divided into five main types – neutrophils, eosinophils, basophils, lymphocytes and monocytes.
The lymphocytes and monocytes are agranulocytes.
The basophils, neutrophils and eosinophils are granulocytes.
The granulocytes have large cytoplasmic granules.
The basophils are responsible for the allergic and antigen response. They release histamine which causes vasodilation.
The normal value of basophils is $25 - 200/m{m^3}$
The normal value of eosinophils is $50 - 400/m{m^3}$
The normal value of neutrophils is $3000 - 7000/m{m^3}$
The neutrophils help in fighting bacterial or fungal infection. They are most common responders to microbial infection.
The eosinophil helps in parasitic and allergic infections.
The normal value of monocytes is $100 - 600/m{m^3}$
The normal value of lymphocyte is $1000 - 4000/m{m^3}$

So the correct answer is neutrophils, eosinophils, basophils.

Note: The leucocytes help in pathogen recognition, phagocytosis, pathogen destruction, inflammation and antigen presentation. There are two main types of lymphocytes- B lymphocytes and T lymphocytes. The antibodies are produced by B lymphocytes. The lymphocytes are main types of cells which are found in lymph. The white blood cells originate in the bone marrow.