Humoural immune response  Learn how it works
Channel: Learn How it works
Date: 2022-04-09

The immune system is made up of special organs, cells and chemicals that fight infection (microbes). The main parts of the immune system are: white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. These are the parts of your immune system that actively fight infection.

The immune system and microbial infection
The immune system keeps a record of every microbe it has ever defeated, in types of white blood cells (B- and T-lymphocytes) known as memory cells. This means it can recognise and destroy the microbe quickly if it enters the body again, before it can multiply and make you feel sick.

Some infections, like the flu and the common cold, have to be fought many times because so many different viruses or strains of the same type of virus can cause these illnesses. Catching a cold or flu from one virus does not give you immunity against the others.

Parts of the immune system
The main parts of the immune system are:

white blood cells
antibodies
complement system
lymphatic system
spleen
bone marrow
thymus.
White blood cells
White blood cells are the key players in your immune system. They are made in your bone marrow and are part of the lymphatic system.

White blood cells move through blood and tissue throughout your body, looking for foreign invaders (microbes) such as bacteria, viruses, parasites and fungi. When they find them, they launch an immune attack.

White blood cells include lymphocytes (such as B-cells, T-cells and natural killer cells), and many other types of immune cells.

Antibodies
Antibodies help the body to fight microbes or the toxins (poisons) they produce. They do this by recognising substances called antigens on the surface of the microbe, or in the chemicals they produce, which mark the microbe or toxin as being foreign. The antibodies then mark these antigens for destruction. There are many cells, proteins and chemicals involved in this attack.

Complement system
The complement system is made up of proteins whose actions complement the work done by antibodies.