The human body's defense system

Posted on Apr 22, 2022      45

Immunity (from Latin immunitas meaning “liberation” or “deliverance”) is the body’s defensive reaction, its ability to resist infection.

Medieval physician Avicenna, in his famous book “Canon of Medicine” as early as 1020, described 811 simple remedies, 612 of which were prepared from plants.

We offer you an overview of protecting the human body - the primary goal of any medicine.

The body’s defense system

A complete system of organs, tissues and cells performs the protective functions of the human body. Interacting with each other, they destroy pathogenic germs and harmful substances entering the body.

The organs of the immune system are not like other organs (liver or heart). They are special areas of lymphoid tissue: lymph nodes, tonsils, thymus (thymus), bone marrow, spleen, and small intestinal lymphoid masses (Peyer’s plaques).

Our tonsils are in the throat. They are the first to take the hit of disease-causing germs that try to enter our body with air and food.


Lymph nodes produce many white blood cells, lymphocytes, which destroy pathogens, viruses and the harmful substances they release.

Lymphocytes are the guards of our body and its major defense. They also get rid of sick cells, such as tumor cells. Lymph nodes are connected by lymphatic vessels, through which lymph, a fluid similar in composition to blood plasma, flows.

The best way to fight disease is just not to get sick. And in order not to get sick, follow the rules of hygiene, eat right, get enough sleep at night, strengthen your health and move a lot!


An interesting fact is that lymphocytes are capable of “learning”. After defeating germs, they “remember” which substances act on them as the strongest and produce antibodies.

After defeating germs, they “learn” which substances act on them the strongest, and produce antibodies.

Antibodies are special proteins that prevent harmful microorganisms from multiplying and neutralize them. Next time lymphocytes do their job much faster - sometimes a person does not even have time to feel bad.

The thymus gland (thymus) handles the reproduction of lymphatic cells. But with age the thymus decreases in size and is no longer so active.

But new blood cells: leukocytes, erythrocytes, thrombocytes are produced by bone marrow. The spleen purifies the blood, destroys old and incomplete blood cells.

What are vaccinations for?

To train lymphocytes to defend themselves against serious diseases, vaccinations are done. Small amounts of vaccine, a preparation of killed or weakened germs that cause a particular disease, are injected into the body.

Lymphocytes immediately gather around them and pick up a suitable set of antibodies. And if a person gets sick, they neutralize the pests before they multiply.

Movement is life. The body needs it just as much as water, fresh air, and light. So do exercise, play games, run with a ball, ride a bike, roller skates, skates.

By the way, many diseases appear... from despondency! But there is always so much interesting around! Exercise is an excellent way to strengthen the body. Whether you like wrestling, swimming, or gymnastics, exercise will strengthen not only your body but also your spirit!

Now you know what the body’s defense system is and how it works.

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