Immune System – Types, Components and Working

Overview of Immune System

The capacity of a body to recognize and then fight with foreign substances which are hazardous for the body like bacteria, viruses, etc. with higher speed and effectiveness is called immunity. There are numerous attacks of viruses or other microorganisms on your body on daily basis but this is the immune system that provides you defense and takes care of you.

The immune system consists of Lymphocytes B and T and Antibodies – immunoglobins synthesized by organisms in action to antigens. The working of immune system is called the humoral immune response. There are two types of immunity: Active and Passive. Active immunity is by vaccines, which stimulate the production of antibodies. Passive immunity is in the form of antisera, to make a person immune from disease.

What is the immune system, why you need it and what are its types?

Numerous viruses and microorganisms daily attack you but have you ever thought which system is behind you for defence from these tiny illness-causing microorganisms. This is your immune system.

When your immune system is in great condition, you probably do not even see it working away to secure you all the time. However, you will know when there is something erroneous as your body immune system is your body’s built-in defence system against illness and infection. If you feel great today, thank your body immune system.

The need for healthy body immune system

A healthy and effectively operating body immune system assists you to go about daily life as you enter into contact with germs and bugs from family pets, other people, and your environment. Without a healthy body immune system, you might get infections and infectious diseases more easily, and the effects could be serious– even deadly.

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Your body’s very first line of defence is its physical barriers. If viruses and germs manage to break through, there are specialised cells that will jump into action. Your bloodstream and crucial areas of your body contain leukocyte that can combat and ruin the infections and germs they find.

It is simple to take the immune system for granted since it does such an excellent task at keeping us devoid of infections. If you have actually got a healthy immune system, care for it and it will care for you.

Immunity and its types


The capacity to recognize the invasion of any product foreign to the body and to mobilize cells and cell items to assist get rid of the particular sort of foreign product with higher speed and effectiveness is called immunity.

In animals in addition to physical barriers (skin + mucous membranes) and phagocytes, there is a third system, to defend their bodies versus the foreign invaders; this is the body immune system.

Components of the Immune system

The elements of the body immune system include the lymphocytes (B and T) and the antibodies – which are unique type of proteins.

These antibodies are immunoglobulins which are synthesized by vertebrates, in action to antigens; and immobilise it, or sets in motion events that ultimately cause its damage.

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Antigen or immunogen is a foreign substance, frequently a protein which stimulates the development of antibodies. Antibodies specify i.e. trigger the damage of the antigen, which stimulated their production. Antibodies are made in B-lymphocytes, then secreted into the lymph and blood where they flow freely.

Working of Immune system

T-cells acknowledge antigen, then battle micro-organisms and/ or effect the rejection of foreign tissues (in case of tissue transplant). This is called cell-mediated reaction. B-cells acknowledge antigen and form plasma cell clone. These plasma cells synthesise and release antibodies into the blood plasma and tissue fluid. Here antibodies attach to the surfaces of germs and accelerate their phagocytosis, or combine with and neutralise toxins produced by bacteria, by producing antitoxins.

This is called humoral Immune response. When we get the vaccination, versus a specific disease (antigen), we end up being immune to that infection or disease. If we get a vaccination against polio, smallpox, measles, mumps and so on, once in our lifetime, we are protected or ended up being unsusceptible to that infection in our future life.


Types of Immunity
Active Immunity

The use of vaccines, which stimulate the production of antibodies in the body, and making a person immune against the disease or infection, is called active immunity. But this active immunity has been achieved by artificially introducing, antigens in the body, so it is called artificially caused active immunity.

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But, when an individual is exposed to infection (antigen) – ends up being ill, and for the most part endures then this immunity, established versus that illness is called naturally induced immunity or autoimmune reaction.

Passive Immunity

In contrast to active immunity, in which case antigens are presented to stimulate the production of antibodies, by artificial or natural technique; antibodies are injected in the form of antisera, to make a person immune against disease, this is called passive immunity. In the body, antigen-antibody complexes are formed which are used up by phagocytes and destroyed. The patient is spared the issues (or possibly death) triggered by the infection or venom.

Passive immunity response is instant, but not long-lasting. Because no time at all is taken for the production of sufficient level of antibodies, (as antibodies are being injected) and after the level of antibodies is decreased or they are used up – No more antibodies production exists.

The method of passive immunization is used to fight active infections of, tetanus, contagious hepatitis, rabies, snake bite venom etc. When it comes to snake bite venom passive immunity is produced by the antitoxins so the serum is called antivenom serum.