Immunology

 Immunology: 

Immunology means the study of biomedical science that explain with the response of an organism to antigenic challenge to keep defense of body is called immunity.

Immunology = Immune + logos

                            immunity + study.   

  Shortly we can say immunology means the study of immunity system of an organism against harmful foreign particles or pathogens.

Immunity:

 It is the ability of multicellular organisms to resist harmful foreign particles or pathogens.

Immunity response:  

It is a reaction which occurs inside a organism for the purpose of defending against harmful pathogen of foreign particles.

Types of immunity:

There are two types of immunity, name as:

1. Innate ( Inborn/ Natural) immunity.

2. Adaptive ( Acquired) immunity.

Innate  Immunity:

Innate immunity is an antigen non- specific  defence mechanism of a host body which is developed since birth and it uses immediately or within several hours after exposure to almost any harmful pathogens.

The important features of Innate immunity

1. Innate immunity present since birth inside host body.

2. It is antigen non-specific.

3. It gives first line of defense against harmful pathogens.

4. It has no memory.

5. Innate Immunity working with  immediately or taking some hours ( Rapid Response) after exposure to a harmful microbe.

Components of innate immunity:

1. Physical barriers.

2. Chemical mediators.

3. Phagocytic barriers.

4. Inflammatory barriers.

5. Complement proteins.

Physical Barriers:

Physical barriers participate crucial role for the first line of defence against harmful microorganisms to host body. It Consist of skin and mucous membrane.

Skin:

 Harmful microorganisms can not penetrate intact skin but can enter into body while body skin is damage for some injury.The acidic pH of sweat and sebaceous secretions inhibit the growth of most harmful microorganisms. Hydrolytic enzymes like lysozyme also eliminate the harmful pathogens.

Mucous Membrane: 

Respiratory and gastrointestinal tracts are lined by mucous membrane. Mucous membrane generally entrap the foreign microorganisms.

The respiratory tract is covered by cilia , which are look like hair projections of the epethelial cell membranes. 

Chemical mediators: 

Variety types of chemicals mediate protection against microbes during the period before adaptive immunity develops. They are proteins, cytokines, pattern recognition molecules involved in innate immune response.

Phagocytic Barriers:

Neutrophils, Macrophages and NK( Natural killer cells) ingest and destroy microbes by endocytosis and phagocytosis.

Cells of the immune system:

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