Difference Between Innate and Adaptive Immunity
Innate Immunity
Innate Immunity is also known as General or Non-specific Immunity. It is a long-term non-specific immunity that is present in the organism by birth.
- The Activation of the innate immune system results from an attack by any pathogen. Since it works in a generalized way regardless of the type of pathogen, that is also the main reason why it is called Non-specific immunity.
- It provides a natural resistance component, such as salivary enzymes, natural killer cells, intact skin, and neutrophils, etc.
- It provides a long-term immunization towards any pathogen by producing antibodies.
Innate Immunity is also called a first-line defense system, which includes various barriers that restrict the pathogen’s entry into the body. Following are the natural barriers that prevent the entry of pathogens.
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Barrier |
Explanation |
|---|---|---|
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1. |
Physical barriers | The skin on our body is the main barrier that prevents the entry of micro-organisms. Mucus coating of the epithelium lining the respiratory, gastrointestinal,, and urogenital tracts also helps to trap the microbes and stop them from entering our body. |
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2. |
Physiological barriers | Acids in the stomach, mouth, saliva and eye tears prevent microbial growth. |
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3. |
Cellular barriers | Certain types of leukocytes (WBC) of our body, like polymorphonuclear leukocytes (PMNL-neutrophils) and monocytes and natural killers (kind of lymphocytes) in the blood as well as macrophages in tissue, can phagocytose and destroy microbes. |
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4. |
Cytokine barriers | Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infections. |
Cells Involved in Innate Immunity
Following are the cells involved in Innate Immunity
S.No. |
Cells |
Role of Cells |
|---|---|---|
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1. |
Dendritic Cells | They are the first-line worriers found in the tissues and perform the function of fighting with the microbes and sending signals to the other immune cells. |
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2. |
Natural Killer Cells | They are involved in killing all those cells which got infected with the microbes. |
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3. |
Macrophages | They have the ability to circulate in the blood and also to move into the tissue. They particularly produce cytokines which alert all the other immune cells. |
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4. |
Mast Cells: | They are involved in the healing process and defense against infections. |
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5. |
Neutrophils | They contain granules that help in killing any bacteria or pathogen. |
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6. |
Eosinophils | They produce a toxic protein that is involved in skinning bacteria. |
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7. |
Basophils | They produce a protein called histamine against multicellular parasites. |
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8. |
Phagocytes | They circulate throughout the body and kill all foreign substances by engulfing them. |
Also Read: Blood
Innate And Acquired Immunity
The immune system fights against germs and foreign substances on the skin, in the body’s tissues, and in bodily fluids such as blood. The overall ability of the host to fight the disease-causing organisms conferred by the immune system is called Immunity. The immune system can be broadly categorized into two types, the innate (Non-specific) immune system and the acquired (specialized) immune system. These two systems work closely together and take on different tasks.