Understanding Immunity Types
Immunity is the body's ability to resist infections and diseases. It can be classified into two main types: natural immunity and acquired immunity.
-
Natural Immunity: This is the type of immunity that is present at birth. It includes physical barriers like skin and mucous membranes, as well as innate immune responses that provide immediate defense against pathogens. For example, a newborn receives antibodies from the mother through breast milk, offering temporary protection.
-
Acquired Immunity: This immunity develops over time and is gained through exposure to specific pathogens. It can be further divided into:
- Active Immunity: This occurs when the body produces its own antibodies after exposure to a pathogen, either through infection or vaccination.
- Passive Immunity: This involves the transfer of antibodies from another individual, providing immediate but temporary protection.
In summary, natural immunity is inherent and immediate, while acquired immunity develops over time and can be long-lasting. Understanding these distinctions is crucial for comprehending how the immune system protects the body.
Key points to remember
- Immunity is the body's resistance to infections and diseases.
- Natural immunity is innate and present at birth.
- Acquired immunity develops after exposure to pathogens.
- Active immunity involves the body's own antibody production.
- Passive immunity is the transfer of antibodies from another source.
Worked example
Define immunity and distinguish between natural and acquired immunity.
- Immunity is the body's ability to resist disease.
- Natural immunity is present at birth; acquired immunity develops after exposure.
- Active immunity is when the body makes its own antibodies; passive immunity is when antibodies are received from another source.