| Non-specific body defence mechanism |
Specific body defence mechanism |
|
First Line of Defence
Skin - Prevents pathogens from entering the body
Second Line of Defence
White blood cell - Fight pathogens through phagocytosis
|
Third Line of Defence
Body immune system - Fights pathogens by producing antibodies
|
Passive Immunity and Active Immunity
| Passive Immunity |
| Natural |
Artificial |
- Obtained when a baby receives antibody from breast milk or from mother's blood that flows across the placenta
- The immunity is temporary and short-lived
|
- Obtained when an antiserum is injected into the patient's body
- The antiserum fights against pathogens
- The immunity is fast and temporary
|
| Active Immunity |
| Natural |
Artificial |
- Occurs when a person recovers from an infection
- The immunity lasts long after the infection
|
- Occurs when a vaccine that contains a dead or weakened pathogen is injected into the body and the immune system responds by producing antibodies
- The immunity lasts long after the infection
|
Immune System
| Causes that weaken the immune system |
Practices that strengthen the immune system |
- Exposure to polluted air
- Stress
- Exposure to pesticides
|
- Getting enough sleep or rest
- Exercising and inhaling fresh air
- Doing periodic health examination
|
