12.7 Preventing and Treating Diseases Flashcards
Can non-communicable diseases be passed from one organism to another?
No
Give examples of non-communicable diseases?
Heart disease, cancer
How are communicable diseases spread? Can they pass from one organism to another?
Spread by pathogens.
CAN pass from one organism to another.
Explain what ‘Natural Active Immunity’.
• Immune system produces T and B memory cells
So, if the same pathogen enters the body the second time. the immune system recognises the antigens and immediately destroys the pathogen before symptoms show
Why is a baby’s immune system weak?
For the first few months, the baby’s immune system can’t produce antibodies
How do babies have some immunity to diseases when they’re born?
Some antibodies cross the placenta from the mother to her fetus while the baby is in the uterus
What’s the first milk produced by a mammalian mother called? What’s special about it?
Colustrum.
Contains high amounts of antibodies.
After a few days, why is a breast-fed baby equally capable of defending against a disease as the mother?
(check wording)
The infant’s gut allows the antibodies from breast milk to pass into the blood stream without being digested.
Within a few days, the baby will have the same amount of antibody protection against diseases as the mother.
This is Natural Passive Immunity.
What is Natural Passive Immunity?
Occurs during pregnancy, when antibodies from the mother are passed on to the baby during breast-feeding, or passed on from maternal blood to fetal blood through the placenta
How long does Natural Passive Immunity last?
Until the baby’s immune system makes its own antibodies
Why is artificial immunity important?
Some diseases kill before the immune system kills them - artificial immunity allows us to be immune to dangerous diseases without coming into contact with its pathogens
What is Artificial Passive Immunity?
For certain diseases, antibodies are formed in one individual, extracted and injected into the bloodstream of another.
Doesn’t last long but can be life-saving
Give an explained example of a disease which is treated using artificial passive immunity.
Disease:
• Tetanus is caused by a toxin released from a bacterium found in soil and animal faeces
Symptoms:
• Tetanus causes muscles to spasm, so patient can’t breathe or swallow
Treatment:
• People with tetanus, e.g. from contaminated cut, are injected with tetanus antibodies extracted from horse blood.
• This prevents the development of the disease but doesn’t provide long term immunity
2nd example:
Rabies can be treated with a series of injections that give artificial passive immunity
What happens during artificial active immunity?
Body’s immune system is stimulated to make its own antibodies to a safe form of an antigen - a vaccine.
This is injected into the bloodstream - vaccination.
The antigen isn’t a normal live pathogen as this could cause disease and have fatal results.
How does vaccination (artificial active immunity) work?
- Pathogen is made safe so the antigens are intact but there’s no risk of infection
- Small amount of the antigen, the vaccine, are injected into the blood
- Primary immune response is triggered by the foreign antigens. The body begins to produce antibodies and memory cells (just like if you had a live pathogen
- If you come into contact with the live pathogen, the secondary immune response is triggered. The immune system destroys the pathogen before symptoms of the disease are shown
