Human Biology - Fighting Disease Flashcards
What are the two main types of pathogen?
Bacteria and Viruses.
What are pathogens?
Pathogens are microorganisms that enter the body and cause infectious diseases.
What do bacteria do that affects you?
A) they damage your cells
B) they produce toxins
What do viruses do that affects you?
They replicate themselves by entering your cells and reproducing. The cell will usually then burst, releasing all the new viruses.
The cell damage is what makes you feel ill.
What makes up the defence system?
Firstly, our skin, and hairs and mucus in the respiratory tract.
Platelets prevent microorganisms getting into the blood through a cut. If something does reach our blood stream, the immune system kicks in, and the main factor of which is the white blood cells.
What do white blood cells do to pathogens?
They can
a) engulf and destroy them.
b) produce antitoxins to counteract toxins.
c) produce specific antibodies.
What are antibodies?
Antibodies are specifically designed for the unique antigens of the pathogen and are produced rapidly. If the person becomes infected again, they will be immune.
What does vaccination do?
Vaccination protects the body from future infections
What is vaccination?
Vaccination involves injecting small amounts of dead or inactive pathogen. They carry antigens, allowing the white blood cells to produce antibodies which can fight future infections much faster.
What are the pros of vaccination?
Epidemics can be prevented if a large percentage of the population is vaccinated.
Vaccines have helped control lots of infectious diseases which were once common in the UK. (Eg polio, measles, whooping cough, rubella…)
What are the cons of vaccination?
Vaccines don’t always work.
Sometimes you can have a bad reaction to a vaccine.
How do painkillers help to fight disease?
Painkillers (eg aspirin) are drugs that relieve pain. However, they don’t actually tackle the cause of the disease, they just help to reduce the symptoms.
How do antibiotics fight disease?
Antibiotics (eg penicillin) kill or prevent the growth of the bacteria without killing your own cells. Different antibiotics treat different types of bacteria.
Why would you not prescribe antibiotics to a patient with a virus, eg flu or cold?
Antibiotics don’t destroy viruses. Viruses reproduce using your own cells which makes it very difficult to develop drugs that destroy just the virus and not the cells of the patient.
Why might bacteria become resistant to antibiotics?
Bacteria can mutate, which can mean that the bacteria becomes resistant to an antibiotic.
