B3- Infection and response (Fighting disease (The body fights of infection…
B3- Infection and response
Pathogens (microorganisms) cause disease both in plants and animals. There is four types of pathogens, they are bacteria which reproduce quickly and produce toxins which damage tissue and the cells. Viruses which are not cells, very small and can replicate themselves in your cells making them hard to destroy. Protists are single celled eukaryotes, the parasite is spread by vectors and Fungi which is a single cell.
Pathogens can be spread through the water, air and direct contact.
Viral diseases include measles which are transmitted through coughing and sneezing (water droplets). HIV which is a sexually transmitted disease but can also be transferred through other bodily liquids such as blood. Tobacco mosaic virus which occurs in plants, by discolouring the leaves making them unable to photosynthesis.
Rose black spot is a fungal disease which in transferred in the water or wind and stops the plants photosynthesising.
Malaria is a protist disease which is transferred through the vector- mosquitos.
Bacterial diseases include salmonella which is transferred through food and gonorrhoea (STD) which is a sexually transmitted disease.
Ways to reduce these diseases is through hygiene, Destroying the vectors, isolating the infected or vaccinations.
The body fights of infection through it having its own barriers such as skin, hair, mucus and the stomach having hydrochloric acid
The immune system fights disease through white blood cells ,they have three ways of attacking the pathogens which is consuming them, Sending out antibodies to kill there antigens or release antitoxins to contradict there toxins.
Vaccination - release dead or inactive pathogens into the bloodstream which carry antigens, the white blood cells produce antibodies to kill the specific pathogen (even though harmless), white blood cell can them remember this antibody and when disease occurs again can produce quickly. This controls the communicable disease reducing outbreaks however it doesn't always work
Drugs- Painkillers reduces pain therefore reduces symptoms but antibodies kill the bacteria however cannot destroy viruses. Drugs originally came from plants which have variety of chemicals to defend themselves against pests and pathogens.
Bacteria can become resistant to the antibiotics by mutation (change) to avoid this doctors avoid over-prescribing antibiotics.
First they do preclinical tests which is on human cells and tissue however is drug is for something to do with a whole system such as blood pressure would have to start with live animals.
The next stage is on live animals which lets the scientists see the level of toxicity of the drug.
They then start the human testing, they get human volunteers, this is the clinical trials they first test it on the healthy to see weather there are any drastic side effects, gradually increasing dosage.
Then they test on the ill to decide the optimum dosage for the medical condition and well-being of the person.
The last test is between the new drug and a placebo which is a fake drug, they do this to see the real effect of the drug. The test is either taken blind so the patient doesn't know what there taking or double-blind where neither the patient nor the doctor know this means no one is bias and can just focus on the data.