topic 3 - fighting disease

• immune system kicks in to destroy pathogens
• immune system is the white blood cells that fight infectious agents and foreign cells
• white blood cells engulf foreign cells and digest them (Phagocytosis)
• white blood cells will produce proteins called antibodies to help fight infection
• antibodies are produced rapidly and carried to find all the similar bacteria
• producing antitoxins is produced by invading bacteria
• vaccination involved injecting dead pathogens into the patient which causes the body to produce antibodies to attack them
• advantages of vaccines -

  can prevent epidemics from occurring

  helps control lots of communicable disease that were common once
• disadvantage of vaccination

  They don't always work

  you can have side effects to a vaccine
• painkillers -

  relieves pain doesn't kill pathogens or kills disease just reduces symptoms
• antibiotics -

  they kill pathogens and they don't destroy viruses
• bacteria -

  bacteria can become resistant to antibiotics and they can also mutate
• aspirin -

  made from willow trees and is a painkiller
• Alexander fleming noticed that dishes or bacteria had mould on it and the are around was free of bacteria.The mould on the petri dish was producing a substance to kill bacteria (penicillin)
• preclinical testing are drugs tested on human and tissues in the lab.You cannot use human tissues and cells to determine how the whole body will react
• preclinical trial with animals is the second step of the drug development trial and is done to test efficacy ,test the best dosage and toxicity
• Step 3 would be the clinical trials where its tested on human volunteers to see the side effects.It is given at low dosages and is increased gradually
• their are two types of clinical trials

  double blind trial - when the doctor and the patients don't know what patient has been given the drug or placebo

  blind trial - The doctor knows who is being given the placebo or drug