Pathogens And Immume System Flashcards
What is an antigen?
A protein on a cell which allows it to be recognised
What is an pathogen?
A microorganism which causes disease
What is an antibody?
• Released by white blood cells
• Recognises foreign cells
How do non-specific defences stop pathogens entering the body? Discuss skin, nose, trachea and bronchi and stomach.
Skin: acts as a barrier
Nose: hairs to trap pathogens and dust
Trachea and bronchi: mucus traps and cilia (hairs) sweep out
Stomach: hydrochloric acid kills pathogens
What cells make up the immune system?
White blood cells
How do white blood cells help the body fight pathogens?
• Release antibodies
• Release antitoxins
• Some are phagocytes (a
type of white blood cell)
How do antibodies help the body fight pathogens?
• Recognise antigens of pathogens
• Cause them to clump together and mark them for destruction
How do antitoxins help the body fight pathogens?
Neutralise toxins released by bacteria
How do phagocytes help the body fight pathogens?
Engulf and digest pathogens
What is in vaccines?
Dead or inactive form of pathogens
What does injecting small quantities of dead or inactive pathogens stimulate?
White blood cells to release antibodies
What is a memory cell?
• A cell which remembers the antibodies you have made before
• If you are infected by the same pathogen, you can fight it off before you get ill
What are drugs?
A substance which effects how your cells, tissue, organs or organ systems work
Give an example of drugs that treat symptoms of disease.
Painkillers – relieve pain
What type of drug kills bacteria?
Antibiotics
Why do antibiotics not work on viruses?
• Virus live inside cells
• So antibiotics can’t reach
them
What is the biggest concern with antibiotics?
• Resistant bacteria (like MRSA) which are not killed by antibiotics
• This is an example of evolution
What drug originates from foxgloves?
Digitalis
What drug originates from willow?
Aspirin
What was the first antibiotic, what organism did it come from and who discovered it?
• Penicillin
• From mould
• By Alexander Flemming
Why do we perform drug trials before doctors are allowed to prescribe them?
To check for safety, efficacy and dosage
What is the difference between clinical and pre-clinical testing?
Clinical is on patients Preclinical cells and animals
Define the words safety, efficacy and dose.
• Safety: is it toxic?
• Efficacy: does it work?
• Dosage: how much and
how often?
What are the 3 stages of clinical testing?
- Healthy volunteers low dose (safety)
- Healthy volunteers different doses (dosage)
- Patients (efficacy)
