Topic 3 - Infection and response Flashcards
What are pathogens?
Pathogens are microorganisms which cause communicable diseases
What are the 4 types of pathogens?
Bacteria
Fungi
Virus
Protist
How do bacteria make you ill?
They produce toxins that damage your cells and tissues
Are viruses cells?
No
How do viruses make you feel ill?
They live inside your cells and replicate using that cell’s machinery, the cell will then burst and release new viruses. The cells being damaged is what causes you to feel ill
What type of cell are protists?
Eukaryotic (single-celled) some can be parasites and act as vectors which spread diseases
How do fungi make you ill?
Some fungi are single-celled and others have a body made up of hyphae. These hyphae can grow and penetrate the skin and the surfaces f plants which could produce spores and give other things diseases
What are the 3 ways a pathogen can be spread?
Water - cholera is caused by drinking dirty water
Air - influenza virus is airborne and can be spread when people who have it cough or sneeze via droplets
Direct contact - athlete’s foot is a fungus mostly caused when someone else with it touches the same things with their foot as you do
What is measles?
measles is a viral disease spread by droplets from infected persons sneeze/cough. people who have it have a red skin rash and fever. Measles can sometimes be fatal. Most people are vaccinated
What is HIV?
HIV is a virus spread by sexual contact or the exchange of bodily fluids. The virus attacks the immune system and can’t fight off other infections. Can be controlled using antiretroviral drugs which stop the virus from replicating
What is the Tobacco Mosaic Virus?
A virus which affects plants, leaving a mosaic pattern on the leaves and discoloured and means that they can’t carry out photosynthesis and doesn’t grow well
What are rose black spots?
They are a fungus that causes purple or black spots to develop on leaves on roses, this means less photosynthesis and less growing. It spreads through the environment through water and wind but can be treated using fungicides or stripping the affected leaves
What is malaria?
It’s caused by a protist and half its life cycle happens inside a mosquito. the mosquitos pick it up by eating from an infected animal and pass it on. malaria can be fatal and causes fever
What are some of your body’s defences against pathogens?
The skin which acts as a barrier
Your stomach which has hydrochloric acid
Cilia which waft up mucus which has particles that contain pathogens
What does your immune system produce to destroy pathogens?
White blood cells
What is phagocytosis?
When a white blood cell engulfs foreign cells and digests them
What is unique about every invading pathogen?
the antigen on its surface
What do white blood cells produce to target specific antigens?
Proteins called antibodies which lock onto different antigens and destroy them
How are the trachea and bronchi adapted to defend the body against pathogens?
They secrete mucus which traps particles containing pathogens
What does it mean to get vaccinated?
You have a small amount of dead or inactive pathogens injected into you, these carry antigens which cause your body to produce antibodies and your memory cells remember how and when to make them for when you may get the disease for real and can produce these antibodies rapidly.
What are some pros and cons of vaccinations?
PROS
- have helped control many communicable diseases in the past
- epidemics can be prevented if a large population is vaccinated
CONS
- they don’t always work
- you can sometimes have bad reactions to them
What type of pathogens do antibiotics kill?
Bacteria
Why is it difficult to develop drugs which get rid of viruses?
Because viruses live inside your body cells so it’s difficult to destroy them without destroying your healthy body cells
Why isn’t it good to use antibiotics too much?
because the bacteria may become resistant and reproduce to make more antibiotic-resistant bacteria
