P1 4.3.1. Communicable diseases 2 (will come up) Flashcards
How does the skin protect against pathogens
Acts as a barrier to pathogens
Secretes antimicrobial substances which kill pathogens
How does the nose prevent pathogens
The hair and mucus trap particles that could contain pathogens
How does the stomach kill pathogens
It produces hydrochloric acid which kills pathogens
How do the trachea and bronchi prevent pathogens causing infection
They are lined with cilia which waft mucus up to the back of the throat to where it can be swallowed
What does the immune system do
Destroy pathogens that make it into your body
What do phagocytes do
The white blood cells engulf foreign cells and digest them
Why do white blood cells produce antitoxins
To counteract toxins produced by the invading bacteria
What do lymphocytes do
Every invading pathogen has unique antigens on its surface
When your white blood cells come across a foreign antigen they will produce proteins called antibodies which lock onto the invading cells so that they can be found and destroyed by other white blood cells
How do vaccines work
It involves injecting small amounts of dead or inactive pathogens
They carry antigens which cause your white blood cells to attack them and produce antibodies
If the same pathogen re-enters the body the white blood cells respond quickly to produce the correct antibodies, preventing infection
Pros of vaccines
Helped control lots of infectious diseases that were once common in the UK (measles, polio, mumps, rubella)
Epidemics can be prevented if a large percentage of the population is vaccinated, even the people who aren’t vaccinated are unlikely to catch the disease as there are fewer people who can pass it on
Cons of vaccines
Vaccines don’t always work (sometimes they don’t give you immunity)
You can sometimes have a bad reaction to a vaccine (eg swelling or sometimes fever and seizures) They are very rare however
