B5.9 - Human Defence Responses (Finished) Flashcards
How does the skin prevent pathogens from reaching the tissue beneath? (3 things)
- The skin acts as a barrier
- The skin secretes antimicrobial substances that kill pathogens
- Healthy skin is covered with microorganisms that act as a natural barrier
How do platelets help defend against disease?
If you bleed, the platelets in your blood set up a chain of events that forms a clot, drying into a scab which stops pathogens from getting in
What do the trachea and bronchi do to defend against disease?
The trachea and bronchi secrete mucus that traps pathogens from the air. The lining is covered in cilia that sway to beat the mucus back up to the throat to be swallowed
What in your nose defends against pathogens coming in?
The nose is full of hairs that produce mucus which traps particles in the air that may contain pathogens
What are the three roles of white blood cells?
- consuming pathogens
- producing antibodies
- producing antitoxins
How do some white blood cells ‘consume’ pathogens?
They ingest (take in) pathogens, digesting and destroying them so they can!t make you feel ill
What do antitoxins produced by white blood cells do?
Antitoxins produced by white blood cells counteract toxins produced by bacterium
How do antibodies work?
Every invading pathogen has unique molecules (antigens) on its surface. Antibodies lock onto invading cells specific antigens so they can be easily found and destroyed by other white blood cells
When do white blood cells produce antigens?
When white blood cells come across a foreign antigen they start to produce proteins called antibodies. They are then produced rapidly and carried around the body to produce a similar type of cell
Why do people become immune to pathogens?
If the same pathogen attacks again, the white blood cells will rapidly produce the known antibodies to kill it
