4.3.1.6 Human Defence Systems Flashcards
1
Q
What are the human bodies defences?
A
- skin
- hairs and mucus
- trachea and bronchi
- stomach
2
Q
How does the skin help to defend the body against pathogens?
A
- acts as a barrier
- secretes antimicrobial substances that kill pathogens
3
Q
How does the hairs and mucus in your nose help to defend the body against pathogens?
A
- trap particles that could contain pathogens
4
Q
How does the trachea and bronchi help to defend the body against pathogens?
A
- secrete mucus to trap pathogens
5
Q
How does the cilia on the trachea and bronchi help to defend the body against pathogens?
A
- hair-like structures
- waft the mucus up to back of throat where it can be swallowed
6
Q
How does the stomach help to defend the body against pathogens?
A
- produces hydrochloric acid which kills pathogens
7
Q
What is the most important part of the immune system?
A
- white blood celsl
8
Q
What is phagocytosis?
A
- white blood cells engulfing foreign cells and digesting them
9
Q
What are antigens?
A
- unique molecules on a pathogens surface
10
Q
What does a lymphocytes do when it comes across a foreign antigen?
A
- will start to produce proteins called antibodies to lock onto invading cells so that they can be found and destroyed by other lymphocytes
- antibodies produced are specific
- antibodies produced rapidly and find all similar bacteria/viruses
11
Q
What happens if a person is infected with the same pathogen again?
A
- lymphocytes rapidly produce antibodies to kill it
11
Q
What are antitoxins?
A
- toxins that counteract toxins produced by invading bacteria
