19/3 physical and chemical body defences Flashcards
(5 cards)
1
Q
What do physical barriers do?
A
Stop pathogens getting past them, or make it very difficult to do so
2
Q
What do chemical barriers do?
A
React with substances in the pathogens and either make them inactive or kill then
3
Q
Why does smoking increase the risk of lung infections?
A
The smoke damages the ciliated cells which carry pathogens outside the body
4
Q
Name some body defences
A
Ciliated cells
Mucus
Skin
Hydrochloric acid
Lysozyme
5
Q
What is a lysozyme, where is it found and what does it do?
A
Enzyme
Found in skin, tears, saliva and mucus
Reacts with pathogens to kill or deactivate them
