Human defence systems (AQA GCSE Biology Combined Science): Flashcards

Protect from pathogens; work against all types, first line of defence

Tears, saliva, and mucus

Kills bacteria by breaking down their cell walls

Kills pathogens in food/drink via very acidic environment

Too thick for most pathogens to get through

Tiny hair-like structures that move in wave-like motion

Sweep mucus and trapped pathogens up to throat to swallow

Kill harmful bacteria, compete for nutrients, take up space

Kill pathogenic bacteria or stop them from growing

Paralyses cilia so they can't sweep mucus/bacteria out of lungs