General Defence system

Question 1

How do our eyes protect us?

Answer 1

They produce tears which are slightly antiseptic.

Question 2

How do our ears protect us?

Answer 2

Wax is produced and pushed along the ear canal by tiny cilia, taking any foreign bodies with it.

Question 3

How does our skin protect us?

Answer 3

• It produces sweat which is slightly antiseptic.
• It covers our body and acts as a barrier. Prevents bacteria and viruses reaching the tissues beneath. If the barrier is broken platelets form a scab stopping pathogens getting in and stopping you from bleeding to death.
• Healthy skin is covered with microorganisms that help keep you healthy and act as an extra barrier.
• It produces antimicrobial secretions to destroy pathogenic bacteria.

Question 4

How does our nose protect us?

Answer 4

It is full of hairs and produces a sticky liquid called mucus. The hair and mucus trap particles in the air that may contain pathogens or irritate your lungs.

Question 5

How do our trachea and bronchi protect us?

Answer 5

They secrete mucus that traps pathogens from the air. The lining of the tubes is covered in cilia. The cilia beat to waft the mucus up to the back of the throat where it is swallowed.

Question 6

What are cilia?

Answer 6

Tiny hair-like projections from the cells.