Question

Find out the protective mechanism of the respiratory system? Explain.

Answer 1

Nose, nasal cavity:

• Small hairs prevent dust and germs from entering the lungs. 
• Dust particles and germs get entangled in the mucus secreted by the mucous membrane. 
• Lysozyme present in the mucous destroys germs. 
• Ciliary cells transport mucus that contains dust and germs to the pharynx and from there to the digestive tract.

Trachea:

• The germs and dust particles get entangled in the mucus secreted by the mucous cells(Goblet cells) and mucus glands seen throughout the tracheal wall. 
• The cilia of ciliary cells in the tracheal wall move the mucus containing dust and germs to pharynx.

Alveoli:

• Macrophages, the specialized cells seen in the alveoli, engulf dust particles and germs.