Question

Imagine you are a microbe entering the respiratory tract, and describe several protective mechanisms of the respiratory system as well as the track you will take.

Answer 1

Respiratory system begins from the nose and ends in the lungs. It has their own defence mechanism to protect from microbes and other dust particles. extremely small particles like less than 3 to 5 microns of diameter can enter into deep lungs.

Cilia is a tiny muscular hair like projection that lines the airway.it produces a liquid layer of mucus which covers the airway.

The mucus layer traps microorganisms and other particles .the trapped microbes and particles are coughed out, moved to the mouth and swallowed.

Alveolar macrophages, another defence mechanism of the respiratory system are certain white blood cells on the surface of alveoli. The absence of mucus and cilia are due to mucus can slow down the exchange of oxygen and carbon dioxide. However, alveolar macrophages identify foreign particles, bind to them, ingest them and digest. If the threat is severe, additional white blood cells come from circulation like neutrophil to help.

I will enter into the respiratory tract through the nose and then goes to pharynx, larynx, trachea, bronchus, bronchioles and alveolus.