Question

The beating of the cilia of the respiratory passages in the direction of the pharynx forms a ________.

a) Mucociliary escalator
b) Respiratory tree
c) Bronchial circuit
d) Pleural membrane

Answer 1

The beating of cilia in the respiratory passages moves mucus and trapped debris towards the pharynx in a process known as the mucociliary escalator, an important defense mechanism of the respiratory system.

Step-by-step explanation:

The beating of the cilia in the respiratory passages propels mucus and trapped debris towards the pharynx, forming a protective mechanism known as the mucociliary escalator. This process is a crucial aspect of the respiratory system's defense, where mucus produced by goblet cells traps particles and pathogens. The cilia then continuously beat to move this mucus, along with the trapped contents, upwards toward the throat, where it can be swallowed and destroyed by the acidic environment in the stomach.