Final answer:
The correct sequential order of structures that air passes through upon inhalation is: pharynx → larynx → trachea → bronchi → bronchioles, concluding in the alveoli for gas exchange.
Step-by-step explanation:
In the process of inhalation, air follows a specific pathway through various anatomical structures. After passing through the nasal cavity, air reaches the pharynx, then travels to the larynx, which is often referred to as the voice box. From the larynx, air moves into the trachea, commonly known as the windpipe. The trachea then divides into the right and left bronchi. Each bronchus enters a lung, where it subdivides into smaller passages called bronchioles. The bronchioles end in tiny air sacs named alveoli, which are the sites for gas exchange between the air and the blood.
Identification of W, X, Y, and Z in the context provided: W - (a) Trachea, X - (b) Bronchus, Y - (c) Bronchiole, Z - (d) Larynx. The correct order in which inhaled air travels from the pharynx to the bronchioles is: pharynx → larynx → trachea → bronchi → bronchioles.