Question

If you arrange the following structures in the order in which they could be passed by an O₂ during inspiration, what would be the order?
(I) Bronchioles
(II) Trachea
(III) Alveolus
(IV) Pharynx

• A. (I), (II), (III), (IV)
• B. (IV), (II), (I), (III)
• C. (II), (I), (III), (IV)
• D. (IV), (III), (II), (I)

Answer 1

The correct option is B

(IV), (II), (I), (III)

The correct answer is option (B)

Explanation of the correct answer:

1. The correct order of structures in which they could be passed by oxygen during inspiration is: Pharynx, Trachea, Bronchioles, and Alveolus.
2. The pharynx is the common passage for food and air and is present behind the mouth, nose, and larynx.
3. The trachea, also known as the windpipe, functions as the airway and connects the larynx to the bronchi of the lungs.
4. Bronchioles are the pathways that are formed due to the branching of bronchi in the lungs.
5. The alveolus is a cup-shaped structure that provides the site of gaseous exchange between the lungs and the blood.

Explanation for the incorrect options:

Options (A), (C), and (D):

1. The correct order of structures in which they could be passed by oxygen during inspiration is: Pharynx, Trachea, Bronchioles, and Alveolus.

Final answer: The correct order of structures in which they could be passed by oxygen during inspiration is: Pharynx, Trachea, Bronchioles, and Alveolus.