Question

multiple choice question
inspiration occurs because ________.
o the rib cage moves down and in
a cr ion of a partial vacuum in the bronchioles causes air to enter the lungs
a creation of a partial vacuum in the alveoli causes air to enter the lungs
the diaphragm relaxes and moves up

Explanation:

Inspiration (inhalation) occurs when the diaphragm contracts and moves down, and the rib cage moves up and out. This increases the volume of the thoracic cavity, creating a partial vacuum (lower pressure) in the alveoli (the tiny air - sacs in the lungs). Air then flows from an area of higher pressure (outside the body) to an area of lower pressure (the alveoli).

• The rib cage moving down and in is part of expiration (exhalation).
• A partial vacuum in the bronchioles is not the direct cause of air entering the lungs; it is the alveoli where the gas exchange occurs and the pressure change is relevant for inspiration.
• When the diaphragm relaxes and moves up, it is part of the expiration process.

Answer:

a creation of a partial vacuum in the alveoli causes air to enter the lungs