In the topic of muscles used to breathe, which movements occur during inhalation vs exhalation: diaphragm relaxes, intercostal muscles relax, diaphragm contracts, intercostal muscles contract?

What this table is testing

You are matching each muscle action to whether it helps air move into the lungs (inhalation) or out of the lungs (exhalation).

Linking muscle action to chest volume

• When the diaphragm contracts, it flattens and moves down, which increases chest volume.
• When the intercostal muscles contract (the external intercostals in normal breathing), the ribs move up and out, which increases chest volume.
• When these muscles relax, the chest returns to its resting position, chest volume decreases, and air is pushed out.

Filling in each row

• Diaphragm relaxes: Exhalation
• Intercostal muscles relax: Exhalation
• Diaphragm contracts: Inhalation
• Intercostal muscles contract: Inhalation

Quick check using pressure

Increasing volume lowers pressure in the lungs, so air moves in; decreasing volume raises pressure, so air moves out.