Question

select all that apply
choose all events that are associated with inhalation.
□ internal intercostal contracts
□ diaphragm relaxes
□ sternum moves anteriorly
□ diaphragm contracts
□ external intercostals contract

Explanation:

• During inhalation, the diaphragm contracts, moving downward. This increases the volume of the thoracic cavity.
• The external intercostal muscles contract, pulling the ribs upward and outward. The sternum moves anteriorly (forward), also increasing the thoracic cavity volume.
• When the volume of the thoracic cavity increases, the pressure inside the lungs (intrapulmonary pressure) decreases below atmospheric pressure, and air flows into the lungs.
• The internal intercostal muscles contract during forced exhalation, not inhalation.
• When the diaphragm relaxes, it moves upward, which is part of exhalation (decreasing thoracic cavity volume).

Answer:

sternum moves anteriorly, diaphragm contracts, external intercostals contract