Question 1:

Which of the following muscles is primarily responsible for the process of inspiration?

Explanation: The primary muscle responsible for inspiration, the process of inhalation, is the diaphragm. When the diaphragm contracts, it flattens and moves downward, increasing the volume of the thoracic cavity and causing air to be drawn into the lungs.

Question 2:

Which of the following muscles is primarily responsible for the process of expiration at rest?

Explanation: The process of expiration at rest is primarily a passive process. The diaphragm relaxes and moves upward, while the elastic recoil of the lungs and chest wall helps push air out of the lungs. No specific muscle contraction is required for expiration at rest.

Question 3:

During forced expiration, which of the following muscles contract to actively decrease the volume of the thoracic cavity?

Explanation: During forced expiration, the abdominal muscles, specifically the rectus abdominis, external obliques, and internal obliques, contract. These muscles exert pressure on the abdominal contents, pushing the diaphragm upward and actively decreasing the volume of the thoracic cavity to expel air from the lungs.

Question 4:

Which of the following describes the process of inhalation?

Explanation: Inhalation, the process of drawing air into the lungs, involves the contraction of the diaphragm and external intercostal muscles. The diaphragm contracts and moves downward, while the external intercostal muscles contract, lifting the ribcage and expanding the thoracic cavity.

Question 5:

What role do the internal intercostal muscles play in breathing?

Explanation: The internal intercostal muscles play a role in forced expiration. During forced expiration, they contract to depress the ribcage and decrease the volume of the thoracic cavity, assisting in the active process of exhaling air from the lungs.