Which dome-shaped muscle under the lungs helps us breathe?

Which dome-shaped muscle under the lungs helps us breathe?

• A. Bronchi
• B. Alveoli
• C. Pleura
• D. Diaphragm

Answer: (D)

Breathing relies on a muscle that changes the size of the chest cavity. The diaphragm is a large, dome-shaped muscle located just below the lungs. When it contracts, it moves downward and flattens, expanding the thoracic cavity and creating a negative pressure that draws air into the lungs. When it relaxes, it moves upward, helping to push air out as the lungs recoil. This makes the diaphragm the primary muscle involved in inspiration. The other options are not muscles: the bronchi are airways that conduct air into the lungs; the alveoli are tiny air sacs where gas exchange happens; and the pleura are membranes surrounding the lungs and lining the chest cavity.

Breathing relies on a muscle that changes the size of the chest cavity. The diaphragm is a large, dome-shaped muscle located just below the lungs. When it contracts, it moves downward and flattens, expanding the thoracic cavity and creating a negative pressure that draws air into the lungs. When it relaxes, it moves upward, helping to push air out as the lungs recoil. This makes the diaphragm the primary muscle involved in inspiration.

The other options are not muscles: the bronchi are airways that conduct air into the lungs; the alveoli are tiny air sacs where gas exchange happens; and the pleura are membranes surrounding the lungs and lining the chest cavity.