6. Which of the following statements correctly describes what happens to the diaphragm during an

inhalation, when the lungs inflate?

O A. The diaphragm returns to its resting state.

O B. The diaphragm contracts and flattens.

O C. The diaphragm only moves during exhale.

O D. The diaphragm expands.

O B. The diaphragm contracts and flattens.

Explanation:

The diaphragm is a skeletal striated muscle that separates the abdominal cavity from the thoracic cavity, has a dome shape and plays a key role in breathing. Locate near the lumbar vertebrae, the lower ribs and the sternum and can be divided according to its location into three parts: sternal, costal and lumbar.

During inhalation, the diaphragm contracts and flattens, reducing the pressure inside the chest and compressing the viscera of the abdomen, which facilitates the entry of air into the lungs.

At the expiration, the inverse process occurs: it relaxes and rises, increasing the pressure inside the chest and expelling air from the lungs.

Answer is B.

As the diaphragm contracts and flattens, it increases the volume of the thorax where the lungs are located. This results in a decrease in pressure (Boyle's Law, if you know it) that creates a pressure gradient from outside to inside. This is what causes air to move into the lungs.