What happens to the diaphragm during inhalation?

• A. The diaphragm contracts and moves downward.
• B. The diaphragm contracts and moves upward.
• C. The diaphragm relaxes and moves downward.
• D. The diaphragm relaxes and moves upward.

Answer: (A)

Verified step by step guidance

1. Understand the role of the diaphragm in the respiratory process. The diaphragm is a dome-shaped muscle located at the base of the lungs, playing a crucial role in breathing.
2. During inhalation, the diaphragm contracts. This contraction is an active process that requires energy, causing the diaphragm to flatten and move downward.
3. As the diaphragm moves downward, it increases the volume of the thoracic cavity. This increase in volume leads to a decrease in pressure inside the thoracic cavity compared to the outside atmosphere.
4. The decrease in pressure within the thoracic cavity creates a pressure gradient, causing air to flow into the lungs to equalize the pressure. This is how inhalation occurs.
5. Recognize that the movement of the diaphragm downward during contraction is essential for drawing air into the lungs, facilitating the process of inhalation.