Which combination of breathing activities describes inhalation?

Inhalation is the process of bringing air into the lungs, and it involves specific movements of the diaphragm and ribcage. When we inhale, the diaphragm contracts and moves downward, while the ribs elevate, creating a larger thoracic cavity. This expansion decreases the pressure inside the lungs relative to the outside atmosphere, allowing air to rush in.

The correct combination describes the diaphragm being lowered, the ribs being raised, and air being taken in. This accurately represents the mechanics of inhalation. The contraction of the diaphragm and the elevation of the ribs work together to facilitate this process.

Other combinations do not accurately reflect the physical actions associated with inhalation. For instance, a raised diaphragm suggests that the muscle is relaxed, which does not occur during inhalation. Similarly, if the ribs were lowered during inhalation, it would impede the ability to draw in air effectively. Thus, the correct answer encapsulates the fundamental physiological movements that occur during inhalation.