What function does the diaphragm serve in respiration?

The diaphragm serves as the primary muscle of breathing, playing a critical role in the process of inhalation and exhalation. When the diaphragm contracts, it moves downward, creating a negative pressure within the thoracic cavity. This negative pressure allows air to be drawn into the lungs, facilitating the exchange of oxygen and carbon dioxide.

During exhalation, the diaphragm relaxes and moves upward, helping to push air out of the lungs. Its unique dome-shaped structure provides an effective mechanism for expanding and compressing the thoracic cavity, making it essential for normal respiratory function. Understanding the diaphragm's role is fundamental for EMTs, particularly when assessing a patient's respiratory status and providing emergency care.

Other options focus on functions that do not directly describe the main role of the diaphragm in respiration. The diaphragm is not an accessory muscle for coughing, nor does it play a stabilizing role for the rib cage or function primarily as a flexor of the abdominal cavity. Its primary purpose in respiratory mechanics distinctly sets it apart.