Saunders Respiratory Practice 2025 – 400 Free Practice Questions to Pass the Exam

The main function of the diaphragm during breathing is to assist in changing lung volume. The diaphragm is a dome-shaped muscle located beneath the lungs, and its contraction and relaxation play a crucial role in the respiratory process. When the diaphragm contracts, it moves downward, creating a negative pressure in the thoracic cavity. This negative pressure draws air into the lungs, increasing lung volume. Conversely, when the diaphragm relaxes, it moves upward, decreasing lung volume and pushing air out of the lungs. This fundamental action is essential for effective inhalation and exhalation, making the diaphragm a key player in the mechanics of breathing.

The other options do not accurately describe the primary role of the diaphragm in respiration. Sound production involves the vocal cords rather than the diaphragm, and while digestion is an essential bodily function, it is not directly related to the diaphragm's role in breathing. Filtering air particles primarily occurs in the nasal passages and the respiratory tract, not through the diaphragm's actions.