Final answer:
Exhalation, or expiration, is a passive process where the diaphragm relaxes, leading to an increase in air pressure in the lungs, which forces air out.
Step-by-step explanation:
The Process of Exhalation
The nurse at the community center taught that the process of expiration, also known as exhalation, is typically a passive process that contrasts with the active process of inhalation. During expiration, the diaphragmrelaxes and moves upward, causing the thoracic cavity to decrease in volume which leads to an increase in air pressure within the lungs. This increase in pressure forces the air out of the lungs, much like how air is released from a balloon. In situations where exhalation is forced, such as during vigorous activities or coughing, muscles including the internal intercostal and abdominal muscles can actively assist in expelling air.