How is air forced out of your lungs?

Air is forced out of the lungs primarily through the contraction of the diaphragm and intercostal muscles. When these muscles relax, the diaphragm moves upward, causing the thoracic cavity to decrease in volume. This increase in pressure within the lungs pushes air out through the trachea and into the environment. Additionally, abdominal muscles can aid in expelling air more forcefully during activities like coughing or vigorous exhalation.