During vigorous exercise, expiration becomes an active process known as forced expiration. Which option correctly describes the muscular actions and structural changes that occur during forced expiration?
The external intercostal muscles contract, pulling the rib cage up and out, while the internal intercostal muscles relax and the diaphragm relaxes.
The internal intercostal muscles relax, the external intercostal muscles contract, and the diaphragm contracts to flatten, decreasing thoracic volume.
The internal intercostal muscles contract, pulling the rib cage down and in, while the external intercostal muscles relax and the diaphragm relaxes.
Both the internal and external intercostal muscles contract simultaneously, pulling the rib cage downwards and inwards, while the diaphragm flattens.
