Describe the process of breathing
The diaphragm contracts, moving downwards. The external intercostal muscles contract, and the internal intercostal muscles relax. Pressure in the chest cavity decreases, forcing air into the lungs. The diaphragm relaxes, moving back up. The external intercostal muscles relax and the internal intercostal muscles contract. Pressure in the chest cavity increases, forcing air out of the lungs.
AC
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