• 2022-06-01
    In order to inhale, the size of the thoracic cavity has to increase in order to decrease the internal pressure (compared to atmospheric pressure). In order to accomplish this task, which of the following must occur?
    A: the diaphragm muscle relaxes and the external intercostals contract
    B: the diaphragm muscle contracts and the external intercostals relax
    C: the diaphragm muscle and external intercostals contract
    D: the diaphragm muscle and external intercostals relax