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

Which of the following muscles contract(s) during quiet expiration A: Diaphragm B: Internal intercostals C: External intercostals D: None of the above E: All of the above

When the diaphragm and external intercostals muscles contract, which<br/>of the following actions does NOT occur ____? A: Air moves into the lung B: The intrapleural pressure increases C: The diaphragm moves inferiorly D: The intrapulmonary pressure decreases