Collapsed Lung, Pneumothorax

A collapsed lung, or pneumothorax, occurs when all or part of a lung collapses or caves inward. This occurs when air gets in the area between the lung and chest wall. When this happens the lung cannot fill up with air, breathing becomes hard, and the body gets less oxygen. A collapsed lung can occur spontaneously in a healthy person or in someone who has lungs compromised by trauma, asthma, bronchitis, or emphysema.

Epiglottis

The epiglottis is flap of cartilage located in the throat behind the tongue and in front of the larynx. The epiglottis is usually upright at rest allowing air to pass into the larynx and lungs. When a person swallows the epiglottis folds backward to cover the entrance of the larynx so food and liquid do not enter the windpipe and lungs. After swallowing the epiglottis returns to its original upright position.

Breathing

Breathing consists of two phases. The first phase is the inspiration phase. Inspiration allows air to flow into the lungs. The second phase is expiration. Expiration involves gases leaving the lungs. During inspiration, the diaphragm and intercostal muscles contract allowing air to enter the lungs. During expiration, the inspiration muscles relax forcing gases to flow out of the lungs.