gas exchange Reference Libraries
The lung is a vital organ that is a part of the respiratory system. Generally a person has two lungs; however, the body can function with only one. The lung’s main function is to move oxygen and carbon dioxide into and out of the bloodstream through gas exchange. The lungs are located lateral to the heart in the thoracic cavity. Each lung has a tip called the apex, which is superior in the...
- The navel or umbilicus.
- In Greek archaeology: A central boss, as on a shield, a bowl, etc.
- A sacred stone in the temple of Apollo at Delphi, believed by the Greeks to mark the 'navel' or exact center-point of the earth.