Answers. Best Answer: FL means Flight Level. It's used above 18.000ft (in the US, in other countries other altitudes are used as the boundary) to indicate the altitude in hundreds of feet. So FL230 is 23.000ft standard altitude.est Answer: FL means Flight Level. It's used above 18.000ft (in the US, in other countries other altitudes are used as the boundary) to indicate the altitude in hundreds of feet.
The nostrils, which form the external entrance of the nose, lead into the two nasal cavities, which are separated from each other by the nasal septum, a partition formed of cartilage and bone. Three bony ridges project from the outer wall of each nasal cavity and partially divide the cavity into three air passages.
Nasal conchae definition. Each of the two narrow, curled, spongy bones protruding from the nasal cavity walls in the human nose is referred to as nasal concha or nasal turbinate. Covered in thick mucus membrane, the nasal conchae are responsible for regulating the airflow through the nasal passages.