Sinus
From Free net encyclopedia
A sinus is a pouch or cavity in any organ or tissue, or an abnormal cavity or passage caused by the destruction of tissue. In common usage, "sinus" usually refers to the paranasal sinuses, which are air cavities in the cranial bones, especially those near the nose and connecting to it.
The term is also applied to a variety of other stuctures in animals, such as:-
- A dilated portion of a blood vein, such as inside the braincase.
- A chronically infected tract such as a passage between an abscess and the skin. It is however distinct from a fistula which is a tract connecting two epithelialised surfaces.
- Another name for the hemocoel, a space in organisms with open circulatory systems filled with hemolymph.
- Another name for the nostril.
- The Sinus node is a structure in the superior part of the right atrium.Template:Anatomy-stub