What are the nasal cavity and sinuses?
The external nose opens into the nasal cavity or breathing passage. The nasal cavity runs above the hard and soft palate (the roof of your mouth). It connects with the back of the throat in an area called the nasopharynx. Four paired groups of sinuses surround the nose. The sinuses are hollow cavities that help humidify, warm and filter the air we breathe. The nasal cavity opens into the frontal sinuses beneath the forehead, the maxillary sinuses behind the cheeks, the ethmoid sinuses between the eyes, and the sphenoid sinuses deep behind the nose at the center of the skull. The nasal cavity and sinuses are made up of a variety of cell types. These include the mucus producing cells and minor salivary gland cells, epithelial cells which make up most of the lining of the nose and sinuses, nerve cells for smell and sensation, and cells that make up blood vessels and lymphatic channels. All of these cell types can develop into benign or malignant tumors.
