The nose can be thought of as a tunnel with an opening on the face and an opening at the top of the throat. The tunnel is called the nasal cavity. The nasal cavity is divided into a right and a left side by a bony and cartilaginous divider called the nasal septum. Towards the front of the nose the septum is constructed primarily of cartilage but in its back is primarily bone. The top of the nasal cavity is divided from the anterior cranial cavity by a bone called the cribiform plate. The lateral walls abut on either side with the maxillary bones also known as the cheek bones. The floor of the nasal cavity is separated from the top of the mouth by the palatal bones.
All the nasal cavity bony surfaces are lined by tissue called mucosa. This mucosa contains blood vessels, nerves, and small glands (these glands secrete fluids into the nasal cavity). The mucosa supports small hair-like projections called cilia. These cilia carry the mucous blanket from the front of your nose to the back, and from the sinuses out into the nose, and then into the back of your nose from whence the mucous is swallowed. This is a very complex and important function. It is called the mucociliary transport system, and is the key to a healthy nose. Protruding into the nasal cavity on either side are three small bones called turbinates and as you will learn under the section on physiology, these act as air conditioners and filters for normal respiration. At the very top of the nose the nerves responsible for conducting information about smell enter into the nasal cavity through a series of very small holes in the cribiform plate. On the nasal cavity side of the cribiform plate is a very special mucosal lining called olfactory epithelium. It is here that the sensory cells for smell detect the various odors, and it is here that these cells form the nerves that then course through the cribiform plate to the olfactory centers within the brain. The nose is also supplied by nerves capable of detecting pain, temperature and pressure. These are called sensory nerves. The main sensory nerve supplying the nasal cavity is the trigeminal nerve.
Contained within the facial bones and surrounding the nasal cavity are a system of air cells called paranasal sinuses. The paranasal sinuses include the maxillary sinuses, the ethmoid sinuses, the sphenoid sinus, and the frontal sinuses. The sinuses are all lined by the same mucosa that lines the nasal cavity. The paranasal sinuses all communicate with the nasal cavity by a series of small holes called ostia.
Taste is a sense different from smell. The sense of taste lies primarily in the mouth and predominantly on the tongue. The information from the taste buds is predominantly transmitted to the brain in a nerve called the facial nerve. The facial nerve is distinct from the olfactory nerve. Some of the taste information is also transmitted in the glossopharyngeal and the vagal nerves. Sensory input to the mouth and throat is carried in the trigeminal, glossopharyngeal, and vagal nerves.
Please accept our apologies for the complexity, but this is the simplest we could make it.