nasus /na·sus/ (na´sus) nose.
nose [nōz]
na·sus (n  s s, -zs)n. The nose. |
nose [nōz]
the specialized structure of the face that serves both as the organ of smell and as a means of bringing air into the lungs. (See also Plates.) Air breathed in through the nose is warmed, filtered, and humidified; that breathed through the mouth is not.
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. At the back of the nose these passages lead into the pharynx. The passages also are connected by openings with the paranasal sinuses. One of the functions of the nose is to drain fluids discharged from the sinuses. The nasal cavities also have a connection with the ears by the eustachian tubes, and with the region of the eyes by the nasolacrimal ducts.
The interior of the nose is lined with mucous membrane, and most of the membrane is covered with minute hairlike projections called cilia. Moving in waves these cilia sweep out from the nasal passages the nasal mucus, which may contain pollen, dust, and bacteria from the air. The mucous membrane also acts to warm and moisten the inhaled air.
High in the interior of each nasal cavity is a small area of mucous membrane that is not covered with cilia. In this pea-sized area are located the endings of the nerves of smell, the olfactory receptors. These receptors sort out odors. Unlike the taste buds of the tongue, which distinguish between only four different tastes (salt, sweet, sour, and bitter), the olfactory receptors can detect innumerable different odors. This ability to smell contributes greatly to what we usually think of as taste, because much of what we consider flavor is really odor. (See also smell.)
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. At the back of the nose these passages lead into the pharynx. The passages also are connected by openings with the paranasal sinuses. One of the functions of the nose is to drain fluids discharged from the sinuses. The nasal cavities also have a connection with the ears by the eustachian tubes, and with the region of the eyes by the nasolacrimal ducts.
The interior of the nose is lined with mucous membrane, and most of the membrane is covered with minute hairlike projections called cilia. Moving in waves these cilia sweep out from the nasal passages the nasal mucus, which may contain pollen, dust, and bacteria from the air. The mucous membrane also acts to warm and moisten the inhaled air.
High in the interior of each nasal cavity is a small area of mucous membrane that is not covered with cilia. In this pea-sized area are located the endings of the nerves of smell, the olfactory receptors. These receptors sort out odors. Unlike the taste buds of the tongue, which distinguish between only four different tastes (salt, sweet, sour, and bitter), the olfactory receptors can detect innumerable different odors. This ability to smell contributes greatly to what we usually think of as taste, because much of what we consider flavor is really odor. (See also smell.)
Disorders of the Nose. The mucous membrane of the nose is subject to inflammation; any such inflammation is called rhinitis, which may be caused by the common cold, or by an allergy, particularly hay fever. Nasal polyps may obstruct the nasal passages. Epistaxis, or nosebleed, may be caused by an injury to the nose or may be a symptom of other diseases. The nasal septum may grow irregularly or be deflected to one side by injury; this condition is called deviated septum.
Surgery of the Nose. Nasal surgery is indicated in disorders of the nasal septum, polyps and other growths, and traumatic injury to the structures that interfere with normal nasal breathing. Cosmetic plastic surgery is also done to correct disfigurement that is disturbing to the patient.
Patient Care. Prior to surgery the patient is instructed in the kind of surgery anticipated and is informed of the immediate aftereffects of swelling and discoloration. He is told that the residual swelling may last for several weeks and success of the operation cannot be assessed until after that time.
Immediately after surgery the greatest danger is hemorrhage. If the patient swallows repeatedly or spits up blood, excessive bleeding should be suspected. A Teflon splint or intranasal packing often is used to support the nasal structures and prevent the formation of hematoma, another complication that may develop.
Ice compresses are applied for 24 hours after surgery to reduce swelling and minimize bleeding. The patient is placed in semi-Fowler position during this time.
During convalescence the patient should avoid blowing his nose and picking at crusts. A lubricant may be used to soften the crusts, but no swabs or other objects should be used to clean the nose. A humidifier in the room may help reduce drying and irritation of the mucous membranes during healing.
Immediately after surgery the greatest danger is hemorrhage. If the patient swallows repeatedly or spits up blood, excessive bleeding should be suspected. A Teflon splint or intranasal packing often is used to support the nasal structures and prevent the formation of hematoma, another complication that may develop.
Ice compresses are applied for 24 hours after surgery to reduce swelling and minimize bleeding. The patient is placed in semi-Fowler position during this time.
During convalescence the patient should avoid blowing his nose and picking at crusts. A lubricant may be used to soften the crusts, but no swabs or other objects should be used to clean the nose. A humidifier in the room may help reduce drying and irritation of the mucous membranes during healing.
Nose and related structures.
artificial nose
1. a device placed between the endotracheal tube and the breathing apparatus to trap the heat and humidity in the exhaled gas and use it to warm and humidify subsequently inhaled gas.
2. an electronic system used to monitor and classify odors and gases, consisting of a sensor and a pattern recognition system; called also electric nose.
nasus
[L.] nose.
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