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nose,olfactory and respiratory organ, located between the eyes. The external nose, composed of bone and cartilage, is the most prominent feature of the face in humans. The internal nose is a hollow structure above the roof of the mouth, divided by the septum into two nasal cavities that extend from the nostrils to the pharynxpharynx
, area of the gastrointestinal and respiratory tracts which lies between the mouth and the esophagus. In humans, the pharynx is a cone-shaped tube about 4 1-2 in. (11.43 cm) long.
..... Click the link for more information. . The mucous membrane that lines the nasal cavities is covered with fine hairs known as cilia that help to filter dust and impurities from the air before it reaches the lungs; the air is also moistened as it passes over the sticky nasal membrane. In the human nose, there are three horizontal folds on the walls of the nasal cavities, called the conchae: other mammals may have more conchae. The uppermost concha is densely supplied with capillaries that warm the air passing over them to near body temperature. High in the nasal cavity is a small tract of mucous membrane containing the nerve cell endings of the olfactory nerve, which impart the sense of smell. Therefore, inflammation of the nasal mucous membranes, which commonly accompanies colds and other infections, not only obstructs breathing but also impairs the sense of smell.
the initial portion of the respiratory tract in vertebrate animals and in man. The nose contains the organs of smell and fulfills a protective function; it also acts as a resonator during phonation.
Located in the middle third of the visceral cranium, the nose consists of a surface portion and a nasal cavity. In man the nasal cavity is bounded by the bones of the visceral and partly the cerebral cranium; the anterior section is bounded by cartilage. The nasal cavity borders superiorly with the cranial cavity, laterally with the eye sockets, and inferiorly with the oral cavity. The anterior division of the nose opens through paired orifices, called nostrils, or nares. The nasal septum, consisting of the vomer, of cartilage, and of the vertical plate of the ethmoid bone, divides the nasal cavity into right and left halves, which open posteriorly to the nasopharynx through oval choanae. Both exterior walls of the nasal cavity contain three conchae, which divide the nasal cavity into superior, middle, and inferior nasal meatuses. The nasal cavity communicates with several air-filled cavities: the maxillary sinus, or antrum of Highmore, in the maxilla; the frontal sinus in the frontal bone; and the alveoli of the labyrinths of the ethmoid bone. The nasolacrimal canal opens into the anterior portion of the inferior nasal meatus. The nasal cavity consists of an olfactory portion and a respiratory portion. The olfactory receptors—the receiving apparatus of the olfactory analyzer—consist of neurons that are embedded in a layer of sensitive epithelium. This layer covers the mucous membrane of the superior nasal meatus, the neighboring, membranous part of the nasal septum, and the superior portion of the middle nasal concha.
The mucous membrane of the respiratory region is covered with ciliated epithelium, contains a large number of glands, and is rich in blood vessels that anastamose to form the cavernous plexuses of the nasal conchae. The walls of the vessels in the cavernous tissue of the conchae are especially rich in smooth-muscle and elastic fibers, which accounts for the ability of the cavernous tissue to rapidly swell and recede under the influence of various chemical, thermal, and nervous stimuli. When inhalation occurs through the nose, the air is slightly warmed, cleansed of dust and microorganisms, and humidified. Otorhinolaryn-gology is the branch of medicine that treats diseases of the nose.
In man, the external shape of the nose is anthropologically significant. The width of the nose varies greatly among modern racial groups. The shape is expressed by the nasal index—the ratio of the width of the nose to the height, expressed as a percentage. Three categories exist: a ratio of up to 69.9 percent results in leptorrhiny; 70.0–84.9 percent, in mesorrhiny; and 85.0–99.9 percent, in chamaerrhiny. Leptorrhiny is most characteristic of the Caucasoid race, while chamaerrhiny is mostly found in the equatorial race. The nasal index can also be determined on the skull by measuring the width of the piriform opening. The shape of the ridge of the nose can be described either by separate references to the bony and cartilaginous sections or by a single descriptive reference to the shape as a whole—concave, straight, convex, or undulate.
The height of the tip of the nose above the facial plane and the height of the bridge of the nose are important racial features. The angle of protrusion of the nasal bones is also measured on the skull. In groups of the equatorial race, nasal protrusion is slight and the bridge of the nose is usually low. In Caucasoids and American Indians, the nose protrudes greatly and the bridge is high. The remaining races occupy an intermediate position with respect to these characteristics. Other valuable anthropometric criteria are the positions of the tip and base of the nose, which can be raised, straight, or lowered, and the orientation of the narial axes, which can be transverse or sagittal.
What does it mean when you dream about a nose?
The nose is a source of much energy and wisdom. Having “a nose for the news” or “sticking one’s nose into someone else’s business” can be important messages for the dreamer to heed. A nosey neighbor or business associate may be sticking their nose into your personal life. Or the dreamer may be “brown nosing” too much at the job or in some other arena of life.