ear

ear,

organ of hearing and equilibrium. The human ear consists of outer, middle, and inner parts. The outer ear is the visible portion; it includes the skin-covered flap of cartilage known as the auricle, or pinna, and the opening (auditory canal) leading to the eardrum (tympanic membrane).

The middle ear, separated from the outer ear by the eardrum, contains three small bones, or ossicles. Because of their shapes, these bones are known as the hammer (malleus), anvil (incus), and stirrup (stapes). Air reaches the middle ear through the Eustachian tubeEustachian tube
[for Bartolomeo Eustachi], a hollow structure of bone and cartilage extending from the middle ear to the rear of the throat, or pharynx, technically known as the pharyngotympanic or auditory tube.
..... Click the link for more information. , or auditory tube, which connects it to the throat.

The inner ear, or labyrinth, contains the cochlea, which houses the sound-analyzing cells of the ear, and the vestibule, which houses the organs of equilibrium. The cochlea is a coiled, fluid-filled tube divided into the three canals: the vestibular, tympanic, and cochlear canals. The basilar membrane forms a partition between the cochlear canal and the tympanic canal and houses the organ of Corti. Anchored in the Corti structure are some 20,000 hair cells, with filaments varying in length in a manner somewhat analogous to harp strings. These are the sensory hearing cells, connected at their base with the auditory nerve.

The Hearing Process

In the course of hearing, sound waves enter the auditory canal and strike the eardrum, causing it to vibrate. The sound waves are concentrated by passing from a relatively large area (the eardrum) through the ossicles to a relatively small opening leading to the inner ear. Here the stirrup vibrates, setting in motion the fluid of the cochlea. The alternating changes of pressure agitate the basilar membrane on which the organ of Corti rests, moving the hair cells. This movement stimulates the sensory hair cells to send impulses along the auditory nerve to the brain.

It is not known how the brain distinguishes high-pitched from low-pitched sounds. One theory proposes that the sensation of pitch is dependent on which area of the basilar membrane is made to vibrate. How the brain distinguishes between loud and soft sounds is also not understood, though some scientists believe that loudness is determined by the intensity of vibration of the basilar membrane.

In a small portion of normal hearing, sound waves are transmitted directly to the inner ear by causing the bones of the skull to vibrate, i.e., the auditory canal and the middle ear are bypassed. This kind of hearing, called bone conduction, is utilized in compensating for certain kinds of deafness (see deafnessdeafness,
partial or total lack of hearing. It may be present at birth (congenital) or may be acquired at any age thereafter. A person who cannot detect sound at an amplitude of 20 decibels in a frequency range of from 800 to 1,800 vibrations per second is said to be hard of
..... Click the link for more information. ; hearing aidhearing aid,
device used in some forms of deafness to amplify sound before it reaches the auditory organs. Modern hearing aids are electronic. They contain a tiny receiver and a transistor amplifier, and are usually battery powered.
..... Click the link for more information. ), and plays a role in the hearing of extremely loud sounds.

Balance and Orientation

In addition to the structures used for hearing, the inner ear contains the semicircular canals and the utriculus and sacculus, the chief organs of balance and orientation. There are three fluid-filled semicircular canals: two determine vertical body movement such as falling or jumping, while the third determines horizontal movements like rotation. Each canal contains an area at its base, called the ampulla, that houses sensory hair cells. The hair cells project into a thick, gelatinous mass. When the head is moved, the canals move also, but the thick fluid lags behind, and the hair cells are bent by being driven through the relatively stationary fluid. As in the cochlea, the sensory hair cells stimulate nerve impulses to the brain. The sensory hair cells of the saclike utriculus and sacculus project into a gelatinous material that contains lime crystals. When the head is tilted in various positions, the gelatin and crystals exert varying pressure on the sensory cells, which in turn send varying patterns of stimulation to the brain. The utriculus sends indications of the position of the head to the brain and detects stopping and starting. The utriculus and sacculus also help control blood flow to the brain.

Disorders of the Ear

One of the most common ear diseases is known as otitis media, a middle ear disorder. Most common among young children, otitis media probably results from Eustachian tubes that are shorter and more horizontal than in adults, allowing infection to spread and preventing fluids in the middle ear from draining. It can bring about permanent hearing loss, although modern medication is generally able to clear up the disease. Serious cases may require drainage of collected fluids through an incision in the eardrum or insertion of a tiny drainage tube. Other ear diseases include otosclerosis, involving excessive bone growth in the middle ear, and presbycusis, the progressive decay of the inner ear's hearing nerve.

Ear (vertebrate)

The organ which sends information about sound to the brain, constituting the sense of hearing, as well as vestibular information about the orientation of the head in space. The vertebrate ear is generally divided into three regions that have discrete functions: The inner ear is found in all vertebrates, and it subsumes both hearing and balance (functions). The external ear and the middle ear, not found in all vertebrates, enhance hearing. See Hearing (vertebrate)

Ear structure

The inner ear is embedded in the ear (or otic) capsule and has a common embryological development in all vertebrate groups. In comparing the inner ears of different vertebrates, the major structural differences are associated with the auditory part of the ear. With few exceptions, the vestibular portion of the inner ear is developmentally, structurally, and functionally nearly the same in all vertebrates.

The middle ear and external ear are not found in the fishes. All tetrapods (amphibians, reptiles, birds, and mammals) have a middle ear with a tympanic membrane. Reptiles, birds, and mammals also have an external auditory meatus (or canal) which extends from the tympanic membrane to the external surface of the head. Mammals generally have an external structure, the pinna, that helps “collect” and carry the sound to the ear canal and then to the tympanum. The major difference in the middle ear among tetrapods is that it has a single ear bone, or ossicle (often called the columella or stapes), in amphibians, reptiles, and birds, while mammals have three middle-ear bones (malleus, incus, and stapes).

The basic sensory unit in the inner ear is the sensory hair cell. These specialized cells are morphologically similar in all of the epithelial structures of the ear in all vertebrates (and in the lateral line of fishes and amphibians), but they may have either auditory or vestibular functions depending upon the associated superstructure. The superstructure serves to facilitate the transmission of vibrations from the environment to the hair cells. For the vestibular apparatus, the superstructure blocks external vibratory energy, but sensitizes the sensory hair cells to the pull of gravity and to acceleratory and deceleratory movements of the head. See Lateral line system

The sensory hair cell is a columnar, polarized structure from whose apex extend thin cilia that resemble hairs. Each hair cell has many such cilia, making up a ciliary bundle which bends in response to motional energy. The cilia in each bundle include many stereocilia and a single, eccentrically positioned kinocilium. The cilia extend into an extracellular fluid-filled space, with their tips embedded in a gelatinous membrane. See Cilia and flagella

The sensory hair cell is the detector of motion, either produced by compression and rarefaction of molecules due to sound waves, or imparted by movement of the head against gravity. This motion produces bending of the ciliary bundles, and this in turn results in a change in configuration of the membrane overlying the stereocilia and opening of channels in the membrane. It is generally thought that these channels admit calcium into the cell, and this in turn interacts with other components of the cell. Ultimately, the energy generated by these interactions causes release of neurotransmitter at the base of the cell, and results in stimulation of afferent neurons which contact the cell. See Neurobiology, Synaptic transmission

Fishes

In elasmobranchs and bony fishes the inner ear is located in the brain (cranial) cavity somewhat behind the eye. The inner ear has several regions, including three semicircular canals and otolith organs. Other than the very primitive jawless fishes which have one or two semicircular canals, all other vertebrates have three canals. All fishes, amphibians, reptiles, and birds have three otolith organs—the saccule, utricle, and lagena—while mammals do not have the lagena (Fig. 1).

Left-ear external view of the membranous labyrinths of (a) teleost, (b) frog, (c) bird, and (d) mammal

At one end of each endolymph-filled semicircular canal is a widened area, the ampulla, which has a sensory area called the crista (or crista ampullaris). The crista contains large numbers of sensory hair cells, as well as other cells which provide support for the hair cells. At the base of the hair cells are nerve endings from the vestibular branch of the eighth cranial nerve. Each of the otolith organs also has a sensory area, called a macula, that contains hair cells and supporting cells. The cilia of the otolithic organs are embedded in a thin gelatinous membrane that also contains very dense calcium carbonate crystals. In elasmobranchs, primitive fishes, and all tetrapods, these crystals are called otoconia. In most bony fishes the crystals are fused into a single mass in each otolith organ called the otolith.

Fishes are able to detect a wide range of sound using their inner ear. Tetrapods detect sounds that impinge on the tympanic membrane and then are carried by the middle-ear bones to the inner ear, where the sounds set the fluids of the ear into motion and thus stimulate the sensory hair cells. In fishes, however, this kind of pathway is not needed since sound is already traveling through water. Indeed, since the fish's body is the same density as that of water, sound would travel right through the fish were it not for the otoconia or otoliths. Since these structures are much denser than the fish's body and the water, they stay still while the fish's body and the attached sensory hair cells move with the sound field. Since the stereocilia are attached to both the top of the hair cells and to the otoconia or otolith, they are bent as their base moves with the macula and their tops stand still with the otoliths. This bending sends signals to the nerves and then to the brain, indicating the presence of a sound. Most fishes detect sounds from 30 to 800 or 1000 Hz, with best hearing from 200 to 500 Hz. However, some fishes, called hearing specialists, have evolved special mechanisms to enhance hearing to 3000 or 4000 Hz. The hearing specialists use a secondary structure, the swim bladder, to enhance hearing capabilities. The swim bladder is a bubble of gas found in the abdominal cavity of most bony fishes, and it is used primarily for buoyancy control, though it may also be used in sound production in some species. Since the swim bladder is filled with gas, its density is different from that of the rest of the fish, and in a sound field the walls of the swim bladder are set into vibration and act as a small sound source to send sounds to the ear. See Swim bladder

Tetrapods

Many structural and functional features of the fish inner ear are also found in the tetrapod ear. The inner ear of tetrapods is embedded in the otic bones of the skull, with the membranous labyrinth attached to the bony labyrinth by connective tissue but suspended in perilymphatic fluid. There are three semicircular canals, with cristae, and, except in mammals which do not have a lagena, the three otolithic organs (Fig. 1b, c, d). In their morphology and physiology the vestibular parts of fish and tetrapod ears are nearly the same. For the most part, the tetrapod otolithic organs function only as vestibular organs rather than playing an auditory role as they do in fishes.

Amphibians

The tympanic membrane of frogs and toads is located on the lateral surface of the head. Attached to its inner aspect is a small rodlike bone, the stapes, or columella, which runs through the air space of the middle-ear cavity and plugs a small hole, the oval window, beyond which are the inner-ear fluids. The frog's tympanic membrane collects sound energy and transmits it through the columella to the inner-ear fluids. In the lagenar portion of the amphibian's membranous labyrinth are two areas of hair cells, the amphibian and basilar papillae, that are found in no other vertebrate group. The basilar papilla lies on the posterior wall of the saccule between the oval window and the round window, another membrane-covered opening between middle ear and inner ear. Vibratory energy enters the inner ear at the oval window, passes through the basilar and amphibian papillae causing them to vibrate, and then dissipates at the round window. See Amphibia

Birds and reptiles

In most reptiles and birds the tympanic membrane lies not on the surface of the head but internally, at the end of the tube called the external auditory meatus. A middle-ear cavity (with its eustachian tube to the mouth) lies medial to the tympanic membrane. A single ossicle, the columella, crosses this cavity from the tympanic membrane to the oval window at the inner ear. While both birds and reptiles have saccule, utricle, and lagena, as well as semicircular canals, they also have a newly evolved end organ, the basilar papilla, which is the part of the ear used for hearing in both groups of animals. (The avian and reptilian basilar papilla is thought to be a totally different structure, in terms of evolution and embryonic origin, than the basilar papilla found in amphibians.) The basilar papilla in birds and reptiles is often also called the cochlea, and there is some evidence to suggest that this end organ is directly related to the mammalian cochlea. The basilar papilla in reptiles is generally somewhat shorter than that found in birds, and there is considerable variation in the specific structure of this end organ in different species. The basilar papilla contains sensory hair cells. In birds, the basilar papilla sensory hair cells are differentiated into short and tall hair cells, which may have different functions in hearing. See Aves, Reptilia

Mammals

The mammalian ear consists of three parts: the external ear which receives the sound waves; the middle ear which transmits the vibrations by a series of three small bones; and the inner, or internal, ear, a complex bony chamber placed deep in the skull (Fig. 2). The external auditory meatus plus the newly evolved pinna, a cartilaginous structure projecting from the ear, compose the external ear. The shape and size of the pinna vary greatly. The auditory function of the pinna varies widely in different species. In some species the pinna is moved in the direction of a sound source and helps the animal focus sound to the external auditory meatus and then down the ear canal. In other species, such as humans, the pinna may have a lesser function, but even in humans the pinna helps to discriminate between sounds coming from the front and back of the head so that the person can better tell the direction of a sound source. See Mammalia

Schematic drawing of the human ear

As in other tetrapods, the first gill slit is modified as a middle-ear cavity, communicating with the pharynx by way of the eustachian tube. In other tetrapods this tube is permanently open, while in mammals it is usually closed. Instead of the single columella of other tetrapods, the mammalian middle ear has three bones, closely articulated with one another. The innermost is the stapes, which fits into the oval window of the inner ear and is homologous with the columella. Attached to the tympanic membrane is the malleus, and lying between the malleus and stapes is the incus. In spite of having additional bones, the mammalian middle ear functions basically as do those of amphibians, reptiles, and birds in transforming aerial vibrations into fluid vibrations within the inner ear.

In the mammalian inner ear the vestibular apparatus is much like that of other tetrapods. The auditory portion, however, is elongated and coiled into a snail shape. This structure is called the cochlea. The epithelium of the basilar papilla, called the organ of Corti, is more differentiated in mammals than in other tetrapods. The number of turns in the cochlea varies. At the base of the cochlea is the oval window, which carries sound energy into the inner ear, and the round window, where this energy is dissipated after traveling in the cochlea.

Running the length of the coiled cochlea are three channels; the uppermost, the scala vestibule, and the lowest, the scala tympani, are filled with perilymph. In the center is the scala media, or cochlear duct. The cochlear duct is filled with endolymph, and it is separated from the scala vestibule above by the thin Reissner's membrane and from the scala tympani below by the basilar membrane.

The basilar membrane is suspended on both sides by ligaments or bone. The basilar membrane varies regularly in width, being narrow at the base (where it is most responsive to high frequencies) and wide at the apex (where it is most responsive to low frequencies). Resting upon the basilar membrane is the organ of Corti. The organ of Corti contains several cell types in addition to the auditory hair cells. The hair cells lying on the internal side of the pillar cells are called the inner hair cells, and those lying on the external side are called the outer hair cells. There may be up to 20,000 sensory hair cells in a cochlea of a normal young human, although the number of hair cells declines with age as a result of normal cell death, damage due to some medications, and trauma caused by loud sounds. A healthy teenager may hear sounds from below 20 Hz to upward of 20,000 Hz, while an adult 40 or 50 years old may hear sounds only to 14,000 Hz (or even less). This loss of hearing is associated with death of sensory hair cells.

Sounds entering the mammalian inner ear at the oval window travel along the basilar membrane from basal to apical ends, causing vibrations of the membrane. Different frequencies maximally excite different regions of the basilar membrane based on differences in the stiffness of the membrane itself. The response of the different regions of the organ of Corti to specific frequencies is also thought to be enhanced by the sensory hair cells themselves. Whereas early investigations suggested that both inner and outer hair cells were involved in detection of sound per se, recent evidence suggests that the inner hair cells have the major role in hearing, while the outer hair cells modify the function of the ear and help to enhance the sensitivity of the inner hair cells. See Hearing (human)

Ear

the organ of hearing and balance in vertebrates, including man; the peripheral part of the auditory system. During the course of evolution the ear developed in the anamniote ancestors of vertebrates from specialized sensory skin organs. There is an inner, middle, and external ear.

The inner ear, found in all classes of vertebrates, has a complex membranous labyrinth that is lined with sensory epithelium containing receptor hair cells and otoliths and that is filled with a fluid, the endolymph. The membranous labyrinth lies within a cartilaginous or bony labyrinth. The narrow area between the membranous and bony labyrinths is filled with perilymph; in terrestrial vertebrates this area is connected to the lymph sinuses of the head. The function of the inner ear is to perceive acoustic oscillations as well as changes in the body’s position in space; this is achieved by means of the cochlea and vestibule.

The middle ear occurs only in terrestrial vertebrates. It transmits acoustic oscillations to the inner ear; consequently, the elements of the latter become altered in shape and convert acoustic pressure into nerve impulses. The middle ear consists of an air-filled space, the tympanic cavity, containing the ossicles and the eustachian tube, which is connected to the pharynx. The outer wall of the tympanic cavity turns into a thin, elastic tympanic membrane. The sound waves that reach the membrane are transmitted to the inner ear. In amphibians, reptiles, and birds this occurs by means of an auditory ossicle, the columella, which oscillates in order to transmit sound waves efficiently.

In mammals the sound-conducting system consists of three ossicles. The inner ossicle, or stapes, is adjacent to the oval window of the auditory cavity and corresponds to the columella in amphibians, reptiles, and birds. The outer ossicle, or malleus, is connected to the tympanic membrane, and the middle ossicle, or incus, is joined to the malleus and stapes and fixed to the wall of the auditory cavity. The middle ear of many vertebrates has undergone extensive structural change because of ecological changes and increased specialization in the vertebrates’ way of life. A secondary reduction of the auditory cavity was a common result of the transition to an aquatic mode of life; it is observed, for example, in dolphins. The same change has occurred in burrowing mammals and in some lizards and snakes. The structure of the middle ear and its components is particularly complex in birds and mammals whose hearing is exceptionally sensitive.

The external ear occurs in rudimentary form in reptiles and birds and is well developed in mammals in the form of the pinna. The external ear first appeared in crocodiles because a tympanic membrane was located under the skin and because an external auditory canal with prominences on its periphery developed to form the rudiment of the pinna. In mammals the external ear is generally an elongated auditory canal.

G. N. SIMKIN

The ear is subject to congenital defects, injuries, and diseases. Congenital defects include atresia (imperforation) of the external auditory canal, often combined with an underdeveloped pinna (microtia) or complete absence of the pinna (anotia). Anomalies of the middle ear are generally associated with impaired development of the external and inner ear. Among these anomalies are the presence of bone tissue in the tympanic cavity and the absence of auditory ossicles or their fusion. Congenital defects of the inner ear include absence or underdevelopment of the organ of Corti.

The external ear is the part of the ear most susceptible to injury. Injuries of the pinna, particularly those that occur during sports, often result in a hematoma, or accumulation of blood under the skin or perichondrium of the pinna. The middle and inner ear are generally injured during injuries to the skull. Localized injury to the inner ear results from exposure to very loud sounds, from prolonged exposure to loud noise, and from sudden drops in air pressure.

The most common noninflammatory disease of the external ear is the excessive secretion of ear wax, which sometimes completely obstructs the external auditory canal. Fungus infections are also common in the external auditory canal. Progressive loss of hearing may result from a proliferation of bone tissue in the region of the oval window, which connects the middle and inner ear. Noninflammatory diseases of the inner ear occur in poisonings and in disorders of the circulatory and autonomic nervous systems and of the endocrine glands. Such diseases, called labyrinthopathies, are sometimes manifested by recurrent attacks of dizziness and progressive loss of hearing.

L. V. NEIMAN

REFERENCES

Shmal’gauzen, I. I. Osnovy sravnitel’noi anatomii pozvonochnykh zhivotnykh, 4th ed. Moscow, 1947.
Prosser, C. L., and F. Brown. Sravnitel’naia fiziologiia zhivotnykh. Moscow, 1967. (Translated from English.)
Prives, M. G., N. K. Lysenkov, and V. I. Bushkovich. Anatomiia cheloveka. Leningrad, 1974.
Tsimmerman, G. S. Ukho i mozg, 2nd ed. Moscow, 1974.

What does it mean when you dream about an ear?

Ears naturally symbolize “giving ear” to something, whether it be advice, the promptings of one’s conscience, or divine inspiration. Ears are also often associated with women and sex.

ear

[ir] (anatomy) The receptor organ that sends both auditory information and space orientation information to the brain in vertebrates.

ear

1. Any small projecting member or part of a piece or structure, either decorative or structural. 2.See shoulder, 1. 3. Same as crossette, 1.

ear

¹1. the organ of hearing and balance in higher vertebrates and of balance only in fishes. In man and other mammals it consists of three parts (see external ear, middle ear, internal ear) 2. the outermost cartilaginous part of the ear (pinna) in mammals, esp man 3. by ear without reading from written music 4. play by ear to perform a musical piece on an instrument without written music

ear

² the part of a cereal plant, such as wheat or barley, that contains the seeds, grains, or kernels

EAR

(1) (Enterprise ARchive) A file that contains an entire Java EE application including its components and deployment descriptors. See WAR.

(2) (Export Administration Regulations) Regulations administered by the U.S. Department of Commerce, replacing the ITAR in 1996 as the governing regulations for the export of strong commercial cryptographic products. The EAR relaxed restrictions on such exports. See Wassenaar Arrangement and ITAR.

Ear

(dreams)Your unconscious mind may be suggesting a need to become more attentive to and more aware of internal and external stimuli. In order to learn we must listen to inner and outer voices. Good listening skills are a source of information that enables us to respond more appropriately to the world around us.

ear

[ēr] the organ of hearing and equilibrium. (See Plates.) It is made up of the outer (external) ear, the middle ear, and the inner (internal) ear.
The outer ear consists of the auricle or pinna and the external meatus" >acoustic meatus. The auricle collects sound waves and directs them to the external acoustic meatus; from there the waves travel through the external auditory canal to the eardrum (tympanic membrane).
The middle ear is separated from the outer ear by the eardrum. It contains the three ossicles, the malleus (hammer), incus (anvil), and stapes (stirrup), so called because of their resemblance to these objects. These three small bones form a chain across the middle ear from the eardrum to the oval window. The stapes causes a membrane in the oval window to vibrate, and the vibrations are transmitted to the inner ear. The middle ear is connected to the nasopharynx by the eustachian tube" >eustachian tube, through which the air pressure in the middle ear is equalized with the air pressure in the nose and throat. The middle ear is also connected with the cells in the mastoid bone just behind the outer ear. Two muscles attached to the ossicles contract when loud noises strike the tympanic membrane, limiting its vibration and thus protecting it and the inner ear from damage.
The inner ear (or labyrinth) contains the cochlea, as well as the nerves that transmit sound to the brain. It also contains the semicircular canals, which are essential to the sense of equilibrium" >sense of equilibrium.
When a sound strikes the ear it causes the tympanic membrane to vibrate. The ossicles function as levers, amplifying the motion of the tympanic membrane, and passing the vibrations on to the cochlea. From there the vestibulocochlear (eighth cranial) nerve transmits the vibrations, translated into nerve impulses, to the auditory center in the brain.Diseases of the Ear. Infections and inflammations of the ear include otomycosis, a fungal infection of the outer ear; otitis media, infection of the middle ear; and mastoiditis, an infection of the mastoid cells. deafness may result from infection or from other causes such as old age, injury to the ear, hereditary factors, or conditions such as otosclerosis. Disorders of equilibrium may be caused by imperfect functioning of the semicircular canals or from labyrinthitis" >labyrinthitis, an inflammation of the inner ear. Menière's disease, believed to result from dilatation of the lymphatic channels in the cochlea, may also cause disturbances in balance.Surgery of the Ear. Surgical procedures on the ear usually are indicated for chronic infection or hearing loss. An exception is myringotomy" >myringotomy, incision of the tympanic membrane, which is sometimes necessary to relieve pressure behind the eardrum and allow for drainage from an inflammatory process in the middle ear. Surgical procedures involving plastic reconstruction of the small bones of the middle ear are extremely delicate and have been made possible by the development of special instruments and technical equipment. stapedectomy and tympanoplasty are examples of this type of surgery, which has done much to preserve hearing that would otherwise be lost as a result of infectious destruction or sclerosis. Inner ear implants are now being performed to improve hearing in patients who have severe sensorineural hearing loss. Other surgical techniques for sensorineural hearing loss are in the developmental stage.Patient Care. Care following surgery of the ear is aimed at preventing infection and promoting the comfort of the patient. Since the ear is so close to the brain, it is extremely important to avoid introducing pathogenic organisms into the operative site. The external ear and surrounding skin must be kept scrupulously clean. If the patient's hair is long it should be braided or arranged so that it does not come in contact with the patient's ear and side of the face. Aseptic technique must be used in all procedures carried out immediately before and after surgery.
The patient should be instructed to avoid nose blowing, especially after surgery, when there is a possibility that such an action can alter pressure within the ear. Observation of the patient after surgery of the ear includes assessing function of the facial nerve; evidence of dysfunction could include inability to wrinkle the forehead, close the eyes, pucker the lips, or bare the teeth. Any sign of facial nerve damage should be reported to the surgeon. vertigo" >vertigo is another common occurrence after surgery of the ear; it is usually only temporary and will subside as the operative site heals. The patient with vertigo requires special protective measures such as side rails and support when out of bed, so as to avoid falls or other accidental injuries.
Most surgeons prefer that the dressings around the ear not be changed during the immediate postoperative period. Should excessive drainage require more dressings, these can be applied over the basic dressing. Any drainage should be noted and recorded, with excessive drainage reported immediately to the surgeon. (See also care of the patient with hearing loss" >hearing loss.)

Anatomical features of the external ear. From Ignatavicius and Workman, 2002.

Structures of the middle ear.beach ear otitis externa caused by irritation from ocean water and other beach conditions.cauliflower ear a thickened and deformed ear caused by accumulation of fluid and blood clots in the tissue after repeated injury; it is most often seen in boxers, for whom it is almost an occupational hazard. The ear will not recover its normal shape but can be restored to normal by plastic surgery.swimmer's ear (tank ear) otitis externa.

ear

(ēr), [TA] The organ of hearing and equilibrium, composed of the external ear, consisting of the auricle, external acoustic meatus, and tympanic membrane; the middle ear, or tympanic cavity, with its auditory ossicles and associated muscles; and the internal ear, vestibulocochlear organ, which includes the bony labyrinth (of semicircular canals, vestibule, and cochlea), vestibular and cochlear labyrinths.
See also: auricle. Synonym(s): auris [TA] [A.S. eáre]

ear

(îr)n.1. Anatomy a. The vertebrate organ of hearing, responsible for maintaining equilibrium as well as sensing sound and divided in mammals into the external ear, the middle ear, and the inner ear.b. The part of this organ that is externally visible.2. An invertebrate organ analogous to the mammalian ear.3. The sense of hearing: a sound that grates on the ear.

ear′less adj.

ear

Physical exam The auditory apparatus, which is divided into the external ear–a conical tube that collects sound that vibrates the tympanic membrane–the outer barrier of the middle ear, which contains the ossicles–malleus, incus, and stapes, that mechanically amplify the sound transmitted at the oval window to the cochlea; the cochlea's neuroepithelial hair cells convert the mechanical signal into an electrical/neural signal that is identified by the brain as sounds, speech, music, etc. See Blue ear, Cauliflower ear, Inner ear, Lop ear, Malrotated ear, Middle ear, Mozart ear, Outer ear, Outstanding ear, Satyr ear, Swimmer's ear, Third ear.

EAR

Abbreviation for estimated average requirement.

ear

(ēr) [TA] The organ of hearing: composed of the external ear, which includes the auricle and the external acoustic, or auditory, meatus; the middle ear, or the tympanic cavity with its ossicles; and the internal ear or inner ear, or labyrinth, which includes the semicircular canals, vestibule, and cochlea.
See also: auricle
Synonym(s): auris [TA] .

ear

(er)

STRUCTURE OF THE EARThe organ of hearing and equilibrium. It consists of outer, middle, and inner portions, and is innervated by the eighth cranial nerve. See: illustration

The pathway of hearing is as follows: the auricle funnels sound waves from the environment through the external auditory canal to the tympanic membrane, which makes this thin epithelial structure vibrate. The vibrations are transmitted to the auditory ossicles and then to the perilymph and endolymph. The receptors are part of the organ of Corti and generate impulses transmitted by the cochlear branch of the eighth cranial nerve to the spiral ganglion and auditory tracts of the brain. The auditory areas are in the temporal lobes.

The healthy human ear responds to a variety of sounds, with frequencies ranging from about 20 to 20,000 Hz. It is most sensitive, however, to sounds whose frequencies fall in the 1500- to 3000-Hz range, the frequency range of most human speech. See: hearing

The receptors for equilibrium are in the utricle, saccule, and semicircular ducts, which are innervated by the vestibular branch of the eighth cranial nerve. Impulses from the utricle and saccule provide information about the position of the head, those from the semicircular ducts about the speed and direction of three-dimensional movement.

Blainvilleear

See: Blainville ear

Cagot ear

An ear without a lower lobe.

cauliflower ear

A colloquial term for a thickening of the external ear resulting from trauma. It is commonly seen in boxers. Plastic surgery may restore the ear to a normal shape.

darwinian ear

See: darwinian ear

external ear

The portion of the ear consisting of the auricle and external auditory canal, and separated from the middle ear by the tympanic membrane or eardrum. Synonym: auris externa; outer ear

foreign bodies in ear

Objects that enter the ear accidentally or are inserted deliberately. These are usually insects, pebbles, beans or peas, cotton swabs, or coins.

Symptoms

Foreign objects cause pain, ringing, or buzzing in the ear. A live insect usually causes a noise.

Treatment

Water must not introduced if any vegetable matter is in the ear because the water may push the foreign body further into the ear or cause the matter to swell and become firmly embedded.

To remove insects from the ear, a few drops of lidocaine should be instilled. Inorganic foreign bodies can be removed with small forceps by a health care provider.

glue ear

The chronic accumulation of a viscous exudate in the middle ear, occurring mostly in children between 5 and 8. It causes deafness, which can be treated by removal of the exudate.

STRUCTURE OF THE INNER EAR

inner ear

The portion of the ear consisting of the cochlea, the vestibule, and the bony semicircular canals, which contain the receptors for static and dynamic equilibrium. The receptors are innervated by the vestibulocochlear nerve. Synonym: auris interna; Internal ear See: illustration

internal ear

Inner ear.

lop ear

A cosmetic deformity of the earlobe in which the upper portion of the earlobe bows out laterally from the head.

middle ear

The air-filled expansion of the auditory tube separating the external auditory canal from the inner ear. Sound is transmitted through the middle ear as vibrations along a chain of three tiny bones, the auditory ossicles. Synonym: tympanic cavity See: eardrum; tympanum

Mozart ear

See: Mozart ear

nerve supply of ear

External: The branches of the facial, vagus, and mandibular nerves and the nerves from the cervical plexus. Middle: The tympanic plexus and the branches of the mandibular, vagus, and facial nerves. Internal:The vestibulocochlear nerve (eighth cranial).

outer ear

External ear.

pierced ear

An earlobe that has been pierced with a needle so that a permanent channel will remain, permitting the wearing of an earring attached to the ear by a connector that passes through the channel.

surfer's ear

The formation of an exostosis in the external auditory canal of surfers, esp. those who habitually surf in colder waters.

swimmer's ear

A type of external otitis seen in swimmers, usually during the summer. It is typically caused by Staphylococcus aureus or Pseudomonas aeruginosa and is treated with a suspension of neomycin, polymyxin B sulfate, and hydrocortisone.

Fig. 139 Ear . The human ear.

ear

the sense organ of vertebrates concerned with reception of sound (hearing), BALANCE (detecting position with respect to gravity) and acceleration. The external ear is absent in amphibia and some reptiles, where the eardrum (tympanum) is at the skin surface; in other forms the external ear consists of an AUDITORY CANAL and the pinna, a projection of skin and cartilage. The middle ear or tympanic cavity (not present in some amphibians and some reptiles) lies between the ear drum and the auditory capsule. The EUSTACHIAN TUBE connects the middle ear to the pharynx; it contains the ear ossicles and lies within the bulla which is a projection of the skull. The inner ear or membranous labyrinth is contained in the auditory capsule; the utricle gives rise to the semicircular canals (for balance), and from the saccule the hearing organ arises in the form of the COCHLEA in some tetrapods.

Hearing results from sound waves striking the tympanic membrane and causing it to vibrate. The vibrations are transmitted to the oval window by means of a lever system operating between the three ear ossicles which magnify them. This disturbs the fluid in the vestibular canal of the cochlea and causes movement in REISSNER'S MEMBRANE, which then results in the fluid of the middle canal being displaced. This moves the basilar membrane and then disturbs the fluid in the tympanic canal which stretches the membrane covering the round window. Movement of the basilar membrane stimulates the organ of Corti (see COCHLEA and impulses are fired in the auditory nerve. Loud sounds cause greater movement of the basilar membrane and a higher frequency of impulses from the organ of Corti. Pitch of a sound determines the frequency of movement of the basilar membrane.

EAR

Abbreviation for estimated average requirement.

ear

(ēr) [TA] Organ of hearing and equilibrium, composed of external ear,, consisting of auricle, external acoustic meatus, and tympanic membrane; middle ear,, or tympanic cavity, with its auditory ossicles and associated muscles; and internal ear,, the vestibulocochlear organ, which includes the bony labyrinth (of semicircular canals, vestibule, and cochlea), and vestibular and cochlear labyrinths.
Synonym(s): auris.

Patient discussion about ear

Q. Tinnitus (Ringing and Other Ear Noise) Anybody have this problem?Urrrrrrrrrrr, I think I want to shoot myself,you know what I mean.It is worst than the chinese torture.Someone, please send me a good tip how to stop it.I have this for 4 yrs and it is driving me crazy.You cannot enjoy total complete silence.They say silence is golden but not when you have this ringgi in your ears.It gets worst when there is no noise.The only remedy I have is eating hot spicy curry, it helps for 2-3 wks and then it comes back again and then eating spicy food again.Listening to classical music helps to.Oh well.....just have to suck it up.A. I've read that lipoflavinoids can help.

Q. What causes high pitch ringing in one ear? A. I never knew that about Iron. Thank you F3_4u

Q. my ears do not hear well especially when it's cold. i hear my breath and heart beat. what's my prolem? Denis when i breathe it feels like the breath goes through the ear when the weather is cold or when i do some excercise like joggingA. for ear infections or blocked ear tube - try out the eardoc www.eardoc.info

More discussions about ear

See ear

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ear 1

ear 2

ear

ear

ear1

ear2

ear 1

ear 2

Ear

ear

ear

ear

Parts of the ear

ear

ear1

ear2

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The Hearing Process

Balance and Orientation

Disorders of the Ear

Ear (vertebrate)

Ear structure

Fishes

Tetrapods

Amphibians

Birds and reptiles

Mammals

Ear

REFERENCES

What does it mean when you dream about an ear?

ear

ear

ear

ear

EAR

Ear

ear

ear

ear

ear

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EAR

ear

ear

Blainvilleear

Cagot ear

cauliflower ear

darwinian ear

external ear

foreign bodies in ear

Symptoms

Treatment

glue ear

inner ear

internal ear

lop ear

middle ear

Mozart ear

nerve supply of ear

outer ear

pierced ear

surfer's ear

swimmer's ear

ear

EAR

ear

Patient discussion about ear

EAR

ear

Synonyms for ear

noun sensitivity

Synonyms

noun attention

Synonyms

phrase be out on your ear

Synonyms

ear¹

ear²

ear¹

ear²

ear¹

ear²

ear¹

ear²