| MCA | major coronary artery; Maternity Center Association; medical care administration; methylcholanthrene... |
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| MCAO | middle cerebral artery occlusion |
| MCAS | middle cerebral artery syndrome |
| MCAT | medical college admission test; middle cerebral artery thrombosis |
| MHA | major histocompatibility antigen; May-Hegglin anomaly; Mental Health Association; methemalbumin; mic... |
| isthmus of cartilage of ear | A narrow bridge connecting the cartilage of the external acoustic meatus and the lamina of the tragus with the main portion of the cartilage of the auricle. Synonym: isthmus cartilaginis auris. (05 Mar 2000) |
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| tag, ear | Common minor anomaly, a rudimentary tag of ear tissue, often containing a core cartilage, usually located just in front of the ear (auricle). Therefore, also called preauricular tag. The presence of 2 or more minor anomalies in a child increases the probability that the child has a major malformation. (12 Dec 1998) |
| ear | 1. The organ of hearing; the external ear. In man and the higher vertebrates, the organ of hearing is very complicated, and is divisible into three parts: the external ear, which includes the pinna or auricle and meatus or external opening; the middle ear, drum, or tympanum; and the internal ear, or labyrinth. The middle ear is a cavity connected by the Eustachian tube with the pharynx, separated from the opening of the external ear by the tympanic membrane, and containing a chain of three small bones, or ossicles, named malleus, incus, and stapes, which connect this membrane with the internal ear. The essential part of the internal ear where the fibres of the auditory nerve terminate, is the membranous labyrinth, a complicated system of sacs and tubes filled with a fluid (the endolymph), and lodged in a cavity, called the bony labyrinth, in the periotic bone. The membranous labyrinth does not completely fill the bony labyrinth, but is partially suspended in it in a fluid (the perilymph). The bony labyrinth consists of a central cavity, the vestibule, into which three semicircular canals and the canal of the cochlea (spirally coiled in mammals) open. The vestibular portion of the membranous labyrinth consists of two sacs, the utriculus and sacculus, connected by a narrow tube, into the former of which three membranous semicircular canals open, while the latter is connected with a membranous tube in the cochlea containing the organ of Corti. By the help of the external ear the sonorous vibrations of the air are concentrated upon the tympanic membrane and set it vibrating, the chain of bones in the middle ear transmits these vibrations to the internal ear, where they cause certain delicate structures in the organ of Corti, and other parts of the membranous labyrinth, to stimulate the fibres of the auditory nerve to transmit sonorous impulses to the brain. 2. The sense of hearing; the perception of sounds; the power of discriminating between different tones; as, a nice ear for music; in the singular only. "Songs . . . Not all ungrateful to thine ear." (Tennyson) 3. That which resembles in shape or position the ear of an animal; any prominence or projection on an object, usually one for support or attachment; a lug; a handle; as, the ears of a tub, a skillet, or dish. The ears of a boat are outside kneepieces near the bow. 4. Same as Acroterium . Same as Crossette. 5. Privilege of being kindly heard; favor; attention. "Dionysius . . . Would give no ear to his suit." (Bacon) "Friends, Romans, countrymen, lend me your ears." (Shak) About the ears, in close proximity to; near at hand. By the ears, in close contest; as, to set by the ears; to fall together by the ears; to be by the ears. Button ear (in dogs), an ear which falls forward and completely hides the inside. Ear finger, the little finger. Ear of Dionysius, a kind of ear trumpet with a flexible tube; named from the Sicilian tyrant, who constructed a device to overhear the prisoners in his dungeons. <anatomy> Ear sand, a simple auditory organ, occurring in many worms, mollusks, etc. It consists of a small sac containing a fluid and one or more solid concretions or otocysts. Rose ear (in dogs), an ear which folds backward and shows part of the inside. To give ear to, to listen to; to heed, as advice or one advising. "Give ear unto my song." . To have one's ear, to be listened to with favor. Up to the ears, deeply submerged; almost overwhelmed; as, to be in trouble up to one's ears. Origin: AS. Eare; akin to OFries. Are, ar, OS. Ra, D. Oor, OHG. Ra, G. Ohr, Icel. Eyra, Sw. Ora, Dan. Ore, Goth. Auso, L. Auris, Lith. Ausis, Russ. Ukho, Gr.; cf. L. Audire to hear, Gr, Skr. Av to favor, protect. Cf. Auricle, Orillon. Source: Websters Dictionary (01 Mar 1998) |
| ear bones | The small bones of the middle ear; they are articulated to form a chain for the transmission of sound from the tympanic membrane to the oval window. Synonym: ossicula auditus, ear bones, ossicular chain. (05 Mar 2000) |
| ear canal, self-cleaning | most of the time the ear canals are self-cleaning, that is, there is a slow and orderly migration of ear canal skin from the eardrum to the outer opening. Old earwax is constantly being transported from the deeper areas of the ear canal to the opening where it usually dries, flakes, and falls out. (12 Dec 1998) |
| ear cartilages | Cartilages of the auricle (pinna) and the external acoustic meatus. (12 Dec 1998) |
| ear cleaning | When so much wax accumulates that it blocks the ear canal (and hearing), your physician may have to wash it out, vacuum it, or remove it with special instruments. Alternatively, your physician may prescribe ear drops what are designed to soften the wax (such as Cerumenex). Never put anything smaller than your elbow in your ear! Wax is not formed in the deep part of the ear canal near the eardrum, but only in the outer part of the canal. So when a patient has wax pushed up against the eardrum, it is often because he has been probing his ear with such things as cotton-tipped swabs (such as Q-Tips), bobby pins, or twisted napkin corners. Such objects only serve as ramrods to push the wax in deeper. Also, the skin of the ear canal and the eardrum is very thin, fragile and easily injured. The ear canal is more prone to infection after it has been whipped clean of the good coating type wax. In addition, we have seen many perforated eardrums as a result of these efforts. (12 Dec 1998) |
| ear crystals | Crystalline particles of calcium carbonate and a protein adhering to the gelatinous membrane of the maculae of the utricle and saccule. Synonym: statoconia, ear crystals, otoconia, otoliths, otolites, sagitta. Origin: G. Statos, standing, + lithos, stone (05 Mar 2000) |
| ear cyst | A sebaceous cyst that occurs most commonly in the ear canal. They are bulging sac-like collections of dead skin cells and fluid. These cysts can be quite painful and may block the canal causing hearing loss. Treatment may include warm wet compresses, antibiotics (if infected) and surgical removal in some cases. Most resolve spontaneously. (27 Sep 1997) |
| ear deformities, acquired | Distortion or disfigurement of the ear caused by disease or injury after birth. (12 Dec 1998) |
| ear diseases | Diseases of the ear, general or unspecified. (12 Dec 1998) |
| ear lobe | The lowest part of the auricle; it consists of fat and fibrous tissue not reinforced by the auricular cartilage. Synonym: lobulus auriculae, lobule of auricle. (05 Mar 2000) |
| ear lobe crease | A diagonal crease found on one or both earlobes with a possible connection to coronary heart disease in males. (05 Mar 2000) |
| ear, low-set | A minor anomaly involving an ear situated down below its normal location. Technically, the ear is low-set when the helix (of the ear) meets the cranium at a level below that of a horizontal plane through both inner canthi (the inside corners of the eyes). The presence of 2 or more minor anomalies in a child increases the probability that the child has a major malformation. (12 Dec 1998) |
| ear, malrotated | See Ear, slanted. (12 Dec 1998) |