| organ | 1. An instrument or medium by which some important action is performed, or an important end accomplished; as, legislatures, courts, armies, taxgatherers, etc, are organs of government. 2. <biology> A natural part or structure in an animal or a plant, capable of performing some special action (termed its function), which is essential to the life or well-being of the whole; as, the heart, lungs, etc, are organs of animals; the root, stem, foliage, etc, are organs of plants. In animals the organs are generally made up of several tissues, one of which usually predominates, and determines the principal function of the organ. Groups of organs constitute a system. See System. 3. A component part performing an essential office in the working of any complex machine; as, the cylinder, valves, crank, etc, are organs of the steam engine. 4. A medium of communication between one person or body and another; as, the secretary of state is the organ of communication between the government and a foreign power; a newspaper is the organ of its editor, or of a party, sect, etc. 5. [Cf. AS. Organ, fr. L. Organum. A wind instrument containing numerous pipes of various dimensions and kinds, which are filled with wind from a bellows, and played upon by means of keys similar to those of a piano, and sometimes by foot keys or pedals; formerly used in the plural, each pipe being considired an organ. "The deep, majestic, solemn organs blow." (Pope) Chaucer used the form orgon as a plural. "The merry orgon . . . That in the church goon [go]" Barrel organ, Choir organ, Great organ, etc. See Barrel, Choir, etc. <anatomy> Cabinet organ, a passage in which the tonic or dominant is sustained continuously by one part, while the other parts move. Origin: L. Organum, Gr.; akin to work, and E. Work: cf. F. Organe. See Work, and cf. Orgue, Orgy. Source: Websters Dictionary (01 Mar 1998) |
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| organ culture | <cell biology> Culture in vitro of pieces of tissue (as opposed to single cells) in such a way as to maintain some normal spatial relationships between cells and some normal function. Contrast with tissue culture. (18 Nov 1997) |
| organ of corti | The organ that contains the special sensory receptors for hearing. It is composed of a series of epithelial structures placed upon the inner part of the basilar membrane. (12 Dec 1998) |
| organ of hearing | The content of the cochlea including the portion of the membranous labyrinth containing the spiral organ (cochlear duct) and the perilymphatic channels (scalae) which lie on either side. Synonym: labyrinthus cochlearis, organ of hearing. (05 Mar 2000) |
| organ of Rosenmuller | <anatomy> See Parovarium. Origin: NL, from Gr. Upon + egg + to bear. Source: Websters Dictionary (01 Mar 1998) |
| organ of smell | The olfactory region in the superior portion of the nasal cavity. Synonym: organum olfactus, organ of smell. (05 Mar 2000) |
| organ of taste | Located in the papillae of the mucous membrane of the tongue, chiefly in the vallate papillae. Synonym: organum gustus, organ of taste. (05 Mar 2000) |
| organ of touch | Any one of the sensory end organs. Synonym: organum tactus, tactile organ. (05 Mar 2000) |
| organ of vision | The eye and its adnexa. Synonym: organum visus, organ of vision. (05 Mar 2000) |
| organ of zuckerkandl | <radiology> Para-aortic chromaffin body, adjacent to abdominal sympathetic plexus, site: aortic bifurcation or IMA origin, most common extra-adrenal site of pheochromocytoma (12 Dec 1998) |
| organ preservation solutions | Solutions used to store organs, particulary those awaiting implantation. (12 Dec 1998) |
| organ procurement | The obtaining of organs for transplantation, which includes methods of obtaining through programs, systems, or organizations. It includes also the transporting of donor organs, after surgical removal, to the hospital for processing and transplant. (12 Dec 1998) |
| organ specificity | Restriction of a characteristic or response to a particular organ of the body; it usually refers to that property of the immune response which differentiates one organ from another on the basis of antigen recognition, but the concept is not limited to immunology. (12 Dec 1998) |
| organ transplantation | Transference of an organ between individuals of the same species or between individuals of different species. (12 Dec 1998) |
| organ-specific | Denoting or pertaining to a serum produced by the injection of the cells of a certain organ or tissue that, when injected into another animal, destroys the cells of the corresponding organ. (05 Mar 2000) |
| annulospiral organ | One of two types of sensory nerve ending associated with a neuromuscular spindle (the other being the flower-spray ending); after entering the muscle spindle, the fibre divides into two flat ribbon-like branches that wind themselves in rings or spirals about the intrafusal muscle fibres. Synonym: annulospiral organ. (05 Mar 2000) |
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| auditory organ | Archaic term for gustatory organ. (05 Mar 2000) |
| bojanus organ | <zoology> A glandular organ of bivalve mollusca, serving in part as a kidney. Origin: From Bojanus, the discoverer. Source: Websters Dictionary (01 Mar 1998) |
| vestibular organ | Collective term for the utricle, saccule, and saemicircular ducts of the membranous labyrinth, each having a single patch of ciliated receptor epithelium innervated by the vestibular nerve: macula of sacculus, macula of utriculus, and cristae of the saemicircular ducts. (05 Mar 2000) |
| vestibulocochlear organ | The external, middle, and internal ear. Synonym: organum vestibulocochleare. (05 Mar 2000) |
| vestigial organ | A rudimentary structure in humans corresponding to a functional structure or organ in the lower animals. (05 Mar 2000) |
| visual organ | The eye and its adnexa. Synonym: organum visus, organ of vision. (05 Mar 2000) |
| vomeronasal organ | A specialised part of the olfactory system located anteriorly in the nasal cavity within the nasal septum. Chemosensitive cells of the vomeronasal organ project via the vomeronasal nerve to the accessory olfactory bulb. The primary function of this organ appears to be in sensing pheromones which regulate reproductive and other social behaviours. While the structure has been thought absent in higher primate adults, data now suggests it may be present in adult humans. (12 Dec 1998) |
| Golgi tendon organ | <cell biology, physiology> A proprioceptive sensory nerve ending embedded among the fibres of a tendon, often near the musculotendinous junction; it is compressed and activated by any increase of the tendon's tension, caused either by active contraction or passive stretch of the corresponding muscle. Synonym: neurotendinous organ, neurotendinous spindle. (05 Mar 2000) |
| Chievitz' organ | A normal epithelial structure, possibly a neurotransmitter, found at the angle of the mandible with branches of the buccal nerve. (05 Mar 2000) |
| gustatory organ | Located in the papillae of the mucous membrane of the tongue, chiefly in the vallate papillae. Synonym: organum gustus, organ of taste. (05 Mar 2000) |
| rosenmuller's organ | <anatomy> The parovarium. Origin: So named from its first describer, J. C. Rosenmuller, a German anatomist. Source: Websters Dictionary (01 Mar 1998) |
| wandering organ | An organ with loose attachments, permitting its displacement. Synonym: floating organ, ptotic organ. (05 Mar 2000) |
| Weber's organ | A minute pouch in the prostate opening on the summit of the seminal colliculus, the analogue of the uterus and vagina in the female, being the remains of the fused caudal ends of the paramesonephric ducts. Synonym: utriculus prostaticus, masculine uterus, Morgagni's sinus, sinus pocularis, uterus masculinus, vagina masculina, vesica prostatica, Weber's organ. (05 Mar 2000) |
| multiple organ failure | A progressive condition usually characterised by combined failure of the lungs, liver, kidney, and clotting mechanisms, usually postinjury or postoperative. (12 Dec 1998) |