vestigial organ


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organ

 [or´gan]
accessory digestive o's (accessory o's of digestive system) organs and structures not part of the alimentary canal that aid in digestion; they include the teeth, salivary glands, liver, gallbladder, and pancreas.
organ of Corti the organ lying against the basilar membrane in the cochlear duct, containing special sensory receptors for hearing, and consisting of neuroepithelial hair cells and several types of supporting cells.
effector organ a muscle or gland that contracts or secretes, respectively, in direct response to nerve impulses.
enamel organ a process of epithelium forming a cap over a dental papilla and developing into the enamel.
end organ end-organ.
Golgi tendon organ any of the mechanoreceptors arranged in series with muscle in the tendons of mammalian muscles, being the receptor for stimuli responsible for the lengthening reaction.
sense o's (sensory o's) organs that receive stimuli that give rise to sensations, i.e., organs that translate certain forms of energy into nerve impulses that are perceived as special sensations.
spiral organ organ of Corti.
target organ the organ affected by a particular hormone.
vestigial organ an undeveloped organ that, in the embryo or in some remote ancestor, was well developed and functional.
o's of Zuckerkandl para-aortic bodies.

ves·tig·i·al or·gan

a rudimentary structure in humans corresponding to a functional structure or organ in the lower animals.

ves·tig·i·al or·gan

(ves-tij'ē-ăl ōr'găn)
A rudimentary structure in humans corresponding to a functional structure or organ in lower animals.

vestigial organ

any organ that during the course of evolution has become reduced in function and usually size. Examples include the pelvic girdle in the whale and wings in flightless birds. Often such organs have lost their original use and are used for other purposes. For example, the penguin's forelimbs are adapted for swimming.

organ

a somewhat independent body part that performs a specific function or functions.

organ of Corti
the organ lying against the basilar membrane in the cochlear duct, containing special sensory receptors for hearing, and consisting of neuroepithelial hair cells and several types of supporting cells.
effector organ
a muscle or gland that contracts or secretes, respectively, in direct response to nerve impulses.
enamel organ
see enamel organ.
female reproductive organ
paired ovaries, uterine tubes, uterus, vagina and vulva.
genital organ
see penis, vulva, etc.
Golgi tendon organ
gustatory organ
taste bud.
gustus organ
see taste bud.
organ of Jacobson
see vomeronasal organ (below).
male reproductive organ
paired testes, gonadal duct systems (epididymis, ductus deferens), accessory glands, urethra, penis, prepuce and scrotum.
ocular organ
see eye.
olfactory organ
the organ of smell in the nasal mucosa consisting of specialized cells with a tuft of very fine processes protruding into the nasal cavity. Internally they communicate with the olfactory nerves which pass through the cribriform plate of the ethmoid bone to synapse with cells in the glomeruli of the olfactory bulb of the brain.
reproductive o's
those concerned with reproduction. See also penis, vulva, etc.
sense o's, sensory o's
organs that receive stimuli that give rise to sensations, i.e. organs that translate certain forms of energy into nerve impulses which are perceived as special sensations.
solid organ
any organ which does not contain a cavity or lumen and which is not gaseous; that is an organ which consists of parenchyma and stroma, the latter often arranged as trabeculae or surrounding groups of parenchymatous cells to provide support, e.g. liver, kidney.
spiral organ
organ of Corti.
spiral organ of the inner ear
the cochlea.
subfornical organ
a small tubercle in the floor of the third ventricle.
target organ
the organ affected by a particular hormone.
tubular organ
an organ characterized by the presence of a lumen and four concentric tunics in its wall; centrifugally the layers are mucosal, submucosal, muscular and adventitia-serosal.
urinary organ's
vascular organ of the lamina terminalis
in the wall of the third ventricle of the brain.
vestibulocochlear organ
the cochlear duct, semicircular canals, utricle and saccule that occupy the osseous labyrinth.
vestigial organ
an undeveloped organ that, in the embryo or in some remote ancestor, was well developed and functional.
vomeronasal organ
part of the olfactory sense system that consists of a pair of fleshy tubes found on the floor of the nasal cavity on either side of the nasal septum, supported by cartilage sleeve. Probably concerned with scenting and aftersmell of food.
References in periodicals archive ?
The notion of performing a relatively minor laparoscopic procedure to remove a vestigial organ to potentially spare poorly controlled ulcerative colitis patients from proctocolectomy is highly attractive.
DISCUSSION: Appendix is considered as vestigial organ but has been a source of surgical emergency from time unknown.
He has published over seventy peer-reviewed articles that focus mainly on dinosaur paleobiology, reptile biology, vestigial organs, and the creation-evolution debate.
Even in ultra-clean societies, then, the appendix and other vestigial organs might be unrecognized heroes.
Washington, July 31 (ANI): Vestigial organs like appendix, spleen, tonsils and various redundant veins, which have long been considered useless, are not really expendable as previously believed, according to researchers.
Well for the purposes of archery, your bow hand and bow arm are vestigial organs, useless implements--merely passive extensions of your body.