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Medical Dictionary - Dictionary of Medicine and Human Biology


Medical Dictionary


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condenser (kon-den′ser)
1. An apparatus for cooling a gas to a liquid, or a liquid to a solid. 2. In dentistry, a manual or powered instrument used for packing a plastic or unset material into a cavity of a tooth; variation in sizes and shapes allows conformation of the mass to the cavity outline. 3. The simple or compound lens on a microscope that is used to supply the illumination necessary for visibility of the specimen under observation. 4. SYN: capacitor. Abbé c. a system of two or three wide-angle, achromatic, convex and planoconvex lenses that may be moved upward or downward beneath the stage of a microscope, thereby regulating the concentration of light (directly from a bulb or reflected from a mirror) that passes through the material to be examined on the stage. automatic c. SYN: automatic plugger. cardioid c. a type of dark-field c.. dark-field c. an apparatus for throwing reflected light through the microscope field, so that only the object to be examined is illuminated, the field itself being dark. paraboloid c. a type of dark-field c..

condition (kon-dish′un)
1. To train; to undergo conditioning. 2. A certain response elicited by a specifiable stimulus or emitted in the presence of certain stimuli with reward of the response during prior occurrence. 3. Referring to several classes of learning in the behavioristic branch of psychology. [L. conditio, fr. condico, to agree] fibrocystic c. of the breast a benign disease common in women of the third, fourth, and fifth decades characterized by formation, in one or both breasts, of small cysts containing fluid which may appear as blue dome cysts; associated with stromal fibrosis and with variable degrees of intraductal epithelial hyperplasia and sclerosing adenosis. SYN: cystic hyperplasia of the breast.

conditioning (kon-dish′un-ing)
The process of acquiring, developing, educating, establishing, learning, or training new responses in an individual. Used to describe both respondent and operant behavior; in both usages, refers to a change in the frequency or form of behavior as a result of the influence of the environment. assertive c. SYN: assertive training. aversive c. SYN: aversive training. avoidance c. the technique whereby an organism learns to avoid unpleasant or punishing stimuli by learning the appropriate anticipatory response to protect it from further such stimuli. Cf.:escape c.. SYN: avoidance training. classical c. a form of learning, as in Pavlov experiments, in which a previously neutral stimulus becomes a conditioned stimulus when presented together with an unconditioned stimulus. Also called stimulus substitution because the new stimulus evokes the response in question. SEE ALSO: respondent c.. SYN: stimulus substitution. escape c. the technique whereby an organism learns to terminate unpleasant or punishing stimuli by making the appropriate new response which stops the delivery of such stimuli. Cf.:avoidance c.. SYN: escape training. higher order c. the use of a previously conditioned stimulus to condition further responses, in much the same way unconditioned stimuli are used. instrumental c. c. in which the response is a prerequisite to achieving some goal; often used as a synonym for operant c., but some psychologists make distinctions in the usages of these two terms. operant c. a type of c. developed by Skinner in which an experimenter waits for the target response (head scratching) to be conditioned to occur (emitted) spontaneously, immediately after which the organism is given a reinforcer reward; after this procedure is repeated many times, the frequency of emission of the targeted response will have significantly increased over its pre-experiment base rate. SEE ALSO: schedules of reinforcement, under schedule. SYN: skinnerian c.. pavlovian c. SYN: respondent c.. respondent c. a type of c., first studied by I. P. Pavlov, in which a previously neutral stimulus (bell sound) elicits a response (salivation) as a result of pairing it (associating it contiguously in time) a number of times with an unconditioned or natural stimulus for that response (food shown to a hungry dog). SYN: pavlovian c.. second-order c. the use of a previously successfully conditioned stimulus as the unconditioned stimulus for further c.. skinnerian c. SYN: operant c.. trace c. c. when there is no temporal overlap between the c. stimulus and the unconditioned stimulus.

condom (kon′dom)
Sheath or cover for the penis or vagina for use in the prevention of conception or infection during coitus.

conductance (kon-duk′tans)
1. A measure of conductivity; the ratio of the current flowing through a conductor to the difference in potential between the ends of the conductor; the c. of a circuit is the reciprocal of its resistance. 2. The ease with which a fluid or gas enters and flows through a conduit, air passage, or respiratory tract; the flow per unit pressure difference.

conduction (kon-duk′shun)
1. The act of transmitting or conveying certain forms of energy, such as heat, sound, or electricity, from one point to another, without evident movement in the conducting body. 2. The transmission of stimuli of various sorts by living protoplasm. [L. con- duco, pp. ductus, to lead, conduct] aberrant ventricular c. abnormal intraventricular c. of a supraventricular beat, especially where surrounding beats are normally conducted. SYN: ventricular aberration. accelerated c. any pathologically increased speed of c.; usually occurs between the atrium and ventricles as in the Wolff-Parkinson-White and Lown-Ganong-Levine syndromes; such accelerated pathways provide the bases for particular forms of reentry tachycardia. air c. in relation to hearing, the transmission of sound to the inner ear through the external auditory canal and the structures of the middle ear. anomalous c. c. of cardiac electrical impulses through any abnormal pathway. antegrade c. SYN: anterograde c.. anterograde c. c. in the expected normal direction between any cardiac structures. SYN: antegrade c., forward c., orthograde c.. atrioventricular c. (AVC) , AV c. forward c. of the cardiac impulse from atria to ventricles via the AV node or any bypass tract, represented in the electrocardiogram by the PR interval. PH c. time is from the onset of the P wave to the first high-frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H c. time is from the onset of the first high-frequency component of the atrial electrogram to the first high-frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A c. time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). avalanche c. the discharge of an impulse from a neuron into a large number of neurons of the same physiologic system, thus producing the liberation of a very large amount of nervous energy by a given stimulus. bone c. in relation to hearing, the transmission of sound to the inner ear through vibrations applied to the bones of the skull. SYN: osteophony. concealed c. c. of an impulse through a part of the heart without direct evidence of its presence in the electrocardiogram; c. is inferred only because of its influence on the subsequent cardiac cycle. decremental c. impaired c. in a portion of a fiber because of progressively lessening response of the unexcited portion of the fiber to the action potential coming toward it; it is manifested by decreasing speed of c., amplitude of action potential, and extent of spread of the impulse. delayed c. first-degree AV block. See atrioventricular block, intraventricular block, bundle-branch block. forward c. SYN: anterograde c.. intraatrial c. c. of the cardiac impulse through the atrial myocardium, represented by the P wave in the electrocardiogram. intraventricular c. c. of the cardiac impulse through the ventricular myocardium, represented by the QRS complex in the electrocardiogram. HR c. time is from the onset of the first high frequency component of the His bundle electrogram to the onset of the QRS complex of the surface electrocardiogram (normally 43 ± 12 msec); HV c. time is from the onset of the first high-frequency component of the His bundle electrogram to the onset of the ventricular electrogram (normally approximates the HR interval but may be a little shorter). SYN: ventricular c.. nerve c. the transmission of an impulse along a nerve fiber. orthograde c. SYN: anterograde c.. Purkinje c. c. of the cardiac impulse through the Purkinje system. retrograde VA c. c. backward from the ventricles or from the AV node into and through the atria. SYN: retroconduction, ventriculoatrial c., VA c.. saltatory c. c. in which the nerve impulse jumps from one node of Ranvier to the next. sinoventricular c. a rare form of c. of the sinus impulse during paralysis of the atrial muscle by hyperkalemia. The impulse leaves the sinus node and enters the internodal tracts rapidly achieving the junctional tissues but without inscribing a P wave due to the inactivation of the atrial muscle cells. supernormal c. SYN: supranormal c.. supranormal c. transmission of an impulse during the brief period of the cardiac cycle when it would be expected to fail if it occurred outside this time interval; considered to be better than expected rather than better than normal. Cf.:supranormal excitability. SYN: supernormal c.. synaptic c. the c. of a nerve impulse across a synapse. ventricular c. SYN: intraventricular c.. ventriculoatrial c. (VAC) , VA c. SYN: retrograde VA c..

conductivity (kon-duk-tiv′i-te)
1. The power of transmission or conveyance of certain forms of energy, as heat, sound, and electricity, without perceptible motion in the conducting body. 2. The property, inherent in living protoplasm, of transmitting a state of excitation; e.g., in muscle or nerve. hydraulic c. ease of pressure filtration of a liquid through a membrane; specifically, Kf = η(Q/A) (δx/δP), where Kf = hydraulic c., η = viscosity of the liquid being filtered, Q/A = volume of liquid filtered per unit time and unit area, and δx/δP = reciprocal of the pressure gradient through the membrane; solute concentrations should be identical on both sides of the membrane. Also applied more loosely to measurements on a total membrane of unknown area and thickness with unmeasured fluid viscosity (K = Q/δP).

conductor (kon-duk′ter, -tor)
1. A probe or sound with a groove along which a knife is passed in slitting open a sinus or fistula; a grooved director. 2. Any substance possessing conductivity.

conduit (kon′doo-it)
A channel. apical-aortic c. a valved c. between the LV apex and aorta, used to treat severe otherwise unapproachable LV outflow tract obstruction. ileal c. an isolated segment of ileum serving as a cutaneous replacement for the urinary bladder, into which ureters can be implanted, the lumen of which is connected to the skin; used following total cystectomy or other loss of normal bladder function requiring supravesical diversion. SYN: ileal bladder.

conduplicate (kon-doo′pli-kat)
Folded upon itself lengthwise. [L. con-, with, + duplico, pp. -atus]

conduplicato corpore (kon-doo-pli-ka′to kor′por-e)
Condition in which the fetus is doubled up on itself in shoulder presentation.

condurango (kon-doo-rang′go)
The bark of Gonolobus c., Marsdenia c. (family Asclepiadaceae), a shrub of Ecuador and Peru; an aromatic bitter and astringent. [Peruv.]

condylar (kon′di-lar)
Relating to a condyle.

condylarthrosis (kon′di-lar-thro′sis)
A joint, like that of the knee, formed by condylar surfaces. [G. kondylos, condyle, + arthrosis, a jointing]

condyle (kon′dil) [TA]
A rounded articular surface at the extremity of a bone. SYN: condylus [TA] . balancing side c. in dentistry, the mandibular c. on the side away from which the mandible moves in a lateral excursion. c. of humerus [TA] the distal end of the humerus, including the trochlea, capitulum and the olecranon, coronoid and radial fossae. SYN: condylus humeri [TA] . lateral c. [TA] c. farthest from the midline. SYN: condylus lateralis [TA] . lateral c. of femur [TA] the lateral c. is longer than the medial c.. SYN: condylus lateralis femoris [TA] . lateral c. of tibia [TA] the lateral c. is longer than the medial c.. SYN: condylus lateralis tibiae [TA] . mandibular c. SYN: condylar process of mandible. medial c. [TA] c. closest to midline. SYN: condylus medialis [TA] . medial c. of femur [TA] the shorter c. closest to the midline. SYN: condylus medialis femoris [TA] . medial c. of tibia [TA] the shorter c. closest to the midline. SYN: condylus medialis tibiae [TA] . occipital c. [TA] one of two elongated oval facets on the undersurface of the occipital bone, one on each side of the foramen magnum, which articulate with the atlas. SYN: condylus occipitalis [TA] . working side c. in dentistry, the mandibular c. on the side toward which the mandible moves in a lateral excursion.

condylectomy (kon-di-lek′to-me)
Excision of a condyle. [G. kondylos, condyle, + ektome, excision]

condylion (kon-dil′e-on)
A point on the lateral outer or medial inner surface of the condyle of the mandible. [G. kondylion, dim. of kondylos, condyle]

condyloid (kon′di-loyd)
Relating to or resembling a condyle. [G. kondylodes, like a knuckle, fr. kondylos, condyle, + eidos, resemblance]

condyloma, pl .condylomata (kon-di-lo′ma, -mah′ta)
A wartlike excrescence at the anus or vulva, or on the glans penis. [G. kondyloma, a knob] c. acuminatum a contagious projecting warty growth on the external genitals or at the anus, consisting of fibrous overgrowths covered by thickened epithelium showing koilocytosis, due to sexual contact with infection by human papilloma virus; it is usually benign, although malignant change has been reported, associated with particular types of the virus. SYN: genital wart, venereal wart. flat c. 1. SYN: c. latum. 2. a c. of the uterine cervix or other site caused by human papilloma virus infection and characterized histologically by koilocytosis without papillomatosis. giant c. a large type of c. acuminatum found in the anus, vulva, or preputial sac of the penis of middle-aged, uncircumcised men; it tends to extend deeply and recur. SEE ALSO: verrucous carcinoma. c. latum a secondary syphilitic eruption of flat-topped papules, occurring in groups covered by a necrotic layer of epithelial detritus, and secreting a seropurulent fluid; they are found at the anus and wherever contiguous folds of skin produce heat and moisture. SYN: flat c. (1) , moist papule, mucous papule.

condylomatous (kon-di-lo′ma-tus)
Relating to a condyloma.

condylotomy (kon-di-lot′o-me)
Division, without removal of a condyle. [G. kondylos, condyle, + tome, incision]

condylus (kon′di-lus) [TA]
SYN: condyle. [L. fr. G. kondylos, knuckle, the knuckle of any joint] c. humeri [TA] SYN: condyle of humerus. c. lateralis [TA] SYN: lateral condyle. c. lateralis femoris [TA] SYN: lateral condyle of femur. c. lateralis tibiae [TA] SYN: lateral condyle of tibia. c. medialis [TA] SYN: medial condyle. c. medialis femoris [TA] SYN: medial condyle of femur. c. medialis tibiae [TA] SYN: medial condyle of tibia. c. occipitalis [TA] SYN: occipital condyle.

cone (kon)
1. A surface joining a circle to a point above the plane (containing the circle). 2. The photosensitive, outward-directed, conical process of a c. cell essential for sharp vision and color vision; cones are the only photoreceptor in the fovea centralis and become interspersed with increasing numbers of rods toward the periphery of the retina. SYN: c. cell of retina. 3. Metallic cylinder or truncated c., either circular or square in cross-section, used to confine a beam of x-rays. SYN: conus (1) . [G. konos, c.] antipodal c. the set of astral rays of a dividing cell extending from the centriole in a direction opposite to the equatorial plate. arterial c. SYN: conus arteriosus. c. down to confine a beam of x-rays to a region of interest using a collimator or c. (3); colloq., to focus one's attention or activities. elastic c. SYN: conus elasticus. gutta-percha c. a c.-shaped, semirigid root canal filling material composed of gutta-percha and zinc oxide. Haller cones SYN: lobules of epididymis, under lobule. implantation c. SYN: axon hillock. c. of light SYN: light reflex (3) . medullary c. [TA] SYN: conus medullaris. nerve growth c. a highly motile structure at the leading edge of an elongating axon. ocular c. the c. of light in the interior of the eyeball with the base formed by the rays entering through the pupil and the apex focused on the retina. Politzer luminous c. SYN: light reflex (3) . pulmonary c. SYN: conus arteriosus. retinal cones c. (2) . silver c. pure silver c. with standard conical shape, used with cement to obturate dental root canals. theca interna c. the conical thickening of thecal cells of an ovarian follicle with its apex pointed toward the surface. twin c. two retinal cones fused together. vascular cones SYN: lobules of epididymis, under lobule.

-cone
The cusp of a tooth in the upper jaw.

conessi (ko-nes′e)
The bark of Holarrhena antidysenterica (family Apocynaceae), an Indian tree; used as an astringent and in the treatment of dysentery and amebiasis. SYN: kurchi bark. [E. Ind.]

conessine (kon′e-sen)
A steroid alkaloid derived from Holarrhena antidysenterica (conessi); a yellow astringent, used in the treatment of amebic dysentery and vaginal trichomoniasis. SYN: neriine, wrightine.

conexus, pl .conexus (ko-nek′sus)
SYN: connection. [L.] c. intertendineus SYN: intertendinous connections of extensor digitorum, under connection.

confabulation (kon′fab-u-la′shun)
The making of bizarre and incorrect responses, and a readiness to give a fluent but tangential answer, with no regard whatever to facts, to any question put; seen in amnesia and Wernicke-Korsakoff syndrome. [L. con-fabulor, pp. -fabulatus, to talk together, fr. fabula, narrative]

confectio, gen. confectionis, pl .confectiones (kon-fek′she-o, -o′nis, -o′nez)
SYN: confection. [L. fr. conficio, pp. -fectus, to make ready, prepare]

confection (kon-fek′shun)
A pharmaceutical preparation consisting of a drug mixed with honey or syrup; a soft solid, sometimes used as an excipient for pill masses. SYN: confectio, conserve, electuary. [L. confectio]

confertus (kon-fer′tus)
Arranged closely together; coalescing. [L. confercio, pp. -fertus, to cram together, fr. farcio, to fill full, cram]

confidentiality (kon′fi-den-she-al′i-te)
The statutorily protected right afforded to (and duty required of) specifically designated health professionals not to disclose information discerned during consultation with a patient. [L. con-fido, to trust, be assured]

configuration (kon-fig-u-ra′shun)
1. The general form of a body and its parts. 2. In chemistry, the spatial arrangement of atoms in a molecule. The c. of a compound ( e.g., a sugar) is the unique spatial arrangement of its atoms such that no other arrangement of these atoms is superimposable thereon with complete correspondence, regardless of changes in conformation (i.e., twisting or rotation about single bonds); change of c. requires breaking and rejoining of bonds, as in going from d to l configurations of sugars. Cf.:conformation. cis c. 1. See cis- (4) . 2. the property of two or more sites on the same molecule of DNA.

confinement (kon-fin′ment)
Lying-in; giving birth to a child. [L. confine (ntr.), a boundary, confine, fr. con- + finis, boundary]

conflict (kon′flikt)
Tension or stress experienced by an organism when satisfaction of a need, drive, motive, or wish is thwarted by the presence of other attractive or unattractive needs, drives, or motives. approach-approach c. a situation of indecision and vacillation when an individual is confronted with two equally attractive alternatives. approach-avoidance c. a situation of indecision and vacillation when the individual is confronted with a single object or event which has both attractive and unattractive qualities. avoidance-avoidance c. a situation of indecision and vacillation when the individual is confronted with two equally unattractive alternatives. c. of interest a c. between the professional or personal interests and needs of a health provider and his or her professional responsibilities toward a patient or other consumer. interpersonal c. relating to a c. in the relations and social exchanges between persons. Cf.:intrapersonal c.. intrapersonal c. a c. that occurs solely in the psychological dynamics of the individual's own mind. See intrapsychic. role c. the dilemma an individual experiences when required to play two different parts ( e.g., spouse and aggressive business competitor) that cannot be easily harmonized.

confluence (kon′floo-ens) [TA]
A flowing together; a joining of two or more streams. SYN: confluens [TA] . [L. confluens] c. of sinuses [TA] a meeting place, at the internal occipital protuberance, of the superior sagittal, straight, occipital, drained by the two transverse sinuses of the dura mater. SYN: confluens sinuum [TA] .

confluens (kon-floo′enz) [TA]
SYN: confluence, confluence. [L.] c. sinuum [TA] SYN: confluence of sinuses.

confluent (kon′floo-ent)
1. Joining; running together; denoting certain skin lesions which become merged, forming a patch; denoting a disease characterized by lesions which are not discrete, or distinct one from the other. 2. Denoting a bone formed by the blending together of two originally distinct bones. [L. con-fluo, to flow together]

confocal (kon-fo′kal)
See c. microscope.

conformation (kon-for-ma′shun)
The spatial arrangement of a molecule achieved by rotation of groups about single covalent bonds, without breaking any covalent bonds; the latter restriction differentiates c. from configuration (as in anomers and related stereoisomers) where a bond or bonds must be broken in going from one form (configuration) to another. C. is one of the most important aspects of sugar chemistry and is basic to an understanding of the chemical properties of sugars. Cf.:configuration. boat c. Haworth conformational formulas of cyclic sugars. envelope c. Haworth conformational formulas of cyclic sugars.

conformer (kon-for′mer)
A mold, usually of plastic material, used in surgical repair to maintain space in a cavity or to prevent closing by healing of an artificial or natural opening. [L. conformo, to fashion]

confounding
1. A situation in which the effects of two or more processes are not separated; the distortion of the apparent effect of an exposure on risk, brought about by the association with other factors that can influence the outcome. 2. A relationship between the effects of two or more causal factors observed in a set of data, such that it is not logically possible to separate the contribution of any single causal factor to the observed effects.

confrontation (kon-fron-ta′shun)
The act by the therapist, or another patient in a therapy group, of openly interpreting a patient's resistances, attitudes, feelings, or effects upon either the therapist, the group, or its member(s).

confusion (kon-fu′zhun)
A mental state in which reactions to environmental stimuli are inappropriate because the person is bewildered, perplexed, or unable to orientate himself. [L. confusio, a confounding]

confusional (kon-fu′zhun-al)
Characterized by, or pertaining to, confusion.

congener (kon′je-ner)
1. One of two or more things of the same kind, as of animal or plant with respect to classification. 2. One of two or more muscles with the same function. [L. con-, with, + genus, race]

congenerous (kon-jen′er-us)
1. Having the same function; denoting certain muscles that are synergistic. 2. Derived from the same source, or of a similar nature. [see congener]

congenic (kon-jen′ik)
Relating to an inbred strain of animals produced by repeated crossing of one gene line onto another inbred (isogenic) line. [con- + G. genos, birth, + -ic]

congenital (kon-jen′i-tal)
Existing at birth, referring to certain mental or physical traits, anomalies, malformations, diseases, etc. which may be either hereditary or due to an influence occurring during gestation up to the moment of birth. SYN: congenitus. [L. congenitus, born with]

congenitus (kon-jen′i-tus)
SYN: congenital. [L.]

congested (kon-jes′ted)
Containing an abnormal amount of blood; in a state of congestion.

congestion (kon-jes′chun)
Presence of an abnormal amount of fluid in the vessels or passages of a part or organ; especially, of blood due either to increased influx or to an obstruction to outflow. SEE ALSO: hyperemia. [L. congestio, a bringing together, a heap, fr. con-gero, pp. -gestus, to bring together] active c. c. due to an increased flow of arterial blood to a part. brain c. increased volume of the intravascular compartment of the brain; often associated with brain swelling. SYN: encephalemia. functional c. hyperemia occurring during functional activity of an organ. SYN: physiologic c.. hypostatic c. c. due to pooling of venous blood in a dependent part. SYN: hypostasis (2) . passive c. c. caused by obstruction or slowing of the venous drainage, resulting in partial stagnation of blood in the capillaries and venules. physiologic c. SYN: functional c.. venous c. overfilling and distention of the veins with blood as a result of mechanical obstruction or right ventricular failure.

congestive (kon-jes′tiv)
Relating to congestion.

conglobate (kon-glo′bat)
Formed in a single rounded mass. [L. con-globo, pp. -atus, to gather into a globus, ball]

conglobation (kon-glo-ba′shun)
An aggregation of numerous particles into one rounded mass.

conglomerate (kon-glom′e-rat)
Composed of several parts aggregated into one mass. [L. conglomero, pp. -atus, to roll together, fr. glomus, a ball]

conglutinant (kon-gloo′ti-nant)
Adhesive, promoting the union of a wound. [L. con-glutino, pp. -atus, to glue together, fr. gluten, glue]




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