|Medical Dictionary - Dictionary of Medicine and Human Biology|
The act of reducing a fault; the elimination of an unfavorable quality. occlusal c. 1. the c. of malocclusion, by whatever means is employed; 2. elimination of disharmony of occlusal contacts. spontaneous c. of placenta previa the upward “migration” of the placenta away from the internal os by the differential growth rates of upper and lower uterine segments.
1. Counteracting, modifying, or changing what is injurious. 2. A drug that modifies or corrects an undesirable or injurious effect of another drug. SYN: corrigent. [L. cor-rigo (conr-), pp. -rectus, to set right, fr. rego, to keep straight]
1. The mutual or reciprocal relation of two or more items or parts. 2. The act of bringing into such a relation. 3. The degree to which variables change together. product-moment c. a statistical procedure which yields the c. coefficient referred to as r (−1.00 to +1.00) and involves the actual values, rather than the ranks (rank order) of the measurements. rank-difference c. the relationship between paired series of measurements, each ranked according to magnitude, which yields a coefficient known as rho; the value of rho varies from zero (no relationship) to +1.00 (perfect relationship).
See under line.
In optics, those points on each retina that have the same visual direction. abnormal c. SYN: anomalous retinal c.. anomalous retinal c. abnormal c., a condition, frequent in strabismus, in which corresponding retinal points do not have the same visual direction; the fovea of one eye corresponds to an extrafoveal area of the fellow eye. SYN: abnormal c.. dysharmonious retinal c. a type of anomalous retinal c. in which the angle of the visual direction of the two retinas is different from the objective angle of the strabismus. harmonious retinal c. a type of anomalous retinal c. in which the angle of the visual direction of the two retinas is equal to the objective angle of strabismus.
Sir Dominic J., Irish pathologist and clinician, 1802–1880. See C. disease, C. pulse, C. sign.
The cyclic system of four pyrrole rings forming corrinoids, which are the central structure of the vitamins B12 and related compounds, differing from porphin (porphyrin) in that two of the pyrrole rings are directly linked (C-19 to C-1). [fr. core (of vitamin B12 molecule)]
A compound containing a corrin ring.
To cause, or to be affected by, corrosion.
1. Gradual deterioration or consummation of a substance by another, especially by biochemical or chemical reaction. Cf.:erosion. 2. The product of corroding, such as rust. [L. cor-rodo (conr-), pp. -rosus, to gnaw]
1. Causing corrosion. 2. An agent that produces corrosion; e.g., a strong acid or alkali.
corrugator (kor′u-ga-ter, -tor)
A muscle that draws together the skin, causing it to wrinkle. [L. cor-rugo (conr-), pp. -atus, to wrinkle, fr. ruga, a wrinkle]
cortex, gen. corticis, pl .cortices (kor′teks, -ti-sis, -ti-sez) [TA]
The outer portion of an organ, such as the kidney, as distinguished from the inner, or medullary, portion. [L. bark] adrenal c. SYN: c. of suprarenal gland. agranular c. cerebral c.. association c. generic term denoting the large expanses of the cerebral c. that are not sensory or motor in the customary sense, but are involved in advanced stages of sensory information processing, multisensory integration, or sensorimotor integration. SEE ALSO: cerebral c.. SYN: association areas. auditory c. the region of the cerebral c. that receives the auditory radiation from the medial geniculate body, a thalamic cell group receiving auditory input from the cochlear nuclei in the rhombencephalon; it corresponds approximately to Brodmann areas 41 and 42 and is tonotopically organized. SYN: auditory area. cerebellar c. the thin gray surface layer of the cerebellum, consisting of an outer molecular layer or stratum moleculare, a single layer of Purkinje cells (the Purkinje cell layer), and an inner granular layer or stratum granulosum. SYN: c. cerebelli [TA] . c. cerebelli [TA] SYN: cerebellar c.. cerebral c. [TA] the gray cellular mantle (1–4 mm thick) covering the entire surface of the cerebral hemisphere of mammals; characterized by a laminar organization of cellular and fibrous components such that its nerve cells are stacked in defined layers varying in number from one, as in the archicortex of the hippocampus, to five or six in the larger neocortex; the outermost (molecular or plexiform) layer contains very few cell bodies and is composed largely of the distal ramifications of the long apical dendrites issued perpendicularly to the surface by pyramidal and fusiform cells in deeper layers. From the surface inward, the layers as classified in K. Brodmann's parcellation are: 1) molecular layer [TA]; 2) external granular layer [TA]; 3) external pyramidal layer [TA]; 4) internal granular layer [TA]; 5) internal pyramidal layer [TA]; and 6) multiform layer [TA], many of which are fusiform. This multilaminate organization is typical of the neocortex (homotypic c.; isocortex [TA] in O. Vogt terminology), which in humans covers the largest part by far of the cerebral hemisphere. The more primordial heterotypic c. or allocortex (Vogt) has fewer cell layers. A form of c. intermediate between isocortex and allocortex, called juxtallocortex (Vogt) covers the ventral part of the cingulate gyrus and the entorhinal area of the parahippocampal gyrus. On the basis of local differences in the arrangement of nerve cells (cytoarchitecture), Brodmann outlined 47 areas in the cerebral c. which, in functional terms, can be classified into three categories: motor c. (areas 4 and 6), characterized by a poorly developed internal granular layer (agranular c.) and prominent pyramidal cell layers; sensory c., characterized by a prominent internal granular layer (granular c. or koniocortex) and comprising the somatic sensory c. (areas 1 to 3), the auditory c. (areas 41 and 42), and the visual c. (areas 17 to 19); and association c., the vast remaining expanses of the cerebral c.. SYN: c. cerebri [TA] , pallium [TA] , brain mantle, mantle (2) . c. cerebri [TA] SYN: cerebral c.. deep c. SYN: paracortex. dysgranular c. the region of the cerebral c. that is transitional between the agranular c. of the precentral gyrus and the granular frontal c. (Brodmann area 8). fetal adrenal c. an extensive area of the adrenal gland present in primates during fetal life and for a short period after birth; located between the definitive c. and the medulla, it contains large steroid-secreting cells arranged in a reticular pattern; involution of this zone in humans is largely completed by three months after birth. SYN: androgenic zone (2) , fetal reticularis (1) , fetal zone, provisional c.. frontal c. c. of the frontal lobe of the cerebral hemisphere; 1. originally, the entire cortical expanse anterior to the central sulcus, including the agranular motor and premotor c. (Brodmann areas 4 and 6), the dysgranular c. (area 8), and the granular frontal (prefrontal) c. anterior to the latter; 2. now more often refers to the granular frontal (prefrontal) c.. SYN: frontal area. c. glandulae suprarenalis [TA] SYN: c. of suprarenal gland. granular c. cerebral c.. c. of hair shaft the principal structural component of the hair shaft, composed of closely packed fusiform keratinized cells and invested by the cuticula pili. heterotypic c. SYN: allocortex. homotypic c. SYN: isocortex. insular c. SYN: insula (1) . laminated c. neocortex [TA] and allocortex [TA]. c. of lens [TA] the softer, more superficial part of the lens of the eye that encloses the central part or nucleus; its refractive power is less than that of the nucleus. SYN: c. lentis [TA] . c. lentis [TA] SYN: c. of lens. c. of lymph node [TA] the outer portion of the lymph node underneath its capsule, consisting of fibrous trabeculae separating densely packed masses of lymphocytes arranged in nodules and separated from the trabeculae and capsule by lymph sinuses. SYN: c. nodi lymphatici [TA] . mastoid c. the plate of bone on the lateral surface of the mastoid process of the temporal bone. motor c. the region of the cerebral c. most nearly immediately influencing movements of the face, neck and trunk, and arm and leg; it corresponds approximately to Brodmann areas 4 and 6 of the precentral gyrus and immediately adjacent portions of the superior and middle frontal gyri; its effects upon the motor neurons innervating the skeletal musculature are mediated by corticospinal fibers (pyramidal tract) and corticonuclear fibers and are particularly essential for the human capacity to perform finely graded movements of arm and leg. SYN: excitable area, motor area, Rolando area. c. nodi lymphatici [TA] SYN: c. of lymph node. olfactory c. SYN: piriform c.. orbitofrontal c. the cerebral c. covering the basal surface of the frontal lobes. SYN: fronto-orbital area. ovarian c. [TA] the layer of the ovarian stroma lying immediately beneath the tunica albuginea, composed of connective tissue cells and fibers, among which are scattered primary and secondary (antral) follicles in various stages of development; the c. varies in thickness according to the age of the individual, becoming thinner with advancing years. SYN: c. ovarii [TA] , c. of ovary. c. ovarii [TA] SYN: ovarian c.. c. of ovary SYN: ovarian c.. parastriate c. visual c.. peristriate c. visual c.. piriform c. the olfactory c., corresponding to the rostral half of the uncus; receiving its major afferents from the olfactory bulb, it is classified as allocortex. SEE ALSO: cerebral c.. SYN: olfactory c., piriform area. prefrontal c. frontal c.. premotor c. a somewhat ill-defined term usually referring to the agranular c. of Brodmann area 6. SYN: premotor area. primary visual c. visual c.. provisional c. SYN: fetal adrenal c.. renal c. [TA] the part of the kidney consisting of renal lobules in the outer zone beneath the capsule and also the lobules of the renal columns that are extensions inward between the pyramids; contains the renal corpuscles and the proximal and distal convoluted tubules. SYN: c. renalis [TA] . c. renalis [TA] SYN: renal c.. secondary sensory c. a cortical region occupying the parietal operculum (upper lip of the lateral sulcus) closely posterior to the foot of the postcentral gyrus; like the primary somatic-sensory c. of the postcentral gyrus, this region receives sensory impulses originating in face, trunk, and limbs; projections to the s.s.c. are from the ventral basal complex (ventral posteromedial and posterolateral thalamic nuclei) and from the primary somesthetic c.. secondary visual c. visual c.. sensory c. formerly denoting specifically the somatic sensory c., but now used to refer collectively to the somatic sensory, auditory, visual, and olfactory regions of the cerebral c.. somatic sensory c., somatosensory c. the region of the cerebral c. receiving the somatic sensory radiation from the ventrobasal nucleus of the thalamus; it represents the primary cortical processing mechanism for sensory information originating at the body surfaces (touch) and in deeper tissues such as muscle, tendons, and joint capsules (position sense); it corresponds approximately to Brodmann areas 1, 2, 3 on the postcentral gyrus. SYN: somesthetic area. striate c. visual c.. supplementary motor c. a region from which, by electrical stimulation, the musculature of all bodily parts can be activated, as it also can by stimulation of the motor c. of the precentral gyrus; the region corresponds approximately to the expansion of Brodmann area 6 over the medial surface of the cerebral hemisphere; this area has largely a bilateral representation and is concerned primarily with tonic and postural motor activities. suprarenal c. SYN: c. of suprarenal gland. c. of suprarenal gland [TA] the outer part of the adrenal gland, consisting of three zones from without inward: zona glomerulosa, zona fasciculata, and zona reticularis; this part of the adrenal c. yields steroid hormones such as corticosterone, deoxycorticosterone, and estrone. SYN: c. glandulae suprarenalis [TA] , adrenal c., suprarenal c.. temporal c. SYN: temporal lobe. tertiary c. SYN: paracortex. c. thymi [TA] SYN: c. of thymus. c. of thymus [TA] the outer part of a lobule of the thymus; it surrounds the medulla and is composed of masses of closely packed lymphocytes. SYN: c. thymi [TA] . visual c. the region of the cerebral c. occupying the entire surface of the occipital lobe, and composed of Brodmann areas 17–19. Area 17 (which is also called striate c. or area because the line of Gennari is grossly visible on its surface) is the primary visual c., receiving the visual radiation from the lateral geniculate body of the thalamus. The surrounding areas 18 (parastriate c. or area) and 19 (peristriate c. or area) are probably involved in subsequent steps of visual information processing; area 18 is referred to as the secondary visual c.. SYN: visual area.
A mineralocorticoid hormone from the adrenal cortex.
Marquis Alfonso, Italian anatomist, 1822–1876. See C. arch, C. canal, C. cells, under cell, C. ganglion, C. membrane, C. organ, C. pillars, under pillar, C. rods, under rod, C. auditory teeth, under tooth, C. tunnel, pillar cells of C., under cell.
Relating to a cortex.
In phylogenesis, the migration of function from subcortical centers to the cortex. SYN: encephalization, telencephalization.
An osteotomy through the cortex at the base of the dentoalveolar segment, which serves to weaken the resistance of the bone to the application of orthodontic forces.
Removal of a specific portion of the cerebral cortex. [cortic- + G. ektome, excision]
Plural of cortex.
Passing in a direction toward the outer surface; denoting nerve fibers conveying impulses toward the cerebral cortex. SYN: corticoafferent. [L. cortex, rind, bark, + peto, to seek]
See c. fibers, under fiber, corticonuclear fibers, under fiber.
Passing in a direction away from the outer surface; denoting especially nerve fibers conveying impulses away from the cerebral cortex. SYN: corticifugal, corticoefferent. [L. cortex, rind, bark, + fugio, to flee]
1. Having an action similar to that of a hormone of the adrenal cortex. 2. Any substance exhibiting this action. 3. SYN: corticosteroid.
Cortical and medial; specifically used to refer to one of the two major cytological divisions of the amygdaloid complex. See corpus amygdaloideum.
A steroid produced by the adrenal cortex ( i.e., adrenal corticoid); a corticoid containing a steroid. SYN: adrenocorticoid, corticoid (3) , cortin.
A corticosteroid that induces some deposition of glycogen in the liver, sodium conservation, and potassium excretion; the principal glucocortoid in the rat.
Pertaining to cortex and thalamus; the term is applied to fibers projecting from the cerebral cortex to the thalamus, the c. fibers [TA].
A cell of the adenohypophysis that produces adrenocorticotropic hormone (ACTH).
1. SYN: adrenocorticotropic hormone. 2. SYN: β-c.. [G. trope, a turning] c.-zinc hydroxide purified c. absorbed on zinc hydroxide; same uses as c. but with a prolonged duration of action.
Name for a family of nonenveloped, ether-sensitive bacterial viruses of medium size, with a lipid-containing capsid and genome of circular, double-stranded DNA (MW 5 × 106), which accounts for about 12% of virion weight.
Only genus in family of Corticoviridae.
The fluid in Corti tunnel.
SYN: hydrocortisone. c. acetate SYN: hydrocortisone acetate.
A glucocorticoid not normally secreted in significant quantities by the human adrenal cortex. Endogenously, it is probably a metabolite of hydrocortisone but exhibits no biological activity until converted to hydrocortisone (cortisol); it acts upon carbohydrate metabolism and influences the nutrition and growth of connective (collagenous) tissues. It was the first glucocorticoid available for therapy. SYN: Wintersteiner compound F.
Native crystalline aluminum oxide. [Hind. kurand]
Corvisart des Marets
Baron Jean N., French clinician, 1755–1821. See Corvisart facies.
Denoting the flowerlike clustering configuration of skin lesions in granulomatous diseases ( e.g., syphilis, tuberculosis). [L. corymbus, cluster, garland]
Plural of corynebacterium.
Any one of the bacteriophages specific for corynebacteria. β c. a DNA-containing bacteriophage that induces toxigenicity in strains of Corynebacterium diphtheriae that are lysogenic for its prophage. SYN: β phage.
A genus of nonmotile (except for some plant pathogens), aerobic to anaerobic bacteria (family Corynebacteriaceae) containing irregularly staining, Gram-positive, straight to slightly curved, often club-shaped rods which, as a result of snapping division, may show a picket fence arrangement. These organisms are widely distributed in nature. The best known species are parasites and pathogens of humans and domestic animals. The type species is C. diphtheriae. [G. coryne, a club, + bacterium, a small rod] C. acnes former name for Propionibacterium acnes. C. amycolatum a species found as normal skin flora, it causes septicemia, frequently associated with venous access devices, and has also been recovered from urinary tract infections and mixed flora abscesses. C. diphtheriae a bacterial species that causes diphtheria and produces a powerful exotoxin causing degeneration of various tissues, notably myocardium, in humans and experimental animals and catalyzes the ADP-ribosylation of elongation factor II; virulent strains of this organism are lysogenic; it is commonly found in membranes in the pharynx, larynx, trachea, and nose in cases of diphtheria; it is also found in apparently healthy pharynx and nose in carriers, and is occasionally found in the conjunctiva and in superficial wounds; it occasionally infects the nasal passages and wounds of horses; it is the type species of the genus C.. SYN: Klebs-Loeffler bacillus, Loeffler bacillus. C. equi SYN: Rhodococcus equi. C. glucuronolyticum a species isolated from patients with urinary tract infections. C. haemolyticum former name for Arcanobacterium haemolyticum. C. hofmannii former name for C. pseudodiphtheriticum. C. jeikeium species associated with septicemia and skin lesions in immunocompromised patients, especially associated with venous access devices. C. matruchotii a species recovered in mixed infections from human eye specimens. C. minutissimum a bacterial species that is a component of normal skin flora, causes erythrasma in humans. C. parvum former name for Propionibacterium acnes. C. pseudodiphtheriticum a rarely pathogenic species found in normal throats. SYN: Hofmann bacillus. C. striatum a bacterial species found in nasal mucus and in the throat; also found in udders of cows with mastitis; pathogenic to laboratory animals; a rare cause of infection to immnocompromised patients. C. xerosis a bacterial species found in normal and diseased conjunctiva; there is no evidence that this organism is pathogenic.
corynebacterium, pl .corynebacteria (ko-ri′ne-bak-ter′e-um, -a)
A vernacular term used to refer to any member of the genus C..
SYN: acute rhinitis. [G.] allergic c. SYN: hay fever.
Obsolete name for Rhinovirus.
A concern in therapeutics for the appearance of the patient; i.e., an operation that improves appearance. [G. kosmesis, an adorning, fr. kosmeo, to order, arrange, adorn, fr. kosmos, order]
1. Relating to cosmesis. 2. Relating to the use of cosmetics.
Composite term for a variety of camouflages applied to the skin, lips, hair, and nails for purposes of beautifying in accordance with cultural dictates.
A recombinantly engineered plasmid, a circular DNA containing, in order: a plasmid origin of replication and a drug-resistance marker, the cos (cohesive end) site from bacteriophage λ, and a fragment of eukaryotic DNA to be cloned; cosmids are constructed to permit cloning of fragments of up to about 40,000 base pairs in length, with one or more unique restriction sites being necessary to facilitate cloning.
In the biologic sciences, a term denoting worldwide distribution. [G. kosmos, universe, + polis, city-state]
costa, gen. and pl. costae (kos′ta, -te)
1. [TA] [I–XII]. SYN: rib [I–XII]. 2. A rodlike internal supporting organelle that runs along the base of the undulating membrane of certain flagellate parasites such as Trichomonas. SYN: basal rod. [L.] c. cervicalis [TA] SYN: cervical rib. costae fluctuantes [XI–XII] SYN: floating ribs [XI–XII], under rib [I–XII]. costae fluitantes SYN: floating ribs [XI–XII], under rib [I–XII]. c. lumbalis [TA] c. prima [I] [TA] SYN: first rib [I]. costae spuriae [VII–XII] [TA] SYN: false ribs, under rib [I–XII]. costae verae [I–VII] [TA] SYN: true ribs [I–VII], under rib [I–XII].
Relating to a rib.
SYN: pleurodynia. [L. costa, rib, + G. algos, pain]
Excision of a rib. [L. costa, rib, + G. ektome, excision]
James B., U.S. otolaryngologist, 1895–1962. See C. syndrome.
SYN: costal cartilage.
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