ar·ea (r´e-) [ L. ]
1. a limited space. 2. in anatomy, a specific surface or a region with a given function.


See also entries under region.

AI area, see
auditory a's.
AII area, see auditory a's.
acoustic areas, auditory a's.
area amygdaloi´dea ante´rior, anterior amygdaloid area, a poorly differentiated transition zone in the corticomedial part of the amygdaloid body, through which the nuclei are continuous with adjacent areas.
aortic area, the area on the thorax over the medial end of the right second costal cartilage.
association areas, areas of the cerebral cortex (excluding the primary areas) that are connected with each other and with the neothalamus by numerous fibers passing through the corpus callosum and the white matter of the hemispheres; these areas are responsible for the higher mental and emotional processes, such as memory, learning, speech, and the interpretation of sensations.
auditory areas, two contiguous areas of the temporal lobe in the region of the anterior transverse temporal gyrus (Brodmann areas 41 and 42); designated AI(first or primary auditory area) and AII(second or secondary auditory area).
auditory association area, a sensory association area for auditory stimuli.
auditory receiving areas, auditory a's.
Bamberger area, an area of cardiac dullness in the left intercostal region, suggestive of pericardial effusion.
bare area of liver, a. nuda hepatis.
basal seat area, denture-bearing a.
B-dependent area, thymus-independent a.
Betz cell area, primary somatomotor a.
brain area, cortical a.
Broca motor speech area, an area comprising parts of the opercular portion of the inferior frontal gyrus; injury to this area may result in a minor form of motor aphasia.
Broca parolfactory area, a. subcallosa.
Brodmann areas, areas of the cerebral cortex distinguished by hypothesized differences in the arrangement of their six cellular layers and identified by numbers; although the histologic basis is in dispute, the topographic numbering is widely used as a descriptor for mapping cortical locations that control different functions of the nervous system and the body.
catchment area, the geographical area that a specialized health care facility is responsible for serving.
area centra´lis, macula lutea.
area cerebrovasculo´sa, a membrane-covered, reddish, spongy mass, consisting of thin-walled blood vessels and variable amounts of ependyma, choroid plexus, and glial tissue, that replaces the forebrain in anencephaly.
cingulate area, the area comprising the cingulate gyrus and isthmus, an important component of the limbic system.
area coch´leae, TA alternative for a. cochlearis.
cochlear area, area cochlea´ris, the anterior part of the inferior portion of the fundus of the internal acoustic meatus, near the base of the cochlea; called also a. cochleae[TA alternative].
Cohnheim areas, dark, polygonal areas of myofibrils seen on cross-section of a poorly fixed muscle fiber.
contact area, any area at which two bodies or materials touch. Called also contact surface. See also proximal surface (def. 2), under surface.a. contingens dentis.
area contin´gens den´tis, contact area: the area of the mesial or distal surface of a tooth that touches the adjoining tooth.
cortical area, any portion of the cerebral cortex that can be differentiated functionally from its neighbors; see names of specific areas and see also cortex, field, and zone.
cribriform area of renal papilla, area cribro´sa papil´lae rena´lis, the tip of a renal pyramid, which is perforated by 10–25 openings for the papillary ducts.
area of critical definition, that part of an optic image within which the detail is clear.
denture-bearing area, denture foundation area, denture-supporting area, the surface of the oral tissues (residual alveolar ridge) that supports a denture. Called also basal seat a. and stress-bearing a.
dermatomic area, dermatome.
embryonic area, see under disc.
entorhinal area, Brodmann area 28, the inferior and posterior parts of the piriform area, including the caudal part of the parahippocampal gyrus.
eye area, see frontal eye field and occipital eye field.
area of facial nerve, a. nervi facialis.
areas of Forel, see under field.
fusion area, Panum a.
gastric areas, a´reae gas´tricae, small patches of gastric mucosa, 1 to 5 mm in diameter, separated by the plicae villosae and containing the foveolae gastricae (gastric pits).
germinal area, embryonic disc.
gustatory receiving area, the primary receiving area for taste sensations; thought to be in or near the opercular part of the postcentral gyrus.
hypoglossal area, area hypoglos´si, the portion of the mouth beneath the tongue.
hypophysiotropic area, the part of the hypothalamus that contains neurons that secrete hormones that regulate adenohypophysial cells.
hypothalamic area, anterior, area hypothalamica rostralis.
hypothalamic area, dorsal, area hypothalamica dorsalis.
hypothalamic area, intermediate, area hypothalamica intermedia.
hypothalamic area, lateral, area hypothalamica lateralis.
hypothalamic area, posterior, area hypothalamica posterior.
area hypothala´mica dorsa´lis, dorsal hypothalamic area: the most dorsal part of the hypothalamus, comprising the entopeduncular nucleus and the nucleus of the ansa lenticularis. Called also regio hypothalamica dorsalis and dorsal hypothalamic region.
area hypothala´mica interme´dia, intermediate hypothalamic area: the part of the hypothalamus comprising the lateral hypothalamic region and the following nuclei: arcuate, tuberal, ventromedial hypothalamic, dorsomedial hypothalamic, dorsal hypothalamic, posterior periventricular, and infundibular. Called also regio hypothalamica intermedia and intermediate hypothalamic region.
area hypothala´mica latera´lis, lateral hypothalamic area: a part of the intermediate hypothalamic area lateral to the fornix and the mammillothalamic fasciculus; called also regio hypothalamica lateralis and lateral hypothalamic region.
area hypothala´mica poste´rior, posterior hypothalamic area: the most posterior part of the hypothalamus, consisting of the lateral and medial nuclei of the mammillary body and the posterior hypothalamic nucleus. Called also regio hypothalamica posterior and posterior hypothalamic region.
area hypothala´mica rostra´lis, anterior hypothalamic area: the most anterior part of the hypothalamus, lying adjacent to the lamina terminalis and superior to the optic chiasm, and comprising the lateral and medial preoptic nuclei, the supraoptic and paraventricular nuclei, and the anterior hypothalamic nucleus; called also preoptic area or region, regio hypothalamica anterior, and anterior hypothalamic region.
impression area, the surface of the oral structures recorded in an impression.
insular area, the cortex of the insula.
intercondylar areas of tibia, see a. intercondylaris anterior tibiae and a. intercondylaris posterior tibiae.
area intercondyla´ris ante´rior ti´biae, anterior intercondylar area of tibia: the broad area between the superior articular surfaces of the tibia; called also fossa intercondyloidea anterior tibiae, anterior intercondylar fossa of tibia, and patellar fossa of tibia.
area intercondyla´ris poste´rior ti´biae, posterior intercondylar area of tibia: a deep notch separating the condyles on the posterior surface of the tibia; called also posterior intercondylar a., fossa intercondyloidea posterior tibiae, posterior intercondylar fossa of tibia, and popliteal fossa of tibia.
Kiesselbach area, an area on the anterior part of the nasal septum above the intermaxillary bone, which is richly supplied with blood vessels and is a common site of nosebleed; called also Little a.
Laimer-Haeckerman area, a triangular area of sparse musculature just below the pharyngoesophageal junction, where Zenker diverticulum most frequently develops.
language area, any nerve center of the cerebral cortex, usually in the dominant hemisphere, controlling the understanding or use of language.
Little area, Kiesselbach a.
area of Martegiani, a slightly enlarged, funnel-shaped space anterior to the optic disk, marking the posterior opening of the hyaloid canal.
area medullovasculo´sa, a median elongated area of vascular granulation-like tissue in rachischisis.
mesobranchial area, the pharyngeal floor in the embryo, between the pharyngeal arches and pouches of each side.
midarm muscle area, a value used to estimate lean body mass, calculated by the formula

where n is 10 for males and 6.5 for females.
mirror area, the reflecting surface of the cornea and lens when illuminated through the slit lamp.
motor area, any area of the cerebral cortex primarily involved in stimulating muscle contractions; often used alone to refer to the primary somatomotor area. See also premotor a., sensorimotor a., and Broca motor speech a.
motor speech area, see Broca motor speech a. and Wernicke second motor speech a.
area ner´vi facia´lis, area of facial nerve: the part of the fundus of the internal acoustic meatus where the facial nerve enters the facial canal.
area nu´da he´patis, bare area of liver: a large part of the diaphragmatic surface of the liver that lacks a peritoneal covering; its boundaries are formed by the coronary ligament of the liver and the triangular ligaments.
olfactory area, a general area, including the olfactory bulb, tract, and trigone, the anterior portion of the gyrus cinguli, and the uncus.substantia perforata rostralis.
Panum area, the area on the retina of one eye over which a point-sized image can range and still provide a stereoscopic image with a specific point of stimulus on the retina of the other eye. Called also fusion a.
parastriate area, Brodmann area 18, an area of the occipital cortex partly surrounding the striate cortex and having some of the functions of an association area for visual sensations.
area pellu´cida, the central clear part of the embryonic disc, as seen in the bird egg.
periamygdaloid area, the intermediate part of the piriform area, between the piriform area and the entorhinal area; it covers the amygdaloid body.
peristriate area, Brodmann area 19, an area of the occipital cortex partly surrounding the striate cortex and having some functions of an association area for visual sensations.
piriform area, an area in the rhinencephalon, pear-shaped in some species but not in humans; it includes the lateral olfactory process or gyrus, the limen insulae, the uncus, and part of the parahippocampal gyrus; subdivided into the prepiriform area, the periamygdaloid area, and the entorhinal area. Called also piriform lobe.
postcentral area, the sensory area just posterior to the central sulcus of the cerebral hemisphere, the primary receptive area for general sensations; called also postrolandic a. and somesthetic cortex.
post dam area, posterior palatal seal a.
posterior palatal seal area, the soft tissues along the junction of the hard and soft palates on which pressure can be applied by a denture to aid in its retention; called also post dam a.
area postre´ma, a small tongue-shaped area on the lateral wall of the fourth ventricle, between the funiculus separans and the tuberculum gracile, in which the blood-brain barrier may be modified. See also circumventricular organs, under organ.
postrolandic area, postcentral a.
precentral area, primary somatomotor a.
prefrontal area, the cortex of the frontal lobe immediately in front of the premotor cortex, concerned chiefly with associative functions.
premotor area, the motor cortex of the frontal lobe immediately in front of the precentral gyrus.
preoptic area, a. preoptica.area hypothalamica rostralis.
area preop´tica, preoptic area: several groups of cells in the median plane immediately below the rostral commissure of the telencephalon that are functionally related to the hypothalamus; called also preoptic region.
prepiriform area, the anterior part of the piriform area, consisting primarily of the lateral olfactory gyrus.
pressure area, an area subjected to excessive pressure with consequent displacement of tissue or fluid.
pretectal area, area pretecta´lis, an area at the junction of the mesencephalon and diencephalon, extending from a position dorsolateral to the commissure of the epithalamus toward the cranial colliculus, within which is situated the pretectal nucleus; called also pretectal region.
primary areas, areas of the cerebral cortex comprising the motor and sensory (primary receiving) areas. Cf. association a's.
primary receiving areas, primary receptive areas, the areas of the cerebral cortex that receive the thalamic projections of the primary sensory modalities. Called also sensory a's or centers.
primary somatomotor area, an area in the posterior part of the frontal lobe just anterior to the central sulcus, corresponding to Brodmann area 4; different regions control motor activity of specific parts of the body. Called also Betz cell a., motor a., precentral a., rolandic a., and Rolando zone.
projection areas, those areas of the cerebral cortex that receive the most direct projection of the sensory systems of the body.
pyriform area, piriform a.
receiving areas, receptive areas, primary receiving a's.
relief area, the portion of the surface of the mouth upon which pressures or forces are reduced or eliminated in prosthodontic therapy. See also relief (def. 3).
rest area, the prepared surface of a tooth or fixed restoration into which the rest fits, giving support to a removable partial denture. Called also rest seat.
area retrooliva´ris, retroolivary area, the most caudal part of the lateral region of the medulla oblongata, towards the posterolateral sulcus.
rolandic area, primary somatomotor a.
rugae area, the portion of the mouth in which rugae are found; called also rugae zone.
SI area, first somatosensory a.
SII area, second somatosensory a.
saddle area, the edentulous portion of the dental arch upon which a fixed or removable prosthesis rests.
sensorimotor area, the cortex of the pre- and postcentral gyri—the motor area and the primary receptive area for general sensations, respectively.
sensory areas, primary receptive a's.
sensory association area, an association area around the borders of a primary receptive area, where sensory stimuli are interpreted.
septal area, the area on either cerebral hemisphere comprising the area subcallosa and the corresponding half of the septum pellucidum; the area has olfactory, hypothalamic, and hippocampal connections.
silent area, an area of the brain in which pathologic conditions may occur without producing symptoms obvious to the clinician.association a.
somatic sensory area, somatosensory area, either of the two cortical regions where conscious perception of somatic sensations occurs, called the first or primary somatosensory area and the second or secondary somatosensory area.
somatosensory area, first, somatosensory area, primary, the cortical projection area in the postcentral gyrus for receiving into consciousness somatosensory information initiated by stimulation of receptors in the skin, joints, muscles, and viscera. Called also SI a.
somatosensory area, second, somatosensory area, secondary, a cortical projection area lateral and posterior to the primary somatosensory area; it receives somatic sensations mainly from the skin, particularly sensations of pain and of movement across the skin. Called also SII a.
somesthetic area, somatosensory a.
area spina´lis X, the innermost region of the layers of the spinal cord as described by Rexed; see Rexed laminae, under lamina. Called also lamina spinalis X[TA alternative].
stress-bearing area, the portion of the mouth capable of providing support for a denture.surfaces of oral structures which resist forces, strains, or pressures brought upon them during function.denture-bearing a.
striate area, see under cortex.
strip area, a strip of cortex between the motor and premotor areas thought to be suppressor in function.
area subcallo´sa, subcallosal area, a small area of cortex on the medial surface of each cerebral hemisphere, between the anterior and posterior parolfactory sulci.
area of superficial cardiac dullness, a triangular area of dullness observed on percussion of the chest, corresponding to that area of the heart not covered by lung tissue.
supplementary areas, small motor and sensory areas of the cerebral cortex in addition to the primary areas.
supplementary motor area, an area in the gyrus frontalis medius just above the cingulate gyrus and anterior to the part of the first somatomotor area that mediates movements of the lower extremity.
supporting area, the surface of the mouth available for support of a denture.those areas of the maxillary and mandibular edentulous ridges which are considered best suited to carry the forces of mastication when the dentures are in function.
suppressor areas, cortical areas whose activation is thought to suppress or prevent movement; see also strip a.
taste receiving area, gustatory receiving a.
T-dependent area, thymus-dependent a.
thymus-dependent area, any of the areas of the peripheral lymphoid organs populated by T lymphocytes, e.g., the periarteriolar lymphatic sheath in the spleen, the paracortex in lymph nodes, and the parafollicular areas of gut-associated lymphoid tissue. Called also paracortex, T-dependent a., and tertiary cortex.
thymus-independent area, any of the areas of the peripheral lymphoid organs populated by B lymphocytes, e.g., the lymph nodules (lymphoid follicles) of the spleen, lymph nodes, and gut-associated lymphoid tissue. Called also B-dependent a. and T-independent a.
T-independent area, thymus-independent a.
trigger area, see under zone.
area under the curve, the area enclosed between a probability curve with nonnegative values and the axis of the quality being measured; of the total area under a curve, the proportion that falls between two given points on the curve defines a probability density function (see under function).
vagus area, trigonum nervi vagi.
vestibular area, a rounded triangular elevation lateral to foveae of the fourth ventricle over which pass the striae medullares; it extends into the lateral recess, where it forms the auditory, or acoustic, tubercle.
vestibular area of internal acoustic meatus, inferior, a. vestibularis inferior meatus acustici interni.
vestibular area of internal acoustic meatus, superior, a. vestibularis superior meatus acustici interni.
area vestibula´ris infe´rior mea´tus acus´tici inter´ni, inferior vestibular area of internal acoustic meatus: the lower portion of the fundus of the internal acoustic meatus, transmitting fibers of the saccular nerve.
area vestibula´ris supe´rior mea´tus acus´tici inter´ni, superior vestibular area of internal acoustic meatus: the upper portion of the fundus of the internal acoustic meatus, transmitting fibers of the utricular and superior ampullary nerves.
visual area, see under cortex.
visual area, first, striate cortex.
visual area, second, parastriate a.
visual area, third, peristriate a.
visual association areas, the peristriate and parastriate areas considered together.
visual receiving area, visual cortex.
visuopsychic areas, visual association a's.
visuosensory area, striate cortex.
vocal area, rima glottidis.
watershed area, any of several areas over the convexities of the cerebral or cerebellar hemispheres, distant from the circle of Willis, where the vascular beds of two cerebral arteries meet and form anastomoses. At times of prolonged systemic hypotension, these are particularly susceptible to infarction, with those fed by the largest arterial branches being the first affected. See also watershed infarction, under infarction.
Wernicke area, Wernicke second motor speech area, originally a term denoting a language center thought to be confined to the posterior part of the superior temporal gyrus adjacent to the transverse temporal gyri; the term now includes a wider zone that encompasses the supramarginal and angular gyri as well; called also Wernicke field or zone.