1. An often arbitrarily limited portion of the surface of the body. SEE ALSO: space, zone. 2. A portion of the body having a special nervous or vascular supply, or a part of an organ having a special function. SEE ALSO: area, space, spatium, zone. SYN: regio [TA]. [L. regio]
- abdominal regions [TA] the topographic subdivisions of the abdomen; based on subdividing the abdomen by the transpyloric, interspinous, and midclavicular planes; including the right and left hypochondrium, right and left flank or lateral, right and left groin or inguinal, and the unpaired epigastric, umbilical, and pubic regions. SYN: regiones abdominis [TA], abdominal zones.
- ankle r. [TA] the r. of the lower limb between the leg (crus) and the foot (pes). SYN: regio tarsalis [TA], regio talocruralis.
- anterior r. of arm [TA] area between deltoid r. superiorly and anterior r. of elbow inferiorly. SYN: regio brachii anterior [TA], regio brachialis anterior, anterior surface of arm, facies anterior brachii, facies brachialis anterior.
- anterior cervical r. [TA] the area of the neck bounded by the mandible, the anterior border of the sternocleidomastoid muscle, and the anterior midline of the neck; it is subdivided into carotid, muscular, submandibular, and submental triangles. SYN: regio cervicalis anterior [TA], anterior triangle of neck, trigonum cervicale anterius, trigonum colli anterius, anterior r. of neck.
- anterior r. of elbow [TA] the area in front of the elbow, including the cubital fossa. SYN: regio cubitalis anterior [TA], anterior cubital r., anterior surface of elbow, facies cubitalis anterior.
- anterior r. of forearm [TA] the area between the radial and ulnar borders of the forearm anteriorly. SYN: regio antebrachii anterior [TA], regio antebrachialis anterior, anterior antebrachial r., anterior surface of forearm, facies antebrachialis anterior, facies anterior antebrachii.
- anterior r. of knee [TA] the anterior r. of the knee. SYN: regio genus anterior [TA], anterior knee r..
- anterior and lateral thoracic regions [TA] the topographic divisions of the chest : presternal, pectoral, and axillary. SYN: regiones thoracicae anteriores et laterales [TA], regions of chest.
- anterior r. of leg [TA] the anterior surface of the inferior limb between the knee and the ankle. SYN: regio cruris anterior [TA], anterior crural r., anterior surface of leg, facies anterior cruris, facies cruralis anterior.
- anterior r. of thigh [TA] the front of the thigh, including the femoral triangle. SYN: regio femoris anterior [TA], anterior surface of thigh, facies femoralis anterior.
- anterior r. of wrist [TA] the anterior part of the wrist. SYN: regio carpalis anterior [TA], anterior carpal r..
- regions of back [TA] the topographic regions of the back of the trunk, including the vertebral r., sacral r., scapular r., infrascapular r., and lumbar r.. SYN: regiones dorsales [TA], regiones dorsi.
- buccal r. [TA] the r. of the cheek, corresponding approximately to the outlines of the underlying buccinator muscle. SYN: regio buccalis [TA].
- calcaneal r. SYN: heel r..
- chromosomal r. that part of a chromosome defined either by anatomical details, notably banding, or by its linkages (linkage group).
- complementarity determining regions that part of an antibody or T cell receptor variable r. that binds with antigen or antigen/major histocompatibility molecule.
- constant r. immunoglobulin.
- deltoid r. [TA] the lateral aspect of the shoulder demarcated by the outlines of the deltoid muscle. SYN: regio deltoidea [TA].
- epigastric r. [TA] the r. of the abdomen located between the costal margins and the subcostal plane. (TA lists this term as synonymous with epigastric fossa. SYN: epigastrium [TA], regio epigastrica.
- face r. [TA] the topographic subdivisions of the face, including nasal, oral, mental, orbital, infraorbital, buccal, parotid, and zygomatic. SYN: regio facialis [TA], regions of face.
- framework r. in immunology, a conserved sequence of amino acid s on either side of the hypervariable regions in the variable domains of an immunoglobulin chain.
- frontal r. of head [TA] the surface r. of the head corresponding to the outlines of the frontal bone. SYN: regio frontalis capitis [TA].
- regions of head [TA] the topographic division of the cranium in relation to the bones of the cranial vault; the regions include frontal, parietal, occipital, temporal, auricular, mastoid, and facial. SYN: regiones capitis [TA].
- hinge r. 1. that part of a tRNA structure that is deformed, bending a “cloverleaf” (two-dimensional) model to form an “L” model (crystal form, as seen by electron microscopy); 2. in an immunoglobulin, a short sequence of amino acid s that lies between two longer sequences and allows the latter to bend about the former.
- hypervariable regions (hi-per′var-i-a-ble) the regions of the immunoglobulin molecule that contain most of the residues involved in the antibody binding site.
- hypochondriac r. the r. on each side of the abdomen covered by the costal cartilages; it is lateral to the epigastric r.. SYN: hypochondrium [TA], regio hypochondriaca.
- I r. that area of the H-2 complex of mice that contains Class II major histocompatibility complex genes.
- inframammary r. [TA] the r. of the chest (portion of pectoral r.) inferior to the mammary gland. SYN: regio inframammaria [TA].
- infraorbital r. [TA] the facial r. below the orbit and lateral to the nose on each side. SYN: regio infraorbitalis [TA].
- infrascapular r. [TA] the r. of the back lateral to the vertebral r. and below the scapula. SYN: regio infrascapularis [TA].
- r. of interest in computed tomography or other computerized imaging, an interactively selected portion of the image, the individual or average pixel values of which can be displayed numerically.
- intermediate r. [TA] SYN: intermediate column.
- intermediate hypothalamic r. intermediate hypothalamic area.
- K r. carbons 9 and 10 of the phenanthrene ring system; thought by some to be the reactive spot in the various hydrocarbon carcinogens.
- lateral cervical r. [TA] the r. of the neck bounded by the sternocleidomastoid muscle, the trapezius muscle, and the upper border of the clavicle, including the omoclavicular triangle. SYN: regio cervicalis lateralis [TA], posterior triangle of neck, trigonum cervicale posterius, trigonum colli laterale, lateral r. of neck.
- lateral hypothalamic r. extends throughout most of the rostrocaudal extent of the hypothalamus lateral to the column of the fornix; includes lateral tuberal nuclei, tuberomamillary nuclei, and diffuse populations of cells.
- regions of lower limb [TA] the topographic divisions of the lower limb : gluteal, hip, femoral, knee, leg, ankle, and foot. SYN: regiones membri inferioris [TA], regions of inferior limb.
- lumbar r. [TA] the r. of the back lateral to the vertebral r. and between the rib cage and the pelvis. SYN: regio lumbalis [TA].
- mammary r. [TA] the r. of the chest (pectoral r.) that includes the breast. SYN: regio mammaria [TA].
- nucleolus organizer r. an arrangement of the DNA coding for the production of ribosomal RNA (rRNA).
- occipital r. of head [TA] the surface r. of the head corresponding to the outlines of the occipital bone. SYN: regio occipitalis capitis [TA].
- olfactory r. of mucosa of nose [TA] epithelium containing nerve cells whose axons form the filaments of the olfactory nerve; the lamina propria contains numerous olfactory glands (Bowman) that open to the surface. SYN: olfactory mucosa.
- olfactory r. of nasal mucosa [TA] the specialized olfactory receptive area that includes the upper one-third of the nasal septum and the lateral wall above the superior concha; it is lined with olfactory mucosa. SYN: pars olfactoria tunicae mucosae [TA], olfactory r. of tunica mucosa of nose, regio olfactoria tunicae mucosae nasi, r. of olfactory mucosa, Schultze membrane.
- olfactory r. of nose [TA] that part of the nasal mucosa having olfactory receptor cells and glands of Bowman. SYN: olfactory membrane.
- parietal r. [TA] the surface r. of the head corresponding to the outlines of the underlying parietal bone. SYN: regio parietalis capitis [TA].
- pectoral r. [TA] the r. of the chest demarcated by the outline of the pectoralis major muscle; includes lateral pectoral, mammillary, and inframammary regions. SEE ALSO: anterior and lateral thoracic regions. SYN: regio pectoralis [TA].
- perineal r. [TA] the regio at the lower end of the trunk, anterior to the sacral r. and posterior to the pubic r. between the thighs; it is divided into the anal triangle posteriorly and the urogenital triangle anteriorly. SYN: regio perinealis [TA].
- posterior r. of arm [TA] the back of arm. SYN: regio antebrachii posterior [TA], regio brachialis posterior, facies brachialis posterior, posterior brachial r., posterior surface of arm.
- posterior cervical r. [TA] the back of neck, including the suboccipital r.. SYN: regio cervicalis posterior [TA], regio colli posterior, nuchal r., posterior neck r., posterior r. of neck, regio nuchalis.
- posterior r. of elbow [TA] the back of the elbow. SYN: regio cubitalis posterior, facies cubitalis posterior, posterior cubital r., posterior surface of elbow.
- posterior r. of forearm [TA] the area between the radial and ulnar borders of the forearm posteriorly. SYN: regio antebrachialis posterior, facies antebrachialis posterior, posterior antebrachial r., posterior surface of forearm.
- posterior hypothalamic r. caudal portions of the hypothalamus located internally in the area of the mamillary body, includes medial, intermediate, and lateral mamillary nuclei and the posterior hypothalamic nuclei. SEE ALSO: posterior hypothalamic area.
- posterior r. of knee [TA] the posterior r. of the knee, including the popliteal fossa. SYN: regio genus posterior [TA], posterior knee r..
- posterior r. of leg [TA] the back of the leg. SYN: regio cruralis posterior [TA], facies cruralis posterior, facies posterior cruris, posterior crural r., posterior surface of leg.
- posterior r. of thigh [TA] the back of the thigh. SYN: regio femoris posterior [TA], facies femoralis posterior, posterior surface of thigh, regio femoralis posterior.
- posterior r. of wrist [TA] the posterior part of the wrist. SYN: regio carpalis posterior [TA], posterior carpal r..
- preoptic r. the most anterior part of the hypothalamus surrounding the anterior or preoptic part of the third ventricle and including the lamina terminalis; containing the lateral and medial preoptic nucleus continuous caudally with, respectively, the lateral and anterior hypothalamic nucleus; rostrally the preoptic r. is continuous with the precommissural septum, laterally with the innominate substance. SYN: area preoptica [TA], preoptic area [TA].
- presumptive r. in experimental embryology, an area of the blastula from which a specific tissue or organ may be expected to develop.
- pretectal r. SYN: pretectal area.
- pubic r. [TA] the lower central r. of the abdomen below the umbilical r. and superior to the mons pubis. SYN: hypogastrium [TA], regio pubica.
- respiratory r. of mucosa of nasal cavity [TA] the area commencing at the vestibule of the nose lined with respiratory mucosa; with the exception of the olfactory mucusa, it includes the entire nasal cavity. SYN: pars respiratoria tunicae mucosae [TA], regio respiratoria tunicae mucosae nasi, r. of respiratory mucosa, respiratory r. of tunica mucosa of nose.
- scaffold-associated regions (SAR) sites in DNA that bind topoisomerase II and other scaffold proteins; found in introns.
- scapular r. [TA] the area of the back corresponding to the outlines of the scapula. SYN: regio scapularis [TA].
- sternocleidomastoid r. [TA] the r. overlying the sternocleidomastoid muscle, including the lesser supraclavicular fossa. SYN: regio sternocleidomastoidea [TA].
- suboccipital r. upper back of neck, inferior to occipital r. of head and above the level of the second cervical vertebra; overlies (or includes, deeply) the suboccipital triangle.
- sural r. [TA] the muscular swelling of the back of the leg below the knee, formed chiefly by the bellies of the gastrocnemius and soleus muscles. SYN: regio suralis [TA].
- temporal r. of head [TA] the surface r. of the head corresponding approximately to the outlines of the temporal bone. SYN: regio temporalis capitis [TA].
- regions of upper limb [TA] the topographic divisions of the upper limb : deltoid, arm, brachial, cubital, antebrachial, carpal, and hand. SYN: regiones membri superioris [TA], regions of superior limb.
- urogenital r. SYN: urogenital triangle.
- variable r. immunoglobulin.
- vertebral r. [TA] the central r. of the back, corresponding to the underlying vertebral column. SYN: regio vertebralis [TA].
- zygomatic r. [TA] the r. of the face outlined by the zygomatic bone; the prominence above the cheek. SYN: regio zygomatica [TA].
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re·gion 'rē-jən n
1) any of the major subdivisions into which the body or one of its parts is divisible <the nine \regions of the abdomen>
2) an indefinite area surrounding a specified body part <a pain in the \region of the heart>
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re·gion (reґjən) a plane area with more or less definite boundaries; for names of specific regions not listed here, see under regio. regional adjMedical dictionary. 2011.