arch

arch

Any structure resembling a bent bow or an arch; an arc. In anatomy, any vaulted or archlike structure. See arcus.arcus [NA]; [thru O. Fr. fr. L. arcus, bow]
abdominothoracic a. a bell-shaped line defined by the lower end of the sternum and the costal a.'s on each side, constituting a boundary line between the anterolateral portions of the thoracic and abdominal walls.
alveolar a. of mandible the free margin of the alveolar process of the mandible.arcus alveolaris mandibulae [NA] , limbus alveolaris (1);
alveolar a. of maxilla the free border of the alveolar process of the maxilla.arcus alveolaris maxillae [NA] , limbus alveolaris (2);
anterior a. of atlas an arch that connects the lateral masses of the atlas anteriorly and articulates with the anterior articular facet of the dens of the axis.arcus anterior atlantis [NA];
anterior palatine a. palatoglossal a
a. of the aorta aortic a. (1)
aortic a. 1. the curved portion between the ascending and descending parts of the aorta; it begins as a continuation of the ascending aorta posterior to the sternal angle, runs posteriorly and slightly to the left as it passes over the root of the left lung, and becomes the descending aorta as it reaches and begins to course along the vertebral column; it gives rise to the brachiocephalic trunk, the left common carotid and left subclavian arteries;a. of the aorta; 2. any member of the several pairs of arterial channels encircling the embryonic pharynx in the mesenchyme of the brachial a.'s; there are potentially six pairs, but in mammals the fifth pair is poorly developed or absent. The first and second pairs are functional only in very young embryos; the third pair is involved in the formation of the carotids; the fourth a. on the left is incorporated in the a. of the aorta; the sixth pair forms the proximal part of the pulmonary arteries.arcus aortae [NA];
aortic a.'s a series of arterial channels encircling the embryonic pharynx in the mesenchyme of the branchial a.'s. There are potentially six pairs, but in mammals the fifth pair is poorly developed or absent. The first and second pairs are functional only in very young embryos; the third pair is involved in the formation of the carotids; the fourth a. on the left is incorporated in the a. of the aorta; the sixth pair forms the proximal part of the pulmonary arteries.
arterial a.'s of colon anastomosing branches of the colic arteries that form a.'s in the mesocolon from which the walls of the colon are supplied. See marginal artery of colon.
arterial a.'s of ileum a.'s formed in the mesentery by branches of the superior mesenteric artery from which vessels (vasa recta, under vas) arise to supply the wall of the ileum. See also intestinal arterial arcades, under arcade.
arterial a.'s of jejunum a.'s formed in the mesentery by branches of the superior mesenteric artery from which vessels (vasa recta, under vas) arise to supply the walls of the jejunum. See also intestinal arterial arcades, under arcade.
arterial a. of lower eyelid formed by the medial palpebral artery which communicates with a branch of the lacrimal artery along the tarsal margin.arcus palpebralis inferior [NA];
arterial a. of upper eyelid formed by communicating branches of the medial and lateral palpebral arteries. Often two arches are present, one located near the free border of the tarsal plate, the other along the upper border of the tarsus.arcus palpebralis superior [NA];
axillary a. pectorodorsalis muscle
branchial a.'s typically, 6 a.'s in vertebrates; in the lower vertebrates, they bear gills; in the higher vertebrates, they appear transiently and give rise to specialized structures in the head and neck.pharyngeal a.'s, visceral a.'s;
carpal a.'s two anastomotic arterial twigs running transversely across the wrist: the palmar or anterior lies in front of the carpus, being formed by palmar carpal branches of the radial and ulnar arteries; the dorsal or posterior lies on the dorsal surface of the carpus, being formed by the dorsal carpal branches of the radial and ulnar arteries.
coracoacromial a. a protective a. formed by the smooth inferior aspect of the acromion and the coracoid process of the scapula with the coracoacromial ligament spanning between them. This osseoligamentous structure overlies the head of the humerus, preventing its upward displacement from the glenoid fossa.
cortical a.'s of kidney the portions of renal substance (cortex) intervening between the bases of the pyramids and the capsule of the kidney.
Corti's a. the a. formed by the junction of the heads of Corti's inner and outer pillar cells.
costal a. that portion of the inferior aperture of the thorax formed by the articulated cartilages of the seventh to tenth (false) ribs.arcus costalis [NA] , arcus costarum;
a. of cricoid cartilage the narrow part of the cartilage that encircles the air passage anterior to the lamina.arcus cartilaginis cricoideae [NA];
crural a. inguinal ligament
deep crural a. iliopubic tract
deep palmar (arterial) a. the arterial arch located deep to the long flexor tendons in the hand. It is formed by the terminal part of the radial artery in conjunction with the deep palmar branch of the ulnar artery. The a. gives rise to palmar metacarpal and princeps pollicis arteries.arcus palmaris profundus [NA] , arcus volaris profundus;
deep palmar venous a. the venous arch that accompanies the deep palmar arterial arch; it usually consists of paired venae comitantes.arcus venosus palmaris profundus [NA];
dental a. the curved composite structure of the natural dentition and the residual ridge, or the remains thereof after the loss of some or all of the natural teeth.
dorsal venous a. of foot the arch in the subcutaneous tissue of the dorsum of the foot formed by the dorsal and digital veins; it unites medially with the dorsal vein of the great toe to form the great saphenous vein, and laterally with the dorsal vein of the little toe to form the small saphenous.arcus venosus dorsalis pedis [NA];
double aortic a. congenital malformation of the aorta that splits and has a right and a left a. instead of a single a.
expansion a. an orthodontic appliance that moves the dental structures distally, bucally, or labially, creating increased molar to molar width and arch length.
fallen a.'s a breaking down of the a.'s of the foot, either longitudinal, transverse, or both; the resulting deformity is flat or splay foot, or both.
fallopian a. inguinal ligament
femoral a. inguinal ligament
a.'s of the foot See longitudinal a. of foot, plantar a.
glossopalatine a. palatoglossal a
Gothic a. needle point tracing
Haller's a.'s See lateral arcuate ligament, medial arcuate ligament.
hemal a.'s three or four V-shaped bones located ventral to the bodies of the third to sixth coccygeal vertebrae; they represent intercentra and usually enclose the ventral caudal artery and vein.
hyoid a. the second visceral, or branchial, a; the second postoral a. in the branchial a. series.
iliopectineal a. a thickened band of fused iliac and psoas fascia passing from the posterior aspect of the inguinal ligament anteriorly across the front of the femoral nerve to attach to the iliopectineal eminence of the hip bone posteriorly. The iliopectinal a. thus forms a septum which subdivides the space deep to the inguinal ligament into a lateral muscular lacunae and a medial vascular lacunae. When a psoas minor muscle is present, its tendon of insertion blends with the iliopectineal a.arcus iliopectineus [NA] , iliopectineal ligament, ligamentum iliopectineale;
inferior dental a. the teeth supported by the alveolar part of the mandible, whether the 10 deciduous teeth or the 16 permanent teeth.arcus dentalis inferior [NA] , mandibular dentition;
jugular venous a. a connecting vein between the two anterior jugular veins in the suprasternal space.arcus venosus juguli [NA];
labial a. an orthodontic a. wire that approximates the labial surfaces of the teeth.
Langer's a. axillary arch muscle
lateral longitudinal a. of foot formed by calcaneus, cuboid and two lateral metatarsals; the combined a. is supported normally by ligaments, intrinsic muscles, and the tendons of extrinsic muscles of the foot.arcus pedis longitudinalis pars lateralis;
lateral lumbocostal a. lateral arcuate ligament
lingual a. an orthodontic a. wire that approximates the lingual surfaces of the teeth.
longitudinal a. of foot See medial longitudinal a. of foot, lateral longitudinal a. of foot.arcus pedis longitudinalis, lateral part of longitudinal arch of foot;
malar a. zygomatic a
mandibular a. the first postoral a. in the branchial a. series.mandibular process;
medial longitudinal a. of foot formed by the calcaneus, talus, navicular, three cuneiform bones, and the three medial metatarsals.arcus pedis longitudinalis pars medialis;
medial lumbocostal a. medial arcuate ligament
nasal a. bridge of the nose, the upward arching roof of the piriform aperture formed by the nasal processes of the maxilla of each side and the nasal bones between them. Eyeglasses rest centrally on various portions of this a.
nasal venous a. an a. formed at the root of the nose by the two supratrochlear veins connected by a transverse vein.
neural a. vertebral a
a. of the palate the vaulted roof of the mouth.
palatoglossal a. one of a pair of ridges or folds of mucous membrane passing from the soft palate to the side of the tongue; it encloses the palatoglossus muscle and forms anterior margin of the tonsillar fossa. Also demarcates oral cavity from isthmus of fauces.arcus palatoglossus [NA] , anterior palatine a., anterior pillar of fauces, arcus glossopalatinus, glossopalatine a., glossopalatine fold;
palatopharyngeal a. one of a pair of ridges or folds of mucous membrane which passes downward from the posterior margin of the soft palate to the lateral wall of the pharynx. It encloses the palatopharyngeus muscle and forms the posterior margin of the tonsillar fossa. It also demarcates the isthmus of fauces from oropharynx.arcus palatopharyngeus [NA] , pharyngopalatine a., posterior palatine a., posterior pillar of fauces;
pharyngeal a.'s branchial a.'s
pharyngopalatine a. palatopharyngeal a
plantar a. 1. the arterial arch formed by the lateral plantar artery running across the bases of the metatarsal bones and anastomosing with the dorsal pedis artery; 2. either of two bony a.'s of the foot, longitudinal a. or transverse a. See also medial longitudinal a. of foot, lateral longitudinal a. of foot, transverse a. of foot.arcus plantaris [NA] , plantar arterial a;
plantar arterial a. plantar a
plantar venous a. the arch formed by the plantar digital veins from the toes which accompanies the plantar arterial arch.arcus venosus plantaris [NA];
popliteal a. arcuate popliteal ligament
posterior a. of atlas the posterior arch of the atlas that connects the lateral masses of the atlas posteriorly, forming the posterior wall of the vertebral canal at this level.arcus posterior atlantis [NA];
posterior palatine a. palatopharyngeal a
postoral a.'s the series of branchial a.'s caudal to the mouth; the first is the mandibular, the second is the hyoid; caudal to the hyoid, the a.'s are unnamed, and designated only by their postoral number.
primitive costal a.'s a.'s formed in the thoracic region of the vertebral column in the embryo from the costal processes or costal elements which give rise to the ribs.
pubic a. the arch formed by the symphysis, bodies and inferior rami of the pubic bones. See also subpubic angle.arcus pubis [NA];
ribbon a. a thin, ribbon-shaped, rectangular orthodontic a. wire applied to the dental a.'s so that its widest dimension is parallel to the labial or buccal surfaces of the teeth.
superciliary a. a fullness extending laterally from the glabella on either side, above the orbital margin of the frontal bone.arcus superciliaris [NA] , superciliary ridge;
superficial palmar (arterial) a. the arterial arch in the hand located superficial to the long flexor tendons approximately at the level of a line extrapolated across the palm from the distal side of the outstretched thumb. It is formed principally by the termination of the superficial ulnar artery and is usually completed by a communication with the superficial palmar branch of the radial artery. The a. gives rise to the common palmar digital arteries.arcus palmaris superficialis [NA] , arcus volaris superficialis;
superficial palmar venous a. the venous arch accompanying the superficial palmar arterial arch; it consists usually of paired venae comitantes and is drained by the superficial ulnar and radial veins.arcus venosus palmaris superficialis [NA];
superior dental a. the teeth supported by the alveolar process of the two maxillae, whether the 10 deciduous teeth or the 16 permanent teeth.arcus dentalis superior [NA] , maxillary dentition;
supraorbital a. supraorbital margin
tarsal a. See arterial a. of lower eyelid, arterial a. of upper eyelid.
tendinous a. 1. a white, fibrous band attached to bone and/or muscle, arching over and thus protecting neurovascular elements passing beneath it from injurious compression; 2. a linear thickening of the deep fascia of a muscle which provides attachment for ligaments and/or muscle fibers.arcus tendineus [NA];
tendinous a. of levator ani muscle a thickened portion of the obturator fascia that extends in an arching line from the pubis posteriorly to the ischial spine and gives origin to part of the levator ani muscle.arcus tendineus musculi levatoris ani [NA] , arcus tendineus of obturator fascia;
tendinous a. of pelvic fascia a linear thickening of the superior fascia of the pelvic diaphragm extending posteriorly from the body of the pubis alongside the bladder (and vagina in the female) and giving attachment to the supporting ligaments of the pelvic viscera.arcus tendineus fasciae pelvis [NA];
tendinous a. of soleus muscle a tendinous arch stretching over the popliteal vessels between the tibia and fibula, that gives origin to the central portion of the soleus muscle.arcus tendineus musculi solei [NA];
a. of thoracic duct See thoracic duct.
transverse a. of foot the arch formed by the proximal parts of the metatarsal bones, the three cuneiform bones, and the cuboid.arcus pedis transversalis;
Treitz's a. paraduodenal fold
vertebral a. the posterior projection from the body of a vertebra that encloses the vertebral foramen; it consists of paired pedicles and laminae; the spinous, transverse, and articular processes arise from the arch. In aggregate, the venous a.'s-and the ligamenta flava that unite them-form the posterior wall of the vertebral (spinal) canal.arcus vertebrae [NA] , neural a;
visceral a.'s branchial a.'s
W-a. a fixed maxillary expansion device attached to the lingual part of the molars, with either bilateral or unilateral extension arms.
wire a. a wire conforming to the dental a.; used to restore the normal curve to the denture.
zygomatic a. the arch formed by the temporal process of the zygomatic bone that joins the zygomatic process of the temporal bone.arcus zygomaticus [NA] , cheek bone (2) , malar a., zygoma (2);

 

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