(n.) A plane figure bounded by four right lines, of which no two are parallel.
(n.) A bone of the carpus at the base of the first metacarpal, or thumb.
(n.) A region on the ventral side of the brain, either just back of the pons Varolii, or, as in man, covered by the posterior extension of its transverse fibers.
Example Sentences:
(1) The authors describe three patients in whom this complication occurred after Silastic replacements of the carpal scaphoid and trapezium bones.
(2) The wrist motion remaining after simulated arthrodeses was as follows: capitate-hamate: flexion (Flx) 98%, extension (Ext) 92%, ulnar deviation (UD) 96%, radial deviation (RD) 90%; scaphoid-lunate: Flx 97%, Ext 91%, UD 90%, RD 91%; scaphoid-trapezium-trapezoid: Flx 86%, Ext 88%, UD 67%, RD 69%; scaphoid-lunate-triquetrum: Flx 91%, Ext 82%, UD 86%, RD 70%; capitate-lunate: Flx 70%, Ext 59%, UD 89%, RD 79%; capitate-hamate-triquetrum: Flx 88%, Ext 79%, UD 88%, RD 81%; hamate-triquetrum: Flx 90%, Ext 85%, UD 89%, RD 94%; scaphoid-trapezium-trapezoid-capitate: Flx 85%, Ext 77%, UD 64%, RD 57%.
(3) Twenty-five patients who presented with symptoms of disabling pain secondary to arthritis at the base of thumb had 29 arthroplasties with silicone rubber trapezium implants.
(4) Although the design features of the Niebauer implant offer theoretical advantages for stability and fixation, this study does not demonstrate better results compared with other types of silicone trapezium implants.
(5) Operation, consisting of resection of the trapezium and shortening by 1.5 cm of the abductor pollicis longus tendon was performed on 16 thumbs.
(6) If there is localized uptake in the area of the trapezium, additional radiographic studies may be necessary to confirm or exclude this fracture.
(7) The fracture of the trapezium can prevent the normal mobility of the thumb, and therefore an anatomical reduction is desirable.
(8) Osteoarthritic involvement of more than one of the articular surfaces of the trapezium was found in a group of 31 hands.
(9) The area under each sensitivity gradient was determined using the trapezium rule.
(10) The first point of reference is fixed and consists of a line projected through the radial articular surface of the second metacarpal with the trapezium.
(11) Trapezium-scaphoid-trapezoid subluxations and trapezoid-capitate-scaphoid-trapezium subluxations or dislocations are rare.
(12) The present study deals with patients in whom the diagnostic procedures applied in rhizoid arthrosis were considered to reveal scaphoid-trapezium-trapezoid (STT) arthrosis.
(13) We studied 18 patients ranging in age from 16 years to 57 years who presented 8 to 78 months (average, 31.7 months) after silicone arthroplasty (four scaphoid, six lunate, one scapholunate, four finger, two wrist, one trapezium, and one ulnar head for metacarpal hemiarthroplasty).
(14) Fractures of the body of the trapezium are uncommon.
(15) After excision of the trapezium, a strip from the flexor carpi radialis was wound around the main portion of the flexor carpi radialis tendon and the abductor pollicis longus.
(16) The patients treated by resection of the trapezium and tendon interposition were more satisfied and had less pain than those treated by implantation of a Swanson prosthesis.
(17) Having performed 100 anatomical dissections we found that in the first dorsal compartment of the wrist besides other tendons there are one or two tendons belonging to a musculo-tendinous unit, not yet described, inserting in the trapezium and acting almost together with the other units going to the first metacarpal.
(18) Excision of the trapezium gave good results with respect to pain relief, but there was loss of thumb stability and strength.
(19) Relationships between the younger, single members of staff were purest catnip to us; we were always turning love triangles into love trapeziums.
(20) The physio-pathology of fractures of the trapezium was investigated by personal experiments conducted in the laboratory on 26 wrists and showed 3 main mechanisms: a fall on the hand with the wrist extended and radially deviated (Manon) and direct commissural trauma combined with various degrees of shearing described by Monsche.
Ventral
Definition:
(a.) Of or pertaining to that surface of a carpel, petal, etc., which faces toward the center of a flower.
(a.) Of, pertaining to, or situated near, the belly, or ventral side, of an animal or of one of its parts; hemal; abdominal; as, the ventral fin of a fish; the ventral root of a spinal nerve; -- opposed to dorsal.
(a.) Of or pertaining to the lower side or surface of a creeping moss or other low flowerless plant. Opposed to dorsal.
Example Sentences:
(1) The possibility that the ventral nerve photoreceptor cells serve a neurosecretory function in the adult Limulus is discussed.
(2) While the heaviest anterogradely labeled ascending projections were observed to the contralateral ventral posterolateral nucleus of the thalamus, pars oralis (VPLo), efferent projections were also observed to the contralateral ventrolateral thalamic nucleus (VLc) and central lateral (CL) nucleus of the thalamic intralaminar complex, magnocellular (and to a lesser extent parvicellular) red nucleus, nucleus of Darkschewitsch, zona incerta, nucleus of the posterior commissure, lateral intermediate layer and deep layer of the superior colliculus, dorsolateral periaqueductal gray, contralateral nucleus reticularis tegmenti pontis and basilar pontine nuclei (especially dorsal and peduncular), and dorsal (DAO) and medial (MAO) accessory olivary nuclei, ipsilateral lateral (external) cuneate nucleus (LCN) and lateral reticular nucleus (LRN), and to a lesser extent the caudal medial vestibular nucleus (MVN) and caudal nucleus prepositus hypoglossi (NPH), and dorsal medullary raphe.
(3) By 3 d in the chick embryo, the first neurons detected by antibodies to Ng-CAM are located in the ventral neural tube; these precursors of motor neurons emit well-stained fibers to the periphery.
(4) Following injections of HRP into the apex of the heart, the sinoatrial (SA) nodal region and the ventral wall of the right ventricle, we observed that HRP-labeled sympathetic neurons were localized predominantly in the right stellate ganglia, and to a lesser extent, in the right superior and middle cervical ganglia, and left stellate ganglia.
(5) The effects of clozapine on the spontaneous firing rate of noradrenergic (NE, locus coeruleus), dopaminergic (DA, zona compacta, ventral tegmental area) and non-dopaminergic (zona reticulata) neurons was studied in chloral hydrate anesthetized rats.
(6) Differences between parental and nonparental birds in VIP profiles were detected in the ventral portion of the infundibular region.
(7) The dominance of XBMP-4 over activin may account for the ability of injected XBMP-4 RNA to 'ventralize' whole Xenopus embryos.
(8) This column is located ventral and lateral to the dorsolateral division of the trigeminal motor nucleus, and just medial to the descending trigeminal nerve rootlets.
(9) Lumbosacral spine films revealed only minimal degenerative changes, while lumbar myelogram showed L4-L5 and L5-S1 ventral extradural defects.
(10) The ventral root dissection technique was used to obtain contractile and electromyogram (e.m.g.)
(11) The ventral tract ends almost entirely in the anterior lobe with the majority of fibres terminating contralateral to the side of the hemisection.
(12) Descending neurons have opposite structural polarity, arising in the brain and terminating in segmental regions of the fused ventral ganglia.
(13) It was found that within the dorsal part of the well known pressor area there is a narrow strip, 2.5 mm lateral from the mid line, starting ventral to the inferior colliculus and ending in the medulla close to the floor of the IV ventricle, from which vasodilatation in skeletal muscles is selectively obtained.
(14) Injection of the tracer substance wheat germ agglutinin-horseradish peroxidase (WGA-HRP) directly into the basilar pontine nuclei using a ventral surgical approach resulted in the labeling of somata in many areas both rostral and caudal to the basilar pons.
(15) Contact guidance has been suggested to direct NC cells ventrally in the trunk, but this has been subject to doubt (see Newgreen and Erickson, 1986, Int.
(16) These additional projections were interpreted as entering the CN by a ventral route.
(17) Cytochrome oxidase histochemistry revealed patchy patterns of the enzyme activity in transverse sections through the caudal part of the ventral subnucleus of the principal sensory trigeminal nucleus, interpolar spinal trigeminal nucleus, and layer IV of the caudal spinal trigeminal nucleus in the cat.
(18) Zebrin II-negative Purkinje cells are present in a continuous region encompassing the rostromedial part of the valvula, the lobus transitorius, lobe C1 and the ventral part of lobe C2, and in a small, lateral zone of the posterior part of the caudal lobe.
(19) To test whether congenital nemaline myopathy (NM) might have a neurogenic basis, we evaluated the number and frequency distribution of L5 motoneuron cell bodies and their myelinated ventral root (VSR) axons in a typical case.
(20) Fractionation of the supernatant from ventral or dorsal hypothalamic homogenates resulted in a bimodal distribution of IR-TSH.