| language zone | A large area of the cerebral cortex on the left side (in right-handed persons) considered by some to embrace all the centres of memories and associations connected with language. (05 Mar 2000) |
|---|---|
| latent zone | That portion of the cerebral cortex, the stimulation of which produces no movement and a lesion of which produces no symptoms; mainly the more anterior areas of the frontal lobes. (05 Mar 2000) |
| frontal zone contraction theory | Model proposed to account for the movement of giant amoebae in which cytoplasmic contraction at the front of the leading pseudopod (fountain zone) pulls viscoelastic cytoplasm forward in the centre of the cell and forms a tube of more rigid cytoplasm immediately below the plasma membrane behind the active region. The peripheral contracted cytoplasm relaxes into a weaker gel at the rear and is pulled forward in its turn. Contrasts with the ectoplasmic tube contraction model. (18 Nov 1997) |
| Lissauer's marginal zone | A longitudinal bundle of thin, unmyelinated and poorly myelinated fibres capping the apex of the posterior horn of the spinal gray matter, composed of posterior root fibres and short association fibres that interconnect neighboring segments of the posterior horn. Synonym: fasciculus dorsolateralis, tractus dorsolateralis, dorsolateral tract, fasciculus marginalis, Lissauer's bundle, Lissauer's column, Lissauer's fasciculus, Lissauer's marginal zone, Lissauer's tract, marginal fasciculus, Spitzka's marginal tract, Spitzka's marginal zone, Waldeyer's tract, Waldeyer's zonal layer. (05 Mar 2000) |
| acromioclavicular joint | The joint formed by the acromion of the scapula and the acromial extremity of the clavicle. (12 Dec 1998) |
| ankle joint | The joint that is formed by the inferior articular and malleolar articular surfaces of the tibia, the malleolar articular surface of the fibula, and the medial malleolar, lateral malleolar, and superior surfaces of the talus. (12 Dec 1998) |
| anterior intraoccipital joint | Cartilaginous union in the newborn between the lateral and the basilar portions of the occipital bone. Synonym: synchondrosis intraoccipitalis anterior, anterior intraoccipital joint. (05 Mar 2000) |
| arthrodial joint | A synovial joint in which the opposing surfaces are nearly planes and in which there is only a slight, gliding motion, as in the intermetacarpal joints. Synonym: articulatio plana, arthrodia, arthrodial articulation, arthrodial joint, gliding joint. (05 Mar 2000) |
| articular disc of acromioclavicular joint | The articular disk of fibrocartilage usually found between the acromial end of the clavicle and the medial border of the acromion. Synonym: discus articularis acromioclavicularis, acromioclavicular disk, Weitbrecht's cartilage. (05 Mar 2000) |
| articular disc of distal radioulnar joint | The disk that holds together the distal ends of the radius and ulna; it is attached by its apex to a depression between the styloid process and distal surface of the head of the ulna, and by its base to the ridge separating the ulnar notch from the carpal surface of the radius. Synonym: discus articularis radioulnaris, radioulnar disk, radioulnar articular disk, triangular cartilage, triangular disk of wrist, triquetrous cartilage. (05 Mar 2000) |
| articular disc of sternoclavicular joint | The fibrocartilaginous disk that subdivides the sternoclavicular joint into two cavities. Synonym: discus articularis sternoclavicularis, sternoclavicular disk, sternoclavicular articular disk. (05 Mar 2000) |
| articular disc of temporomandibular joint | The fibrocartilaginous plate that separates the joint into upper and lower cavities. Synonym: discus articularis temporomandibularis, mandibular disk, temporomandibular articular disk. (05 Mar 2000) |
| atlantoaxial joint | <anatomy> Compound joint between first and second cervical vertebrae, the atlas and axis bones. (20 Jun 2000) |
| atlanto-occipital joint | <anatomy> A condylar synovial joint between the superior articular facets of the atlas and the condyles of the occipital bone. Synonym: articulatio atlanto-occipitalis, atlanto-occipital articulation. (05 Mar 2000) |
| ball-and-socket joint | A multiaxial synovial joint in which a more or less extensive sphere on the head of one bone fits into a rounded cavity in the other bone, as in the hip joint. Synonym: articulatio spheroidea, articulatio cotylica, cotyloid joint, enarthrodial joint, enarthrosis, socket joint, spheroid articulation, spheroid joint. (05 Mar 2000) |