| valve of oval foramen | A fold projecting into the left atrium from the margin of the foramen ovale in the foetus; when, with beginning inspiration, the blood pressure within the left atrium increases, the valve closes and its edges become adherent to the margin of the foramen ovale, occluding it. Synonym: valvula foraminis ovalis, falx septi, valve of oval foramen. (05 Mar 2000) |
|---|---|
| oval | 1. Of or pertaining to eggs; done in the egg, or inception; as, oval conceptions. 2. Having the figure of an egg; oblong and curvilinear, with one end broader than the other, or with both ends of about the same breadth; in popular usage, elliptical. 3. Broadly elliptical. A body or figure in the shape of an egg, or popularly, of an ellipse. 4. <geometry> Cassinian oval, the locus of a point the product of whose distances from two fixed points is constant; so called from Cassini, who first investigated the curve. Thus, the locus may consist of a single closed line, or of two equal ovals about points A and B. Origin: F. Ovale, fr. L. Ovum egg. Source: Websters Dictionary (01 Mar 1998) |
| oval amputation | Amputation in which the flaps are obained by oval incisions through the skin and muscle, rarely used term for oblique amputation. (05 Mar 2000) |
| oval area of Flechsig | A compact bundle composed of descending branches of posterior root fibres located near the border between the fasciculi gracilis and cuneatus of the cervical and thoracic spinal cord; it corresponds to the septomarginal fasciculus, Hoche's tract, or oval area of Flechsig in the lumbar, and to the triangle of Philippe-Gombault in the sacral spinal segments; like these, it can be demonstrated only in cases of demyelination resulting from dorsal root lesions. Synonym: fasciculus semilunaris, fasciculus interfascicularis, comma bundle of Schultze, comma tract of Schultze, interfascicular fasciculus. (05 Mar 2000) |
| oval corpuscle | One of numerous oval bodies found in the papillae of the skin, especially those of the fingers and toes; they consist of a connective tissue capsule in which the axon fibrils terminate around and between a pile of wedge-shaped epithelioid cells. Synonym: corpusculum tactus, Meissner's corpuscle, oval corpuscle, touch corpuscle. (05 Mar 2000) |
| oval fasciculus | A compact bundle composed of descending branches of posterior root fibres located near the border between the fasciculi gracilis and cuneatus of the cervical and thoracic spinal cord; it corresponds to the septomarginal fasciculus, Hoche's tract, or oval area of Flechsig in the lumbar, and to the triangle of Philippe-Gombault in the sacral spinal segments; like these, it can be demonstrated only in cases of demyelination resulting from dorsal root lesions. Synonym: fasciculus semilunaris, fasciculus interfascicularis, comma bundle of Schultze, comma tract of Schultze, interfascicular fasciculus. (05 Mar 2000) |
| oval window | Fenestra of the vestibule; an oval opening in the medial wall of the middle ear leading into the vestibule. Normally it is covered by the base of the stapes. (12 Dec 1998) |
| transverse oval pelvis | A pelvis in which the transverse diameter is more than 1 cm longer but less than 3 cm longer than the anteroposterior diameter. Synonym: transverse oval pelvis. (05 Mar 2000) |
| longitudinal oval pelvis | A pelvis in which the anteroposterior diameter is longer than the transverse. Synonym: longitudinal oval pelvis. (05 Mar 2000) |
| anterior condyloid foramen | The canal through which the hypoglossal nerve emerges from the skull. Synonym: canalis hypoglossalis, anterior condyloid canal of occipital bone, anterior condyloid foramen. (05 Mar 2000) |
| anterior palatine foramen | An opening in the posterolateral corner of the hard palate opposite the last molar tooth, marking the lower end of the pterygopalatine canal. Synonym: foramen palatinum majus, anterior palatine foramen. (05 Mar 2000) |
| aortic foramen | The opening in the diaphragm bounded by the two crura, the vertebral column, and the median arcuate ligament, through which pass the aorta and thoracic duct. Synonym: hiatus aorticus, aortic foramen, aortic opening. (05 Mar 2000) |
| apical dental foramen | The opening at the apex of the root of a tooth that gives passage to the nerve and blood vessels. Synonym: foramen apicis dentis, apical dental foramen, root foramen. (05 Mar 2000) |
| apical foramen of tooth | The opening at the apex of the root of a tooth that gives passage to the nerve and blood vessels. Synonym: foramen apicis dentis, apical dental foramen, root foramen. (05 Mar 2000) |
| arachnoid foramen | The large midline opening in the posterior inferior part of the roof of the fourth ventricle, connecting the ventricle with the cerebellomedullary cistern. Synonym: apertura mediana ventriculi quarti, arachnoid foramen, Magendie's foramen, median aperture of the fourth ventricle. (05 Mar 2000) |