| ball valve | Any of a variety of prosthetic cardiac valve's comprised of a ball within a retaining cage affixed to the orifice; when appropriately sized, used in aortic, mitral, or tricuspid position. (05 Mar 2000) |
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| ball valve action | The intermittent blockage of a tube or outlet of a cavity by some object or material that permits passage in one direction but not in the other. (05 Mar 2000) |
| ball variance | Swelling and changes in shape and consistency of the ball in a ball-valve prosthesis, especially in one replacing the aortic valve. (05 Mar 2000) |
| Ball's operation | Division of the sensory nerve trunks supplying the anus, for relief of pruritus ani. (05 Mar 2000) |
| Ball, Sir Charles | <person> Irish surgeon, 1851-1916. See: Ball's operation. (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) |
| ball-valve thrombus | Ball thrombus intermittently occluding the mitral or tricuspid orifice. (05 Mar 2000) |
| ballad | A popular kind of narrative poem, adapted for recitation or singing; as, the ballad of Chevy Chase; especially, a sentimental or romantic poem in short stanzas. Origin: OE. Balade, OF. Balade, F. Ballade, fr. Pr. Ballada a dancing song, fr. Ballare to dance; cf. It. Ballata. See Ball, and Ballet. Source: Websters Dictionary (01 Mar 1998) |
| Ballance's sign | <clinical sign> The presence of a dull percussion note in both flanks, constant on the left side but shifting with change of position on the right, said to indicate ruptured spleen; the dullness is due to the presence of blood, fluid on the right side but coagulated on the left. (05 Mar 2000) |
| Ballance, Sir Charles | <person> English surgeon, 1856-1936. See: Ballance's sign, Koerte-Ballance operation. (05 Mar 2000) |
| ballast | 1. To steady, as a vessel, by putting heavy substances in the hold. 2. To fill in, as the bed of a railroad, with gravel, stone, etc, in order to make it firm and solid. 3. To keep steady; to steady, morally. "'T is charity must ballast the heart." (Hammond) Origin: Ballasted; Ballasting. Source: Websters Dictionary (01 Mar 1998) |
| ballerina-foot pattern | A vigorous posteromedial contraction of the left ventricle coupled with convexity anteriorly sometimes resulting from poor contraction of the opposing anterior wall; it is the most frequent dyssynergy observed in the prolapsed mitral valve leaflet syndrome (even with a normal anterior wall) and produces a configuration of angiographic dye in the right anterior oblique projection resembling a ballerina's foot; sometimes called dancer's foot malformation. (05 Mar 2000) |
| balling gun | Balling iron An instrument used for administering boluses or capsules to animals. (05 Mar 2000) |
| ballism | A type of involuntary movement affecting the proximal limb musculature, manifested as jerking, flinging movements of the extremity; caused by a lesion of or near the contralateral subthalamic nucleus. Usually only one side of the body is involved, resulting in hemiballismus. Synonym: ballism. Origin: G. Ballismos, a jumping about (05 Mar 2000) |
| ballismus | A type of involuntary movement affecting the proximal limb musculature, manifested as jerking, flinging movements of the extremity; caused by a lesion of or near the contralateral subthalamic nucleus. Usually only one side of the body is involved, resulting in hemiballismus. Synonym: ballism. Origin: G. Ballismos, a jumping about (05 Mar 2000) |