| water hammer | <physics> 1. A vessel partly filled with water, exhausted of air, and hermetically sealed. When reversed or shaken, the water being unimpeded by air, strikes the sides in solid mass with a sound like that of a hammer. 2. A concussion, or blow, made by water in striking, as against the sides of a pipe or vessel containing it. Source: Websters Dictionary (01 Mar 1998) |
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| water-hammer pulse | <radiology> Corrigan's sign: increased pulse at wrist, aortic insufficiency, widened pulse pressure due to increased stroke volume, diastolic regurgitation (12 Dec 1998) |
| hammer | 1. An instrument for driving nails, beating metals, and the like, consisting of a head, usually of steel or iron, fixed crosswise to a handle. "With busy hammers closing rivets up." (Shak) 2. Something which in firm or action resembles the common hammer; as: That part of a clock which strikes upon the bell to indicate the hour. The padded mallet of a piano, which strikes the wires, to produce the tones. <anatomy> That part of a gunlock which strikes the percussion cap, or firing pin; the cock; formerly, however, a piece of steel covering the pan of a flintlock musket and struck by the flint of the cock to ignite the priming. Also, a person of thing that smites or shatters; as, St. Augustine was the hammer of heresies. "He met the stern legionaries [of Rome] who had been the "massive iron hammers" of the whole earth." (J. H. Newman) Atmospheric hammer, a dead-stroke hammer in which the spring is formed by confined air. Drop hammer, Face hammer, etc. See Drop, Face, etc. Hammer fish. See Hammerhead. Hammer hardening, the process of hardening metal by hammering it when cold. <zoology> Hammer shell, any species of Malleus, a genus of marine bivalve shells, allied to the pearl oysters, having the wings narrow and elongated, so as to give them a hammer-shaped outline; called also hammer oyster. To bring to the hammer, to put up at auction. Origin: OE. Hamer, AS. Hamer, hamor; akin to D. Hamer, G. & Dan. Hammer, Sw. Hammare, Icel. Hamarr, hammer, crag, and perh. To Gr. Anvil, Skr. Aman stone. Source: Websters Dictionary (01 Mar 1998) |
| hammer finger | An avulsion, partial or complete, of the long finger extensor from the base of the distal phalanx. Synonym: drop finger, hammer finger, mallet finger. (05 Mar 2000) |
| hammer nose | A manifestation of severe acne rosacea resulting in significant enlargement of the nose and occurring primarily in men. It is caused by hypertrophy of the sebaceous glands and surrounding connective tissue. The nose is reddened and marked with numerous telangiectasias. (12 Dec 1998) |
| hammer toe | <orthopaedics> A deformity of the toe in which the toe is bent upward like a claw. most commonly seen in the second toe, the condition may be congenital or acquired. Ill fitting shoes (too short or too narrow a fit) can result in hammer toe. Mild cases can be treated with splinting or special shoe inserts. Severe cases may require surgery to straighten the toe. (06 Mar 2000) |
| bone within a bone | <radiology> STOP heavy metal, S: sickle cell disease, T: Thorotrast, O: osteopetrosis, P: Paget's disease, heavy metals, hypervitaminosis D (12 Dec 1998) |
| acute reflex bone atrophy | Atrophy of bones, commonly of the carpal or tarsal bones, following a slight injury such as a sprain. See: causalgia, reflex sympathetic dystrophy. Synonym: acute reflex bone atrophy, posttraumatic osteoporosis, Sudeck's syndrome. Origin: L. English sweat (05 Mar 2000) |
| air-bone gap | The difference between the threshold for hearing acuity by bone conduction and by air conduction. (05 Mar 2000) |
| Albrecht's bone | A small bone between the basioccipital and basisphenoid. (05 Mar 2000) |
| allogeneic bone marrow transplant | <haematology, procedure> A bone marrow transplant using marrow collected from a matched healthy donor, usually a brother or sister. The risks associated with the transplant increase with age and 50 years of age is generally regarded as the upper limit. (13 Nov 1997) |
| alveolar bone | That portion of bone in either the maxilla or the mandible which surrounds and supports the teeth. (12 Dec 1998) |
| alveolar bone loss | The resorption of bone in the supporting structures of the maxilla or mandible as a result of periodontal disease. (12 Dec 1998) |
| alveolar supporting bone | alveolar process |
| amyloidosis: bone manifestations | <radiology> Joint pain without radiographic findings, osteoporosis, especially in axial skeleton, lytic lesions that destroy cortex and invade soft tissue, wrist, scaphoid and lunate lesions that may extend into the carpal tunnel, inducing the classic complaints of carpal tunnel syndrome amyloid arthropathy Differential diagnosis: pigmented villonodular synovitis, synovial chondromatosis, rheumatoid arthritis, TB (12 Dec 1998) |