| 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) |
| pneumatic | 1. Relating to air or gas, or to a structure filled with air. 2. Relating to respiration. Origin: G. Pneumatikos (05 Mar 2000) |
| pneumatic antishock garment | An inflatable suit used to apply pressure to the peripheral circulation, thus reducing blood flow and fluid exudation into tissues, to maintain central blood flow in the presence of shock. Synonym: military antishock trousers. (05 Mar 2000) |
| pneumatic bone | A bone that is hollow or contains many air cells, such as the mastoid process of the temporal bone. Synonym: os pneumaticum, hollow bone. (05 Mar 2000) |
| pneumatic larynx | A device that uses air to produce sound to help a laryngectomee talk. (12 Dec 1998) |
| pneumatic retinopexy | A retinal detachment repair in which the retina is held in place by an expandable gas. Synonym: pneumatic retinopexy. (05 Mar 2000) |
| pneumatic space | Any one of the paranasal sinuses. (05 Mar 2000) |
| pneumatic tire injury | Separation of the skin and subcutaneous tissue from the underlying fascia, classically occurring when an extremity is crushed and rolled over by the tire of a vehicle but may be incurred through other mechanisms that produce shear forces; may occur particularly in cases of obesity. (05 Mar 2000) |
| pneumatic tonometer | A recording applanation tonometer operated by compressed gas. (05 Mar 2000) |
| aaa disease | Endemic anaemia of ancient Egypt, ascribed in the Papyrus Ebers to intestinal infestation with ancylostoma; now called ancylostomiasis. (05 Mar 2000) |