| Heller operation | Oesophagomyotomy at the gastro-oesophageal region. (05 Mar 2000) |
|---|---|
| Heller's plexus | Plexus of small arteries in the wall of the intestine. (05 Mar 2000) |
| Heller, Arnold | <person> German pathologist, 1840-1913. See: Heller's plexus. (05 Mar 2000) |
| Heller, Ernst | <person> German surgeon, 1877-1964. See: Heller operation. (05 Mar 2000) |
| hellgramite | <zoology> The aquatic larva of a large American winged insect (Corydalus cornutus), much used a fish bait by anglers; the dobson. It belongs to the Neuroptera. Source: Websters Dictionary (01 Mar 1998) |
| hellicograph | An instrument for drawing spiral lines on a plane. Origin: Helix + -graph. Source: Websters Dictionary (01 Mar 1998) |
| Hellin's law | Twins occur once in 89 births, triplets once in 892, and quadruplets once in 893. If the frequency of twins in a population is p, the frequency of triplets is p2, and the frequency of quadruplets is p3. (05 Mar 2000) |
| Hellin, Dyonizy | <person> Polish pathologist, 1867-1935. See: Hellin's law. (05 Mar 2000) |
| hellp syndrome | <syndrome> Haemolysis-elevated liver enzymes-low platelet count syndrome. A pre-eclamptic or eclamptic disorder with the findings shown in the clinical description from which the acronym is created. Severe hypertension may be present. Abnormal sgot and sgpt levels also appear. (12 Dec 1998) |
| Helly's fixative | A combination of potassium dichromate, mercuric chloride, formaldehyde, and distilled water, used as a microanatomic fixative for cytoplasmic granules and nuclear staining; has the same disadvantages as Zenker's fixative. (05 Mar 2000) |
| Helly, Konrad | <person> Swiss pathologist, *1875. See: Helly's fixative. (05 Mar 2000) |
| helmet | 1. A defensive covering for the head. See Casque, Headpiece, Morion, Sallet, and Illust. Of Beaver. 2. The representation of a helmet over shields or coats of arms, denoting gradations of rank by modifications of form. 3. A helmet-shaped hat, made of cork, felt, metal, or other suitable material, worn as part of the uniform of soldiers, firemen, etc, also worn in hot countries as a protection from the heat of the sun. 4. That which resembles a helmet in form, position, etc. <chemistry> As: The upper part of a retort. <botany> A naked shield or protuberance on the top or fore part of the head of a bird. Helmet beetle, an African wood shrike of the genus Prionodon, having a large crest. Origin: OF. Helmet, a dim of helme, F. Heaume; of Teutonic origin; cf. G. Helm, akin to AS. & OS. Helm, D. Helm, helmet, Icel. Hjalmr, Sw. Hjelm, Dan. Hielm, Goth. Hilms; and prob. From the root of AS. Helan to hide, to hele; cf. Also Lith. Szalmas, Russ. Shleme, Skr. Carman protection. Cf. Hele, Hell, Helm a helmet. Source: Websters Dictionary (01 Mar 1998) |
| helmet cell | A schistocyte shaped like a military helmet. (05 Mar 2000) |
| Helmholtz energy | Energy equivalent to the internal energy minus the entropy contribution (TS). (05 Mar 2000) |
| Helmholtz theory of accommodation | That the ciliary muscle relaxes for near vision and allows the anterior aspect of the lens to become more convex. (05 Mar 2000) |