| hook | Basal portion of bacterial flagellum, to which is distally attached the flagellin filament. Proximally the hook is attached to the rotating spindle of the motor. In some bacteria (Myxobacteria) the rotation of the hook itself (without an attached flagellum) may directly cause forward gliding movement. (18 Nov 1997) |
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| hook of hamate bone | A hooklike process on the distal and medial part of the palmar surface of the hamate bone. Synonym: hamulus ossis hamati. (05 Mar 2000) |
| hook of spiral lamina | The upper hooklike termination of the bony spiral lamina at the apex of the cochlea. Synonym: hamulus laminae spiralis, hamulus cochleae, hook of spiral lamina. (05 Mar 2000) |
| hook-billed | <zoology> Having a strongly curved bill. Source: Websters Dictionary (01 Mar 1998) |
| hook-shaped cataract | Congenital cataract with hook-like figures between the foetal and embryonic nuclei. (05 Mar 2000) |
| Hooke's law | The stress applied to stretch or compress a body is proportional to the strain, or change in length thus produced, so long as the limit of elasticity of the body is not exceeded. (05 Mar 2000) |
| Hooke, Robert | <person> British experimental physicist, 1635-1703. See: hookean behaviour, Hooke's law. (05 Mar 2000) |
| hookean behaviour | The behaviour of a perfectly elastic body; i.e., the strain is directly proportional to the stress. See: Hooke's law. (05 Mar 2000) |
| hooked bone | The bone on the medial (ulnar) side of the distal row of the carpus; it articulates with the fourth and fifth metacarpal, triquetral, lunate, and capitate. Synonym: os hamatum, hamatum, hooked bone, unciform bone, unciforme, uncinatum. (05 Mar 2000) |
| hooked bundle of Russell | Fastigial efferent fibres that cross with the cerebellum and descend over the lateral surface of the superior cerebellar peduncle; these fibres largely terminate in the vestibular nuclei and the reticular formation of the pons and medulla. Synonym: hooked bundle of Russell, uncinate fasciculus of Russell. (05 Mar 2000) |
| hooked fasciculus | A band of long association fibres reciprocally connecting the frontal and temporal lobes of the cerebrum, running caudally through the white matter of the frontal lobe, sharply curving ventrally under the stem of the sylvian fissure, and then fanning out to the cortex of the anterior half of the superior and middle temporal gyri. Synonym: fasciculus uncinatus, arcuate fasciculus, frontotemporal tract, hooked fasciculus, temporofrontal tract. (05 Mar 2000) |
| hooker | 1. One who, or that which, hooks. 2. A Dutch vessel with two masts. A fishing boat with one mast, used on the coast of Ireland. A sailor's contemptuous term for any antiquated craft. Source: Websters Dictionary (01 Mar 1998) |
| Hooker, Charles | <person> See: Hooker-Forbes test. (05 Mar 2000) |
| Hooker-Forbes test | A test for compounds with progestational activity; such compounds cause hypertrophy of the stromal nuclei of the endometrium in uteri obtained from spayed mice; a sensitive test capable of detecting 0.0002 ug of progesterone. (05 Mar 2000) |
| hooklets | 1. Clawlike, retractile chitinous hooks that encircle or line the rostellum of the scolex of certain taenioid tapeworms for attachment to the intestinal mucosa, with the additional aid of suckers; the hooklets's can be withdrawn and the rostellum inverted when the tapeworm moves. Various arrangements and forms of the hooklets characterise the families of taenioid cestodes. 2. Hooklets's of degenerated scoleces of Echinococcus species in the fluids of the hydatid cyst. 3. The hooklets's of the oncosphere, by which it claws out of its membrane sheath after hatching and penetrates the host gut wall; these hooklets's can later be found in the cercomer of the procercoid or cysticercoid. (05 Mar 2000) |
| calvarial hook | An instrument used in prying off the top of the skull after it has been sawed around, at autopsies and dissections. (05 Mar 2000) |
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| palate hook | An instrument for pulling forward the soft palate in order to facilitate posterior rhinoscopy. (05 Mar 2000) |
| sliding hook | A movable attachment used on an orthodontic wire for the application of elastic traction or headgear force. (05 Mar 2000) |
| squint hook | A surgical instrument used to lift ocular muscles. (05 Mar 2000) |
| tracheotomy hook | Right-angled hook used in holding the trachea steady during tracheotomy. (05 Mar 2000) |