| MORD | magnetic optical rotatory dispersion |
|---|---|
| OCR | oculocardiac reflex; oculocerebrorenal [syndrome]; optical character recognition |
| OD | Doctor of Optometry; obtained absorbance; occipital dysplasia; occupational dermatitis; occupational... |
| ODU | optical density unit |
| OES | oral esophageal stethoscope; optical emission spectroscopy |
| optical transfer function | <microscopy> The relationship between the image produced by an optical instrument and the amplitude and phase of a periodic specimen, measured at various spatial frequencies. The optical transfer function curve, which shows how well contrast is maintained for finer specimen details, is a complex function, of which the real term gives the ratio of amplitudes, and the imaginary term the phase relationships. When the brightness of the periodic specimen varies as a sine wave, the modulus or absolute value of the optical transfer function becomes the modulation transfer function, when the brightness varies as a square wave, the modulation transfer function is known as a contrast transfer function. Acronym: OTF (26 Mar 1998) |
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| optical tubelength | <microscopy> The distance from the second principal focal plane of the objective to the front focal plane of the ocular. This distance is about 180 mm for high-power objectives, less for those of low power. (05 Aug 1998) |
| electron optical axis | <physics> The path of an electron through an electron optical system along which it suffers no deflection due to lens fields. This axis does not necessarily coincide with the mechanical axis of the system. (05 Aug 1998) |
| electron optical system | <apparatus> A combination of parts capable of producing and controlling a beam of electrons to produce an image of an object. (05 Aug 1998) |
| tubelength optical | <microscopy> This distance is measured from the upper focal plane of the objective to the image formed by the objective alone upon removal of the eyepiece. A light microscope so arranged that the specimen, usually a solid-liquid colloid or suspension, is illuminated by a strong pencil of light at right angles to the microscope axis. The visibility is limited by the intensity of the light source. A laser can be used as the source. It is used to detect the presence of light-ultramicroscopic particles within the range of about 0.005,um to 0.2 ~m. Not to be confused with an electron microscope. (05 Aug 1998) |
| acetone body | <biochemistry> Any of the three compounds created by acetyl coenzyme A (acetoacetate, hydroxybutyrate, and acetone) which are water-soluble cellular fuels normally exported by the liver. They can build up in the blood and body tissues because of starvation, untreated diabetes mellitus, or other disorders that interfere with carbohydrate metabolism. The body rids itself of ketones mainly through urine, but it rids itself of acetone through the lungs, which gives the breath a characteristic fruity odour. If ketones build up in the body long enough, they cause serious illness and coma (see ketoacidosis.) (09 Oct 1997) |
| acute inclusion body encephalitis | The most common acute encephalitis, caused by HSV-1; affects persons of any age; preferentially involves the inferomedial portions of the temporal lobe and the orbital portions of the frontal lobes; pathologically, severe haemorrhagic necrosis is present along with, in the acute stages, intranuclear eosinophilic inclusion bodies in the neurons and glial cells. Synonym: acute inclusion body encephalitis, herpes encephalitis. (05 Mar 2000) |
| adrenal body | See adrenal gland. (12 Dec 1998) |
| alveolar body | That portion of bone in either the maxilla or the mandible which surrounds and supports the teeth. (12 Dec 1998) |
| amygdaloid body | Almond-shaped group of basal nuclei anterior to the inferior horn of the lateral ventricle of the brain, within the temporal lobe. The amygdala is part of the limbic system. (12 Dec 1998) |
| amylogenic body | A plant plastid involved in the synthesis and storage of starch. Found in many cell types, but particularly storage tissues. Characteristically has starch grains in the plastid stroma. (18 Nov 1997) |
| anococcygeal body | <anatomy> A musculofibrous band that passes between the anus and the coccyx. Synonym: ligamentum anococcygeum, anococcygeal body, raphe anococcygea, Symington's anococcygeal body. (05 Mar 2000) |
| anterior quadrigeminal body | The paired, larger, rounded anterior eminence of the laminae of mesencephalic tectum; major afferent connections of the superficial layers are the retina and striate cortex; input to deep layers of the colliculus are polymodal. Its efferent connections are with the lower brainstem and spinal cord (tectobulbar tract and tectospinal tract) and with the pulvinar and other cell groups in the caudal part of the thalamus; participates in extrageniculate visual pathway. Synonym: colliculus superior, anterior quadrigeminal body, corpus quadrigeminum anterius. (05 Mar 2000) |
| aortic body tumour | Aortic body, carotid body, chemoreceptor, or glomus jugulare tumour; nonchromaffin paraganglioma; receptoma; a relatively rare, usually benign neoplasm originating in the chemoreceptor tissue of the carotid body, glomus jugulare, and aortic bodies; consisting histologically of rounded or ovoid hyperchromatic cells that tend to be grouped in an alveolus-like pattern within a scant to moderate amount of fibrous stroma and a few large thin-walled vascular channels. Compare: paraganglioma. Synonym: aortic body tumour, carotid body tumour, chemoreceptor tumour, glomus jugulare tumour, nonchromaffin paraganglioma. Origin: chemo-+ G. Dektes, receiver, fr. Dechomai, to receive, + -oma, tumour (05 Mar 2000) |
| asteroid body | An eosinophilic inclusion resembling a star with delicate radiating lines, occurring in a vacuolated area of cytoplasm of a multinucleated giant cell; especially frequent in sarcoidosis, but occurs also in other granulomas, a structure that is characteristic of sporotrichosis when found in the skin or secondary lesions of this mycosis; in tissue, it surrounds the 3-to 5-um in diameter ovoid yeast of Sporothrix schenkii. (05 Mar 2000) |