| transition temperature | <chemistry> The temperature at which there is a transition in the organisation of, for example: the phospholipids of a membrane where the transition temperature marks the shift from fluid to more crystalline. Usually determined by using an Arrhenius plot of activity against the reciprocal of absolute temperature, the transition temperature being that temperature at which there is an abrupt change in the slope of the plot. In membranes such phase transitions tend to be inhibited by the presence of cholesterol. (18 Nov 1997) |
|---|---|
| equivalent temperature | The temperature of a thermally uniform enclosure in which, under still air conditions, a "sizable" black body loses heat at the same rate as in the nonuniform environment. (05 Mar 2000) |
| eutectic temperature | The temperature at which a eutectic mixture becomes fluid (melts). (05 Mar 2000) |
| fusion temperature | The recorded temperature at which a 20-gauge metal wire will collapse under a 3-ounce load; the recorded temperature at which porcelain becomes glazed. (05 Mar 2000) |
| 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) |
| Barr body | Small dark staining inactivated X chromosome seen in female (XX) cells. According to the Lyon hypothesis, random inactivation occurs. (18 Nov 1997) |