| ZR | zona reticularis |
|---|---|
| AAR | active avoidance reaction; acute articular rheumatism; antigen-antiglobulin reaction |
| APR | abdominoperineal resection; absolute proximal reabsorption; acute phase reaction or reactant; amebic... |
| CFR | case-fatality ratio; citrovorum-factor rescue; Code of Federal Regulations; complement-fixation reac... |
| CRT | cadaveric renal transplant; cardiac resuscitation team; cathode-ray tube; certified; Certified Recor... |
| zona pectinata | The outer two-thirds of the basilar membrane of the cochlear duct. Synonym: zona pectinata. (05 Mar 2000) |
|---|---|
| zona pellucida | <cell biology, gynaecology> A translucent, elastic, noncellular layer surrounding the ovum of many mammals. (11 May 1997) |
| zona perforata | The perforations along the tympanic lip of the spiral lamina giving passage to the cochlear nerves. Synonym: habenulae perforata, zona perforata. (05 Mar 2000) |
| zona pupillaris | The central region of the anterior surface of the iris located between the collarette and the pupillary margin. Synonym: zona pupillaris. (05 Mar 2000) |
| zona radiata | The thickened cell membrane of the ovum in forms, such as certain amphibia, in which it appears radially striated under the light microscope; with the electron microscope the striations can be seen to be microvilli. Synonym: membrana striata, striated membrane, zona radiata. (05 Mar 2000) |
| zona reticularis | The inner zone of the adrenal cortex. This zone consists of an anastomosing network of cells which resemble those of the zona fasciculata except for the fact that they contain less lipid. The mitochondria are elongated and contain a mixture of tubular and flattened cristae. (12 Dec 1998) |
| zona serpiginosa | <virology> A reactivation of the same Herpes virus that is responsible for chicken pox. This results in a painful blistery red rash that is confined to one side of the body. The zoster rash affects one nerve distribution or dermatome. Facial rash can lead to optic nerve involvement with resultant blindness. Synonym: shingles. (06 Mar 1998) |
| zona striata | The thickened cell membrane of the ovum in forms, such as certain amphibia, in which it appears radially striated under the light microscope; with the electron microscope the striations can be seen to be microvilli. Synonym: membrana striata, striated membrane, zona radiata. (05 Mar 2000) |
| zona tecta | The inner third of the basilar membrane of the cochlear duct extending from the tympanic lip of the osseous spiral lamina to the outer pillar cell of the spiral organ (of Corti). Synonym: zona arcuata, zona tecta. (05 Mar 2000) |
| zona vasculosa | An area in the external acoustic meatus where a number of minute blood vessels enter from the mastoid bone. Synonym: spongy spot, zona vasculosa. (05 Mar 2000) |
| accelerated reaction | A response occurring in a shorter time than expected; the cutaneous manifestations occurring during the period between the second and tenth day following smallpox vaccination; because it is intermediate between a primary reaction and an immediate reaction, it is regarded as evidence of some degree of resistance. Synonym: vaccinoid reaction. (05 Mar 2000) |
| acid reaction | Any test by which an acid reaction is recognised such as the change of blue litmus paper to red, an excess of hydrogen ions over hydroxide ions in aqueous solution indicated by a pH value less than 7 (at 22캜). Compare: dissociation constant of water. (05 Mar 2000) |
| acute-phase reaction | <immunology, rheumatology> Refers to the changes in synthesis of certain proteins within the serum during an inflammatory response, which provides rapid protection for the host against microorganisms via non-specific defense mechanisms. It consists of fever, an increase in inflammatory humoral factors, and an increased synthesis by hepatocytes of a number of proteins or glycoproteins usually found in the plasma; the reaction is mediated by endogenous pyrogens, the hypothalamus, adrenal hormones, and other factors. (12 Jul 2000) |
| acute situational reaction | An acute emotional reaction related to extreme environmental stress. Synonym: acute situational reaction. (05 Mar 2000) |
| acute stress reaction | A sudden bout of anxiety that is often accompanied by the features of hyperventilation (tingling around mouth and in fingertips, rapid breathing, faintness or fainting). (27 Sep 1997) |