| inorganic compound | A compound in which the atoms or radicals consist of elements other than carbon and are typically held together by electrostatic forces rather than by covalent bonds; often are capable of dissociation into ions in polar solvents (e.g., H2O). Compare: organic compound. (05 Mar 2000) |
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| isocyclic compound | Any compound in which the constituent atoms, or any part of them, form a ring. Used mainly in organic chemistry where: 1) numerous compound's contain rings of carbon atoms (carbocyclic compound's) or carbon atoms plus one or more atoms of other types (heterocyclic compound's), usually nitrogen, oxygen, or sulfur; 2) where the atoms in the ring are all of the same element (homocyclic or isocyclic compound); 3) where the ring is saturated or contains nonconjugated double bonds (alicyclic compound), the compound is similar in properties to the corresponding acyclic compound (e.g., cyclohexane resembles hexane); 4) where the ring contains conjugated double bonds in a closed loop in which there are 4n + 2 (where n is an integer) delocalised π electrons (Huckel's rule) (aromatic compound; e.g., benzene, pyridine), it is more stable than the corresponding saturated ring and exhibits unusual chemical properties characteristic of itself and not of other types of rings or of acyclic compound's. These aromatic compounds have the ability to sustain an induced ring current. Synonym: closed chain compound, ring compound. (05 Mar 2000) |
| open chain compound | An organic compound in which the chain does not form a ring. Synonym: aliphatic compound, open chain compound. (05 Mar 2000) |
| organic compound | <chemistry> A compound containing carbon. (11 Jan 1998) |
| lens, compound | <microscopy> A lens composed of two or more separate pieces of glass or other optical maternal. These component pieces or elements may or may not be cemented together. A common form of compound lens is a two-element objective, one element being a converging lens of crown glass and the other a diverging lens of flint glass. The combination of suitable glasses or other optical materials (plastics, minerals) properly ground and polished reduces aberrations normally present in a single lens. (05 Aug 1998) |
| abdominal cavity | <anatomy> That portion of the body extending from beneath the diaphragm down to the pelvis. It contains all the abdominal organs. (27 Sep 1997) |
| abdominopelvic cavity | Abdominal cavity plus pelvic cavity. (05 Mar 2000) |
| amniotic cavity | The fluid-filled cavity inside the amnion which contains the developing embryo. (05 Mar 2000) |
| anterior wall of tympanic cavity | It contains the carotid canal and the opening of the auditory tube. Synonym: paries caroticus cavi tympani, anterior wall of middle ear, carotid wall of middle ear. (05 Mar 2000) |
| articular cavity | A joint cavity, the potential space bounded by the synovial membrane and articular cartilages of all synovial joints. Normally, the articular cavity contains only sufficient synovial fluid to lubricate the internal surfaces. Synonym: cavitas articularis, cavum articulare. (05 Mar 2000) |
| axillary cavity | <anatomy> The underarm area. (16 Dec 1997) |
| body cavity | The collective visceral cavity of the trunk (thoracic cavity plus abdominopelvic cavity), bounded by the superior thoracic aperture above, the pelvic floor below, and the body walls (parietes) in between. Synonym: celom, celoma, coelom. (05 Mar 2000) |
| buccal cavity | That part of the mouth bounded anteriorly and laterally by the lips and the cheeks, posteriorly and medially by the teeth and/or gums, and above and below by the reflections of the mucosa from the lips and cheeks to the gums. Synonym: vestibulum oris, buccal cavity, vestibule of mouth. (05 Mar 2000) |
| cavity | <anatomy> A hollow place or space or a potential space, within the body or in one of its organs, it may be normal or pathological. Origin: L. Cavitas (18 Nov 1997) |
| cavity, abdominal | The space between the abdominal wall and the spine. (12 Dec 1998) |