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(il-oo″-mĭ-nā′shŏn) [L. illuminare, to light up] The lighting up of a part for examination or of an object under a microscope.

axial i. Light transmitted along the axis of a microscope. SYN: central i.

central i. Axial i.

dark-field i. The illumination of an object under a microscope in which the central or axial light rays are stopped and the object is illuminated by light rays coming from the sides, which causes the object to appear light against a dark background. This technique is used to observe extremely small objects such as spirochetes or colloid particles.

direct i. The illumination of an object under a microscope by directing light rays upon its upper surface.

fiber i. The transmission of light to an object through fiber-optic cables.

focal i. Concentration of light on an object by a mirror or a system of lenses.

oblique i. Illumination of an object from one side.

transmitted light i. Illumination in which the light is directed through the object. Light may come directly from a light source or be reflected by a mirror.


(il-oo′zhŏn) [L. illusio, jeering, mockery] An inaccurate perception; a misinterpretation of sensory impressions, as opposed to a hallucination, which is a perception formed without an external stimulus. Vague stimuli are conducive to the production of illusions. If an illusion becomes fixed, it is said to be a delusion. SEE: delusion; hallucination. illusional (il-oo′zhŏn-ăl), adj.

optical i. A visual impression that is inaccurately perceived.


(i-loo′sŏ-rē) [L. illusorius, mocking, ironic] Pert. to or causing an illusion; misleading; deceptive.


internal medicine; intramuscular(ly).




inferior mesenteric artery; internal mammary artery.


(ī′mă) [L. imus, lowest] Lowest.


(im′ij) [Fr. image fr. L. imago, copy, likeness] 1. A mental picture representing a real object. 2. A more or less accurate likeness of a thing or person. 3. A picture of an object as produced by a lens or mirror. 4. In radiology, a representation of structures within the body as a result of examination by various physical phenomena, e.g., x-rays, gamma rays, sound, or radio.

body i. 1. The subjective image or picture people have of their physical appearance based on their own observations and the reaction of others. 2. The conscious and unconscious perception of one’s body at any particular time.

direct i. An image produced from radiation without secondary image receptors. ...

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