| BFEC | benign focal epilepsy of childhood |
|---|---|
| EFL | effective focal length |
| FCD | feces collection device; fibrocystic disease; fibrocystic dysplasia; focal cytoplasmic degradation |
| FD | familial dysautonomia; family doctor; fan douche; fatal dose; fetal danger; fibrin derivative; fibro... |
| FDH | familial dysalbuminemic hyperthyroxinemia; focal dermal hypoplasia; formaldehyde dehydrogenase |
| nuchal plane | <anatomy> The external surface of the squamous part of the occipital bone below the superior nuchal line, giving attachment to the muscles of the back of the neck. (05 Mar 2000) |
|---|---|
| datum plane | An arbitrary plane used as a base from which to make craniometric measurements. (05 Mar 2000) |
| Daubenton's plane | The plane of the foramen magnum. See: Daubenton's angle, Daubenton's line. (05 Mar 2000) |
| supracrestal plane | A horizontal plane passing through the summits of the iliac crests; it usually passes through the fourth lumbar spinous process. Synonym: planum supracristale, supracrestal plane. (05 Mar 2000) |
| supracristal plane | A horizontal plane passing through the summits of the iliac crests; it usually passes through the fourth lumbar spinous process. Synonym: planum supracristale, supracrestal plane. (05 Mar 2000) |
| supraorbitomeatal plane | A plane passing the superior orbital margins and the superior margin of the external acoustic meatuses; it makes an angle of approximately 25 to 30 degrees with the Frankfort plane and is the plane in which routine CT (computed tomography) scans of the brain are made. (05 Mar 2000) |
| suprasternal plane | A horizontal plane passing through the body at the level of the superior margin of the manubrium of the sternum. (05 Mar 2000) |
| infraorbitomeatal plane | A standard craniometric reference plane passing through the right and left porion and the left orbitale; drawn on the profile radiograph or photograph from the superior margin of the acoustic meatus to the orbitale. Synonym: auriculo-infraorbital plane, eye-ear plane, Frankfort horizontal plane, Frankfort plane, infraorbitomeatal plane. (05 Mar 2000) |
| intermediary plane | <microscopy> When in an optical system several successive real image planes of an object are formed, reticles or diaphragms can be inserted at an intermediate plane for superposition on the final image. (05 Aug 1998) |
| intermediate image plane | <microscopy> In a light microscope, the plane into which the objective lens directly focuses the image of the specimen. The plane is usually located a set distance (commonly 10 mm) below the shoulder for the ocular and another fixed distance (generally 160 mm) behind the rear focal plane of the objective lens. The ocular forms a virtual image of the intermediate image for visual observation, or projects a real image for photography and video microscopy. Note: The objective lens, combined with the coverslip of proper thickness, is corrected for projecting the primary image to the specified intermediate image plane only. (05 Aug 1998) |
| interspinal plane | A horizontal plane passing through the anterior superior iliac spines; it marks the boundary between the lateral and umbilical regions superiorly and the inguinal and pubic regions inferiorly. Synonym: planum interspinale, Lanz's line. (05 Mar 2000) |
| intertubercular plane | A horizontal plane passing through the iliac tubercles. Synonym: planum intertuberculare. (05 Mar 2000) |
| occipital plane | The external surface of the occipital bone above the superior nuchal line. Synonym: planum occipitale. (05 Mar 2000) |
| occlusal plane | <dentistry> The imaginary surface on which upper and lower teeth meet. (08 Jan 1998) |
| orbital plane | The orbital surface of the maxilla, lying perpendicular to the orbitomeatal plane at the orbitale. Synonym: planum orbitale. (05 Mar 2000) |