| diaphragm pessary | A ring with a covered opening, used as a platform to support uterus, bladder, or rectum, or to prevent conception. (05 Mar 2000) |
|---|---|
| diaphragm sellae | A fold of dura mater extending transversely across the sella turcica and roofing over the hypophyseal fossa; it is perforated in its centre for the passage of the infundibulum. Synonym: diaphragma sellae, diaphragm sellae, tentorium of hypophysis. (05 Mar 2000) |
| inferior fascia of pelvic diaphragm | The fascia that covers the inferior aspect of the levator ani and coccygeus muscles. Synonym: fascia diaphragmatis pelvis inferior, anal fascia. (05 Mar 2000) |
| inferior fascia of urogenital diaphragm | The layer of fascia extending between the ischiopubic rami inferior to the sphincter urethrae and the deep transverse perineal muscles. Synonym: membrana perinei, fascia diaphragmatis urogenitalis inferior, Camper's ligament, ligamentum triangulare, perineal membrane, triangular ligament. (05 Mar 2000) |
| iris diaphragm | <microscopy> A diaphragm with thin metal leaves so arranged that the rotation of an actuating lever varies the diameter. (05 Aug 1998) |
| eventration of the diaphragm | Extreme elevation of a half or part of the diaphragm, which is usually atrophic and abnormally thin. (05 Mar 2000) |
| urogenital diaphragm | A triangular sheet of muscle between the ischiopubic rami; composed of the sphincter urethrae, and the deep transverse perineal muscles. Synonym: diaphragma urogenitale. (05 Mar 2000) |
| left crus of diaphragm | The muscular origin of the diaphragm from the upper two or three lumbar vertebrae that ascends to the left of the aorta to reach the central tendon. Synonym: crus sinistrum diaphragmatis. (05 Mar 2000) |
| lumbar part of diaphragm | The portion of the diaphragm that arises from the upper lumbar vertebrae and from the medial and lateral arcuate ligaments. See: right crus of diaphragm, left crus of diaphragm, lateral arcuate ligament, medial arcuate ligament. Synonym: pars lumbalis diaphragmatis, vertebral part of diaphragm. (05 Mar 2000) |
| auditory field | The space included within the limits of hearing of a definite sound, as of a tuning fork. (05 Mar 2000) |
| bright field illumination | <microscopy> The method of lighting the specimen with a solid cone of rays. Transmitted bright field illumination is performed by a substage condenser. Reflected bright field illumination is performed by a vertical illuminator. Compare: dark field illumination (05 Aug 1998) |
| bright field imaging | <microscopy> An imaging mode in a transmission electron microscopy that uses only unscattered Electrons to form the image. Contrast in such an image is due entirely to mass-thickness variations in amorphous samples, and may include diffraction contrast in crystalline samples. (05 Aug 1998) |
| bright field microscopy | <technique> Optical microscopy, in which absorption to a great extent and diffraction to a minor extent give rise to the image, as opposed to phase contrast or interference methods of microscopy. (18 Nov 1997) |
| Broca's field | The posterior part of the inferior frontal gyrus of the left or dominant hemisphere, corresponding approximately to Brodmann's area 44; Broca identified this region as an essential component of the motor mechanisms governing articulated speech. Synonym: Broca's area, Broca's field, motor speech centre. (05 Mar 2000) |
| cardioid dark field condenser | <microscopy> A condenser designed with two reflecting surfaces, the first, a spherical surface which reflects the rays to a second, cardioid (heart-shaped) surface. The virtue in such an arrangement is that, if the cardioid surface is of true figure, the lens is both achromatic and aplanatic. It has a limiting numerical aperture of about 1.0. Thus objectives of a greater numerical aperture cannot be used successfully with it. A true cardioid figure is the trace of a point on the circumference of a circle rolling around an equal, fixed circle. (05 Aug 1998) |