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to confine a beam of x-rays to a region of interest using a collimator or cone (3); colloq., to focus one's attention or activities.
cone down(kōn down)
1. To narrow a beam of x-rays to a region of interest using a collimator or cone (3).
2. Colloquialism, to delimit one's attention or activities.
1. a solid figure or body having a circular base and tapering to a point, especially one of the conelike structures of the retina, which, with the retinal rods, form the light-sensitive elements of the retina. The cones make possible the perception of color.
2. in radiology, a conical or open-ended cylindrical structure used as an aid in producing high detail x-rays.
3. surgical cone.
cone cells (1)
the commonest, if not the sole, photoreceptors in the central area of the retina, where the function of acute vision is located. See also cone (1) above.
in radiology, to restrict the x-ray beam. See also collimation.
cone dysplasia (1)
progressive dysplasia of retinal cones in Alaskan malamute dogs; causes impaired day vision from an early age. The rods are normal.
a cone-shaped device used over the face in administration of ether for anesthesia.
cone of light
the triangular reflection of light seen on the tympanic membrane.
the area of compression exerted by a mass in the brain, as in transtentorial herniation.
see cone (1) above.