medullary ray(redirected from Medullary rays)
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a line emanating from a center, as a more or less distinct portion of radiant energy (light or heat), proceeding in a specific direction.
α-r's high-speed helium nuclei ejected from radioactive substances; they have less penetrating power than beta rays. See also alpha particles.
actinic r's light rays that produce chemical action, especially those beyond the violet end of the spectrum.
alpha r's α-rays.
β-r's (beta r's) electrons ejected from radioactive substances with velocities as high as 98 per cent of the velocity of light; they have more penetrating power than alpha rays but less than gamma rays. See also beta particles.
cosmic r's very penetrating radiations that apparently move through interplanetary space in every direction.
digital ray a digit of the hand or foot and corresponding metacarpal or metatarsal bone, regarded as a continuous unit.
γ-r's (gamma r's) a type of electromagnetic radiation emitted by an atomic nucleus during a nuclear reaction; see also gamma rays.
grenz r's very soft electromagnetic radiation of wavelengths of about 2 angstroms.
infrared r's radiations just beyond the red end of the visible spectrum, having wavelengths of 0.75–1000 μm; see also infrared.
medullary ray a cortical extension of a bundle of tubules from a renal pyramid.
roentgen r's x-rays.
ultraviolet r's radiant energy beyond the violet end of the visible spectrum, of wavelengths 0.39 to 0.18 μm; see also ultraviolet rays.
x-r's see x-rays.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
the center of the renal lobule, which has the shape of a small, steep pyramid, consisting of straight tubular parts; these may be either ascending or descending limbs of the nephronic loop or collecting tubules.
Farlex Partner Medical Dictionary © Farlex 2012
med·ul·lar·y ray(med'ŭ-lar'ē rā) [TA]
The center of the renal lobule, which has the shape of a small, steep pyramid, consisting of straight tubular parts; these may be either ascending or descending limbs of the nephronic loop or collecting tubules.
Synonym(s): Ferrein pyramid.
Synonym(s): Ferrein pyramid.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
medullary raya band of PARENCHYMA cells in plant roots and stems leading out from the centre along a radius and separating the vascular tissues, forming xylem rays and phloem rays in primary and secondary growth. Rays enable the transport of water and other materials across the stem or root. see SECONDARY THICKENING.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
Ferrein,Antoine, French anatomist, 1693-1769.
Ferrein canal - a space between the closed lids and the eyeball through which the tears flow to the punctum lacrimale. Synonym(s): rivus lacrimalis
Ferrein foramen - the opening on the anterior aspect of the petrous part of the temporal bone which leads to the facial canal and gives passage to the greater petrosal nerve. Synonym(s): hiatus of facial canal
Ferrein ligament - the capsular ligament that passes obliquely down and backward across the lateral surface of temporomandibular joint. Synonym(s): lateral temporomandibular ligament
Ferrein pyramid - the center of the renal lobule, which has the shape of a small, steep pyramid, consisting of straight tubular parts. Synonym(s): medullary ray; processus ferreini
Ferrein tube - Synonym(s): convoluted tubule of kidney
Ferrein vasa aberrantia - biliary canaliculi that are not connected with hepatic lobules.
processus ferreini - Synonym(s): Ferrein pyramid
Medical Eponyms © Farlex 2012