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Related to rhabdom: Rhabdomere, ommatidium, apposition eye


 (răb′dəm, -dŏm′)
A rodlike structure in the center of each ommatidium in the compound eye of an arthropod, composed of microvilli extending from the surrounding retinular cells.

[From Greek rhabdōma, bundle of rods, from Greek rhabdos, rod; see rhabdomancy.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Zoology) any of many similar rodlike structures found in the eyes of insects
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈræb dəm, -dɒm)

any of various small, rod-shaped anatomical structures.
[1875–80; < Late Greek rhábdōma bundle of rods; see rhabdo-, -oma]
rhab•do•mal (ræbˈdoʊ məl, ˈræb də məl) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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Directly below the lens aperture, the photosensitive microvilli of neighboring retinular cells interdigitate, creating a rhabdom that in cross section appears like the spokes of a wheel (Fig.
The teacher can point out how each individual ommatidium guides light through a lens and cone into a channel (the rhabdom), which contains light-sensitive cells.
Though a regular arrangement of rhabdomeric microvilli was not found, we postulate that this area represents a simple closed rhabdom. Furthermore, a small area of irregularly arranged microvilli which are provided by cells similar to those just described was found rather close to the origin of the optic nerve (Figs.
An open rhabdom structure in the ommatidia of Heteroptera is considered a synapomorphy for Heteroptera, in contrast to the fused rhabdoms in Auchenorrhyncha and Coleorrhyncha (Fischer et al.
Of course, there are many additional questions that remain unanswered in spiders, ranging from the evolutionary basis of variation in field of view to the developmental control of rhabdom size and shape.
The distal half of the sensory cavity is filled with a matrix of microvilli from the sensory cell, resembling a rhabdom (Fig.
argus eyes contain two spectral classes, with visual pigment in the cells of the main rhabdom (R1-7) absorbing maximally at 510 nm and pigment in the eighth retinular cells (R8) at 370 nm (Cummins et al., 1984).
The crystalline cone, which is the product of two cells, lies directly below the cornea and is attached to the tip of the rhabdom of the retinula cells.
plebs, which has about 260 ommatidia with the five retinular cells per rhabdom typical of other amphipods (Hallberg et al., 1980).
These limits exist because each photoreceptor unit of a compound eye, termed a rhabdom, is paired with an individual optical system.
For most superposition compound eyes, the tapetum should, ideally, be formed of reflecting pigment enclosing the proximal third of each rhabdom. This has the effect of doubling the path length of light (by reflecting unabsorbed photons back through the target rhabdom) and restricting the bleed of light between adjacent rhabdoms.
Both electrophysiological and behavioral data closely matched the normalized spectral absorptance curve of a rhodopsin with [[lambda].sub.max] = 495 nm, when rhabdom length and photopigment specific absorbance were considered.