microvillus

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microvillus

 [mi″kro-vil´us]
a minute process or protrusion from the free surface of a cell, found especially in the proximal convolution of renal tubules and the intestinal epithelium. See illustration.
Microvilli in the intestinal tract. From Applegate, 1992.

mi·cro·vil·lus

, pl.

mi·cro·vil·li

(mī-krō-vil'ŭs, -vil'ī),
One of the minute projections of cell membranes greatly increasing surface area; microvilli form the striated or brush borders of certain cells.

microvillus

/mi·cro·vil·lus/ (-vil´us) a minute process from the free surface of a cell, especially cells of the proximal convolution in renal tubules and of the intestinal epithelium.

mi·cro·vil·lus

, gen. and pl. microvilli (mī'krō-vil'ŭs, -ī)
One of the minute projections of cell membranes greatly increasing surface area; microvilli form the striated or brush borders of certain cells.

microvillus

a minute finger-like process found in numbers projecting from the cell surface where, in epithelium, they form a brush border. Microvilli are found, for example, on the villi lining the small intestine.

microvillus

pl. microvilli; a minute process of protrusion from the free surface of a cell, especially cells of the proximal convolution in renal tubules and of the intestinal epithelium.
References in periodicals archive ?
The lens is produced by microvillar projections from the supporting cells alone and is flush with the cuticular surface and convex internally along the margin of the pigment cup.
q] labeled the microvillar projections where light detection is thought to occur, as well as the cell bodies and axons of these photoreceptors (Fig.
Each cup consists of typical crustacean components, including pigment, tapetum, lens, and rhabdomeric microvillar photoreceptor cells, although the photoreceptor sensory cells are inverted relative to the path of light through the eye, similar to vertebrate camera-type eyes (Elofsson, 2006).
In support of this hypothesis, disruption of microvillar connections between blastomeres is sufficient to lead to polyembryony in sand dollars (Vacquier and Mazia, 1968a), while the same disruption of microvillar connections in regular sea urchins held together tightly by a hyaline layer results in relatively normal development (Vacquier and Mazia, 1968b).
These light-responsive microvillar cells have a motor cilium, so once again the planula can orient its movement relative to a fight source, though in this case the effect is directly on the ciliary beating pattern--no eyes, nerves, or muscles are involved.
Retinula cells 2 and 4 are located opposite each other and have a similar microvillar orientation; and cells 1 and 3 are similarly oriented but with their microvilli orthogonal to those of cells 2 and 4 (Fig.
The apex of these polarized cells breaches the surface of the ciliary band and contains a microvillar array (Fig.
A multilamellar or microvillar structure is not, however, a sufficient indication of a photoreceptive function.
plebs have shown that light adaptation at 0 [degrees]C and an increase in temperature to 10 [degrees]C in the dark cause similar migrations of screening pigment granules in retinular cells, but microvillar damage absent under light adaptation was severe in the dark at 10 [degrees]C (Meyer-Rochow and Tiang, 1979, 1982).
In contrast, the ion-transporting cells are tall, cuboidal to columnar cells (about 10 [micro]m thick), with large numbers of mitochondria interposed among the extensively folded basolateral membrane; the apical surface is elaborated into extensive microvillar plates (Copeland and Fitzjarrell, 1968; Johnson, 1980; Barra et al.
These bacteria were located in the extracellular space between the apical cell membrane and microvillar extensions of the membrane (Fig.
All cilia were readily distinguishable from the microvillar cuticle (Figs.