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.

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.
References in periodicals archive ?
Microvillar enzyme assays in amniotic fluid and fetal tissues at different stages of development.
Metabolism of aspartame by human and pig intestinal microvillar peptidases.
tetraceros, the unpigmented ocellus sensory cavity is filled with whorled lamellae and a small microvillar matrix at the distal pore encircling a filamentous mass (Fig.
The mechanism of action of the [delta]-endotoxins involves binding to receptors on the microvillar membranes of the midgut, with a major portion of this interaction becoming irreversible.
Scanning electron microscopy revealed striking changes in the plasma membrane, the microvillar system, intercellular junctions and the sinusoidal endothelium.
coli strains classed as enterohemorragic (e.g., serogroup O157:H7), enteroinvasive (029:NM), or enterotoxigenic (C1845), which showed microvillar destruction (effacement), erythrocyte agglutination, and actin rearrangements or depolymerization (27,49).
Here, anti-[G[alpha].sub.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.