cilium

Definitions

  • WordNet 3.6
    • n cilium a hairlike projection from the surface of a cell; provides locomotion in free-swimming unicellular organisms
    • n cilium any of the short curved hairs that grow from the edges of the eyelids
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Webster's Revised Unabridged Dictionary
    • n Cilium See Cilia.
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Century Dictionary and Cyclopedia
    • n cilium In anatomy, one of the hairs which grow from the margin of the eyelids; an eyelash.
    • n cilium One of the minute, generally microscopic, hair-like processes of a cell or other part or organ of the body, or of an entire organism, permanently growing upon and projecting from a free surface, capable of active vibratile or ciliary movement, producing currents in surrounding media, as air or water, and thus serving as organs of ingestion or egestion, prehension, locomotion, etc. In the higher animals cilia are very characteristic of the free surface of various tissues, as mucous membrane, the epithelial cells of which are ciliated. In such cases the cilia have in the individual cells precisely the same action as in the numberless microscopic animals of which they are highly characteristic, as infusorians, radiolarians, polyzoans, rotifers, and the embryonic or larval stages of very many other invertebrates. Cilia are distinguished by their permanency from the various temporary processes which resemble them, such as pseudopodia, and by their minuteness and activity from the similar but usually larger special processes known as flagella, vibracula, etc.; but the distinction is not absolute. The peculiar vibratile action of cilia is termed ciliary motion. See cuts under blastocæsle, Paramecium, and Vorticella.
    • n cilium In botany: In mosses, one of the hair-like processes within the peristome.
    • n cilium One of the microscopic hair-like appendages which are often present upon the reproductive bodies, such as antherozoids and zoospores of cryptogams. They are frequently two in number and vibrate with great rapidity, producing locomotion.
    • n cilium In entomology, a hair set with others; a fringe, like eyelashes, generally on the leg or margins of the wings of insects.
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Etymology

Webster's Revised Unabridged Dictionary
L., eyelid

Usage

In literature:

At this stage many of the spores assume each a flagellate cilium, and so acquire power of more rapid locomotion.
"The North American Slime-Moulds" by Thomas H. (Thomas Huston) MacBride
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In science:

The activity of the dynein molecular motors coupled to the microtubules leads to periodic bending deformations and waves along the cilium.
Mechanical oscillations at the cellular scale
Axonemes are able to generate periodic deformations and to propagate bending waves along the elastic cilium.
Mechanical oscillations at the cellular scale
Finally, the hair bundles of non-mammalian vertebrates contain in addition to many stereocilia a single cilium which contains an axoneme.
Mechanical oscillations at the cellular scale
The physical mechanisms for oscillations generated by molecular motors in a cilium therefore could cover the audible frequency range by using a simple morphological gradient in the cochlea.
Mechanical oscillations at the cellular scale
The most common structure has nine microtubule doublets spaced around the circumference and running along the length of a flagellum or cilium, with two microtubules along the center.
The hydrodynamics of swimming microorganisms
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