cytoskeleton

The cytoskeleton is a dynamic three-dimensional filamentous structure within the cytoplasm of eukaryotic cells. It is constructed of microfilaments, intermediate filaments, and microtubules that provide for structural support and movement. image - cytoskeleton : image_cytoskeleton : diagram - mechanism of ciliary motility .

Microfilaments are 3-6 nm in diameter, and are composed mostly of the contractile protein actin – the most abundant cellular protein. Microfilaments are responsible for the cellular movements of gliding, contraction, and cytokinesis. The association of micofilaments of actin with the protein myosin is central to muscle contraction. image_filamentous actin microtubules nuclei : image_filamentous actin & microtubules : image_microtubules nuclei endothelial tc : image_filamentous actin microtubules nuclei fibroblast mouse : image_tubulin microtubules.

Intermediate filaments are about 10 nm diameter and provide tensile strength for the cell connect adjacent cells through desmosomes (macula adherens). diagram . desmosome : tem_desmosome : diagram . tight junction : diagram . gap junction :

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