Ciliary body
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It is the middle part of the vascular tunic and connects the chorioid with the periphery of the iris.
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In meridional section, it is triangular in outline with the base next to the iris. It consists of three parts, ciliary ring, ciliary processes and ciliary muscle.
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The ciliary ring is continuous with the anterior part of the chorioid and presents on its inner surface, numerous fine ridges arranged in a radial manner.
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The ciliary processes are formed by the plating and folding of the lamina propria and the lamina basalis of the chorioid and are received between the corresponding folds of the suspensory ligament of the lens The internal face of the folds is continuous with the lamina basalis there are two layers of epithelial cells that constitute pars ciliaris retinae.
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The ciliary muscles constitute the outer part of the ciliary body and lies between the sclera and ciliary processes.
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It forms a circular band of unstriped muscle. They arise from the inner face of the sclera and ligamentum pectinatum iridis close to the sclero-corneal junction and are inserted to the ciliary processes and ring.
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When the muscles contract, it pulls the ciliary processes forwards, thus slackening the suspensory ligament of the lens and allows the later to become more convex. This is the mechanism of accommodation for near objects.
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Last modified: Monday, 17 October 2011, 6:58 AM