<p><strong>Noun</strong></p><ul><li>a sterol, C27H46O, that occurs in all animal tissues, especially in the brain, spinal cord, and adipose tissue, functioning chiefly as a protective agent in the skin and myelin sheaths of nerve cells, a detoxifier in the bloodstream, and as a precursor of many steroids</li><li>deposits of cholesterol form in certain pathological conditions, as gallstones and atherosclerotic plaques</li><li>the commercial form of this compound, obtained from the spinal cord of cattle, used chiefly as an emulsifying agent in cosmetics and pharmaceuticals, and in the synthesis of vitamin D</li></ul>