<P> For a century, chemists regarded "fats" as only simple lipids made of fatty acids and glycerol (glycerides), but new forms were described later . Theodore Gobley (1847) discovered phospholipids in mammalian brain and hen egg, called by him as "lecithins". Thudichum discovered in human brain some phospholipids (cephalin), glycolipids (cerebroside) and sphingolipids (sphingomyelin). </P> <P> The terms lipoid, lipin, lipide and lipid have been used with varied meanings from author to author . In 1912, Rosenbloom and Gies proposed the substitution of "lipoid" by "lipin". In 1920, Bloor introduced a new classification for "lipoids": simple lipoids (greases and waxes), compound lipoids (phospholipoids and glycolipoids), and the derived lipoids (fatty acids, alcohols, sterols). </P> <P> The word "lipid", which stems etymologically from the Greek lipos (fat), was introduced in 1923 by Gabriel Bertrand . Bertrands included in the concept not only the traditional fats (glycerides), but also the "lipoids", with a complex constitution . </P> <P> In 1947, T.P. Hilditch divided lipids into "simple lipids", with greases and waxes (true waxes, sterols, alcohols), and "complex lipids", with phospholipids and glycolipids . </P>

Where is a lipid found in the human body