Integument(redirected from integumentum)
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Related to integumentum: keratin
the part of the ovary on seed plants that encloses the nucellus (the central part of the ovary). The ovaries of a number of plants have one integument, while others, particularly in the monocotyledonous plants, have two. After fertilization the integument turns into a seed coat.
in animals, including man, the tissues that cover the body and perform protective, tactile, metabolic (including gas exchange), and excretory functions. The integument sometimes performs the function of feeding, associated with the complete reduction of the intestine in tapeworms, acanthocepha-lans, and Pogonophora. Thermoregulation is sometimes a function of the integument.
In most invertebrates the integument consists of cutaneous epithelium, or epidermis, which is of ectodermal origin. It includes a mesodermal connective-tissue layer, or derma, in such invertebrates as nemertines and cephalopod mollusks and in vertebrates, including man. Derivatives of the integument are cutaneous glands, cuticles, the chitinous armor of arthropods, the shells of mollusks, scales, feathers, hair, claws, and nails.