DESCRIBE THE FUNCTIONS OF THE PARTS OF A MAMMALIAN SKIN. (20 MKS)

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Parts and functions.
  • Cornified layer; for protecting the skin; against mechanical damage and bacterial infection
  • Cornified layer; also protects the skin against water loss;
  • Granular layer; cells divide to give rise to cornified layer;
  • Malphighian layer; cells divide to give rise to granular layer;
  • It contains melanin which protects the skin against UV light;
  • Sebaceous gland; -produce oily secretion which is antiseptic; and protects the body against micro-organisms; Sebum makes skin supple; and waterproof. This protects the skin from drying and desiccation;
  • Blood vessels; bring oxygen; and food; to the skin and also remove waste products; from the
  • skin. Blood vessels also control body temperature;
  • Nerve ending; enable mammals to detect changes in the external environment;
  • Sweat glands; produce sweat; and when sweat evaporates, it brings cooling of the body;
  • Sweat also removes waste products from the body;
  • Skin has hair or fur which also maintains body temperature’
  • Subcutaneous fat; in the dermis insulates the body against heat loss or gain; also acts as a store for fats.
20 marks

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