How is the mammalian skin adapted to its functions?

K.C.S.E Biology Q & A - MODEL 2004PP1QN18

How is the mammalian skin adapted to its functions?

answers

• ​The skin is made of epidermis and dermis. The epidermis  is made up of three layers. The outermost  layer is known as cornified layer; made  up of dead cells that protect against mechanical damage/ desiccation/ microbes; the granular layer; is made up of living cells that give rise to the cornified layer, the malpighian layer; contain actively dividing cells that rise to new epidermal cells, that contain melanin that protects the skin  against ultra violet rays.
• The dermis has several components has  sweat glands’ sudondic glands that  produce sweat; sweat  evaporates carrying it with latent  of vaporization) thus reducing the body temperature; under cold  conditions little/ no.
• Sweat is produced thus heat is conserved; the sweat contains water/ sodium chloride/ uric acid/ urea; the skin is excretory organ.
• Has hair, the hair stands erect to trap air when temperature is low to reduce heat loss/ lies  flat to allow heat loss when the temperature is high.
• Has nerve endings, which are sensitive to stimuli/ such as heat/ cold/ pain/ pressure/ touch
• Has subcutaneous  fats/ adipose tissue, that insulate the body against heat loss.
• Has arteriole; that vasodilate when temperature are high to lose heat by radiation/ convection ( see converse)
• Has sebaceous gland; which secrete sebum, an antiseptic/ water repellant/ that prevent drying/ cracking  of  skin/ skin supple
• acc blood vessels/ capillaries for arterioles to supply food/ nutrients/ oxygen/ remove excretory products.