Transcript Chapter 36: Human skin (the integumentary system)

Chapter 36: Human skin (the
integumentary system)
Leaving Certificate Biology
Higher Level
Human skin
Functions of the skin
• Protection – acts as a barrier preventing entry of
pathogens
• Excretion – excretes water, salts and a very small amount
of urea
• Temperature regulation – goose bumps, hairs stand on
end and vasoconstriction occur when cold; sweat
produced, vasodilation, hairs lie flat when hot
• Fat storage – adipose tissue just below the skin stores fat
and acts as an insulator
• Sense organ – sense organs such as temperature and pain
receptors send signals to the brain when stimulated
• Production of vitamin D – sunlight action on the fatty
tissue within the skin causes the production of vitamin D,
which is needed to absorb calcium from the diet