Skin

Skin

Skin

  • The skin is a barrier to the outside world against bacteria etc.
  • The skin is also very sensitive to we can feel things.
  • The skin's main function is temperature control.
  • Below is how the skin is able to change the bodies temperature.

Cooling the body:

  • Blood capillaries widen (vasodilatation) to bring more blood near the surface of the skin so heat can be lost into the surroundings by radiation and convection
  • Sweat is produced which, as it evaporates, has a cooling effect on the body
  • Hairs lie flat which allows warm air to escape faster

Warming the body:

  • Blood capillaries in the skin become more narrow (vasoconstriction) so less heat is lost into the surroundings
  • Sweating decreases so less heat is lost
  • Hairs on body stand up on end to trap air which reduces warm air escaping so rapidly
Human Biology

Blood and Blood Vessels

Blood and Blood Vessels

The contents of blood including red blood cells, white blood cells, platelets and plasma

Human Biology

Diseases caused by smoking

Diseases caused by smoking

Diseases caused by smoking including Emphysema and Bronchitis

Human Biology

Enzymes

Enzymes

Human Biology

Excretion and Osmo-Regulation

Excretion and Osmo-Regulation

Human Biology

Food

Food

Human Biology

Carbohydrates

Carbohydrates