Controlling temperature

• The skin regulates our body’s temperature.
• Our body must be kept at 37°C to be able to function properly.
• At this temperature enzymes work their best.
• The skin:

  
• When we are hot our hair will lay flat.
• (Hot)To cause this the erector muscle will be relaxed.
• (Hot)The thickness of the insulating air layer will be thin.
• (hot)The heat will be lost through the skins surface.
• When we are cold our hair will stick up.
• (Cold)to cause this the erector muscle will contract.
• (cold)The thickness of the insulating air layer will be thick.
• (cold)the heat will increase.
• On our skin when we are cold to show that our hair is raised we will have goosebumps.
• Vasoconstriction is a response to being cold.
• When vasoconstriction occurs the blood vessels at the skin’s surface will become narrow. This will result in heat loss decreasing.
• During vasoconstriction, blood flow in the skin‘s capillaries will decrease.
• As a result of the blood moving away from the skin surface it helps to keep heat in the body.
• When we are cold our skin will look pale and blue.
• Vasodilation will occur when we are hot.
• During vasodilation, the blood vessels by the skin’s surface will widen(dilate).
• During vasodilation, heat loss will increase.
• During vasodilation, the blood flow in the skin capillaries will increase.
• By blood moving to the skins surface will help to reduce heat as the heat can be lost through radiation from the skin more easily.
• When we are hot the skin will look red.
• Vasoconstriction and Vasodilation:

  
• When we are cold we will shiver.
• Shivering is caused by the muscles contacting uncontrollably.
• When our muscles contract they require energy from respiration which releases heat.
• The heat is used to heat the body up.
• When people are hot they sweat.
• Sweat is produced by the sweat gland.
• The sweat will travel up the sweat duct to get to the skins surface.
• The hole in which let’s sweat out is the sweat pore.
• when sweat is at the skins surface it will be lost through radiation.
• Sweat will take excess heat with it.
• The body will use this mechanism to cool down.
• The type of feedback mechanism that body temperature is controlled is negative feedback.
• A negative feedback mechanism is a mechanism that tries and restores something back to its original state. If the level of something rises, control systems reduce it again. If the levels fall, control systems will raise it again.