To know how the body regulates its temperature. What is your bodies normal temperature? What happens if you are too hot? What happens if you are too cold?

To know how the body regulates its temperature. Success criteria- State the normal internal body temperature and why this must be maintained. Label the parts of the skin. Describe how the body maintains a constant temperature. Explain why thermoregulation is so important. Construct negative feed back loops (H).

To know how the body regulates its temperature. Humans live in a variety of temperatures. Like all mammals, humans are endotherms (warm blooded). Human body temperature must remain around 37⁰C. -37⁰C= If the rate of enzyme controlled reactions in your cells falls too low, you don’t make enough energy & cells start to die. +37⁰C= Denatures enzymes so can no longer catalyze reactions in cells. Bodies try to maintain 37 degrees as this is the optimum conditions for enzymes.

To know how the body regulates its temperature. State the normal internal body temperature and why this must be maintained. Normal internal body temperature is… If our bodies get too hot… If our bodies get too cold… Keywords: enzymes catalysts denatured optimum slowed reactions

To know how the body regulates its temperature. Function of skin Lets take a closer look at the skin....... Protects us from infection . 2. Keeps our body at the right temperature. 3. Covered in receptors so we can feel things.

To know how the body regulates its temperature. Label the parts of the skin. Hair Erector muscle Sweat gland Blood vessels Temperature receptor Epidermis Fat layer Learners will put the labels in the correct place then write 1 function carried out by the

To know how the body regulates its temperature. On a hot day the skin… 1. Vasodilation of Blood vessels. Capillaries get wider so a Larger amount of blood can flow near the skin surface. Heat is lost to the environment. 2. Evaporation of sweat Sweat is produced from the sweat glands. Sweat evaporates from the skin. 3. Hairs and hair erector muscles are relaxed. 4. No shivering

To know how the body regulates its temperature. On a cold day… 1. Vasoconstriction of Blood vessels. Capillaries get smaller so a smaller amount of blood can flow near the skin surface. Heat is kept near to the body. 2. No sweat is produced. 3. Body starts to shiver to produce heat for the body. 4. Hairs and hair erector muscles stand on end to trap a layer of air.

To know how the body regulates its temperature.

To know how the body regulates its temperature.

To know how the body regulates its temperature. The hypothalamus receives nerve impulses from heat and cold thermoreceptors in the skin. There are also receptors in the hypothalamus- called central thermoreceptors. These detect changes in blood temperature.

To know how the body regulates its temperature. In own words on mini whiteboards Skin in cold conditions Skin in hot conditions

Normal body temperature To know how the body regulates its temperature. Normal body temperature is restored Normal body temperature

Normal body temperature To know how the body regulates its temperature. Vasodilation Hairs lie flat Body sweats No shivering Normal body temperature is restored Vasoconstriction Hairs stand on end Body doesn’t sweat Shivering occurs Normal body temperature The hypothalamus detects a rise in temperature Body temperature falls The hypothalamus detects a fall in temperature Body temperature rises

To know how the body regulates its temperature. http://www.youtube.com/watch?v=NJEBfl_LKno Animal thermoregulation http://www.youtube.com/watch?v=TSUCdLkI474 Thermoregulation

To know how the body regulates its temperature. Could be done… Cotton wool Dry towelling cloth To know how the body regulates its temperature. Set up the equipment as shown opposite. Fill the conical flask with hot water from the kettle. Record the temperature and start your stop clock. Record the temperature every minute for 10 minutes. Record your data in a suitable table. Time (mins) Temperature (°C) Dry Flask Wet Flask (START) 1 Repeat with a wet towelling cloth.

To know how the body regulates its temperature. Success criteria- State the normal internal body temperature and why this must be maintained. Label the parts of the skin. Describe how the body maintains a constant temperature. Explain why thermoregulation is so important. Construct negative feed back loops (H). Why is thermoregulation so important? Why might wearing antiperspirant be a bad thing? What advice would you give to Bear Grylls for his next adventure in the desert? Effective participants

To know how the body regulates its temperature. Most people use antiperspirants to stop themselves sweating, but sweating is good. It is one of the ways that your skin keeps the bodies internal temperature constant. Not much air circulates under your armpits, so the sweat doesn’t evaporate easily anyway. They do stop you smelling though!

To know how the body regulates its temperature. You are a medic in charge of Bear Grylls next adventure in the desert. You must explain to him all the changes that will happen in his body and any steps he should follow to stay healthy. (6 marks) Learners should discuss both as temperature fluctuates http://www.youtube.com/watch?v=KeyHvX5rTpo 8.38

To know how the body regulates its temperature. Negative feedback All homeostatic mechanisms use negative feedback to maintain a constant value (called the set point). Negative feedback means that whenever a change occurs in a system, this automatically causes a corrective mechanism to start, which reverses the original change and brings the system back towards the set point (i.e. ‘normal’).

Recap of negative feed back loop. Insulin produced by the pancreas causes glucose to change to glycogen Stored in the liver and muscles Glucose rises (eat food) Higher Normal blood glucose level (80-120 mg/100cm3 blood) Normal blood glucose level (80-120 mg/100cm3 blood) Glucagon released and glycogen converted back to glucose Glucose falls (exercise)

TOO HOT! TOO COLD! What the body does 1) 2) 3) Detected by 1) 2) Normal temperature What is this? Normal temperature What is this? Students to make their own for What the body does 1) 2) 3) 4) TOO COLD! Detected by 1) 2)

vasodilation vasoconstriction