1. B1 Smart Teach Foundation Session 4

2. Homeostasis Homeostasis is the regulation of conditions in the body such as temperature, water and glucose levels.

3. Temperature How does the body cool down when hot? - Sweat (heat lost when water evaporates). - Hairs lie flat (no hair trapped near the skin). How does the body heat up when cold? -Hairs stand up on end to trap air near the skin. -Shivering. Which part of the body controls human body temperature? - Brain Why is it important that the body temperature does not rise above 40°C? - body temperature should be at 37°C (1) - enzymes work best at optimum temperature (37 °C) (1) - higher temperatures will denature the enzymes / enzymes won’t function / won’t work (1) - (therefore) chemical reactions will stop / decrease (1)

4. Blood Glucose and Diabetes 1.How can blood glucose levels increase? - Eating - Glucagon causes glycogen to be converted into glucose. 2.How can blood glucose levels go down? - Exercise - Insulins causes blood glucose to be stored as glycogen. Diabetes is a disease where the concentration of glucose in the blood is not controlled properly by the body.

5. Basic Knowledge – Blood Glucose 1.What organs are involved regulating blood glucose levels? 2.What hormones are involves in regulating blood glucose levels? 3.Which hormone increases blood glucose? 4.Which hormone decreases blood glucose levels? 5.Which organ releases the hormones need to regulate blood glucose levels? 6.Where is glucose stored? 7.What is the name given to the disease in which the body cannot regulate blood glucose levels?

6. Type 1 Diabetes -Caused when pancreas does not produce insulin. -Not caused by diet. -Can be controlled through diet and injecting insulin after meals.

7. Type 2 Diabetes -Often caused by poor diet and being over weight (eating too much sugar). -Become resistant to insulin (insulin does not work). -Can be controlled/prevented through diet.

8. Exam Questions 1. Explain how the glucose content of the blood can be decreased by insulin (2 marks). -Glucose converted into glycogen. -Stored in liver.

9. The graph shows the percentage of the population with Type 2 diabetes between 1993 and 2000. 1.Describe the overall trend shown in the graph (1). 2.Calculate the change in the percentage of the population with Type 2 diabetes between 1993 and 2000 (2).

11. BMI

12. BMI and Type 2 Diabetes A high BMI (being obese) can cause type 2 diabetes. Too much sugar in diet/not enough exercise.

13. Exam Question 1.Suggest why people with a high BMI may develop Type 2 diabetes (2). - eat poor diet / too much sugar in diet (1) - little exercise (1) - become insulin resistant (1) 2.Describe how people with type 1 diabetes control their blood glucose levels (1). - injecting insulin. 3.Explain how people with type 2 diabetes control their blood glucose levels (2). - less sugar in diet - more exercise - to reduce blood sugar levels

14. Pathogens and Disease A pathogen is a microbe (germ) that causes harm. Two main types of pathogen: 1. Bacteria 2. Virus

15. Pathogens and Disease Pathogens are spread in different ways. Examples: Influenza – virus spread in air. Cholera – bacteria spread in water. Malaria – parasite spread by mosquitos.

16. Fighting Back The body has: 1.Chemical defences (tears and stomach acid). 2.Physical barriers (skin and mucus). We can prevent the spread of pathogens by: 1.Washing hands. 2.Using antiseptics.