1. Hormones Learning Objective To be able to describe homeostasis.
To be able to identify key hormones and explain their role in homeostasis

2. Success criteria

3. Match hormones to glands

4. What are hormones?
Hormones are chemical messengers produced by an endocrine gland.
They travel to their target organ in the blood.
Their effects are slower than the nervous system. From a few minutes to a few years

5. What is homeostasis? Homeo = body Stasis = keep the same
Homeostasis is the way the body controls its internal environment.

6. Water content Water leaves the body via the lungs when we breathe out.
It leaves via the skin when we sweat.
Excess water leaves via the kidneys in the urine

7. Ion content Ions are charged particles.
They are lost via the skin when we sweat.
Excess ions are lost via the kidneys in the urine
Examples of important ions are sodium, potassium, calcium, chloride and bicarbonate.

8. Temperature
The temperature is maintained to keep enzymes in the cells working at their optimum.
Excess heat is lost via skin redness and sweating.

9. Blood Glucose
This must be maintained to provide the cells with a constant supply of energy

10. after vigorous exercise
Blood glucose levels
Blood glucose rises just after eating, but quickly returns to normal. Where does the sugar go? Why is it not left in the blood?
normal
after meal
after vigorous exercise
blood glucose (mg/100cm3)
140
120
100 80 60 40 20

11. Maintaining a safe blood glucose level

12. Diabetes Diabetes is when the pancreas produces too little insulin.
The blood glucose goes up a lot because glucose is not driven into the cells and stored as glycogen.
Some of this extra glucose is excreted into the urine as a way of getting rid of it.
Mild Diabetes is controlled by diet or tablets.
More severe diabetes is controlled by insulin injections

13. Complete the sentences – insulin
Teacher notes
This completing sentences activity could be used as a plenary or revision exercise on insulin and blood glucose regulation. Students could be asked to write down the missing words in their books and the activity could be concluded by the completion on the IWB.

14. What is diabetes?
Some people are unable to regulate their blood glucose levels because their pancreas doesn’t produce enough insulin. This is called diabetes.
The lack of insulin means that blood glucose levels can rise dangerously high after eating, which can cause cell damage.
Symptoms of diabetes develop quickly and can be severe. Initial symptoms include:
increased thirst, hunger and production of urine
loss of weight, tiredness and nausea.
Later symptoms include vomiting and abdominal pain. If untreated, diabetes can lead to coma and even death.