Section 5b – Hormonal Control & Communication

1. Section 5b – Hormonal Control & Communication

2. Internal Communication • We have already seen that internal communication can involve the nervous system • This involves information being passed along nerves/neurones • In addition, signals can also be passed in the bloodstream • The chemicals involved are called hormones

3. Learning Outcomes • Understand the role that hormones play in the human body • Investigate some examples of important human hormones • What the endocrine system consists of, and some of the important sites of hormone production and their targets

4. Endocrine System • Involves the production and transport of hormones • Hormones act as chemical messengers • - produced by glands around the body • They travel through the bloodstream to get to their target tissues • Target tissues have cells with receptors • These receptors are very specific • – they will only join with certain hormones • Target cells will then respond to the hormone

5. Controlling blood glucose • The human body needs to closely control glucose levels in the body • This is controlled by 2 hormones: • 1) Insulin • Produced by cells in the pancreas • Normally produced if blood sugar levels are high • Insulin will help remove excess glucose from the blood • Excess glucose is then stored in the liver as glycogen • 2) Glucagon • Produced by different cells in the pancreas • Produced when blood sugar levels are low • Helps break down glycogen stores in the liver into glucose • This then helps to raise blood glucose levels Glucose Glycogen

6. Blood Sugar Control - summary

7. Diabetes Mellitus • A condition where blood glucose levels cannot be controlled by the body • It is an example of a failed communication pathway • There are two types of diabetes: • Type 1 • – when insulin producing cells are damaged or don’t work • Type 2 • – when insulin is being produced, but not used properly by cells in the body • High sugar levels can cause cells to lose water by osmosis • High blood glucose levels can lead to many symptoms and complications

8. Symptoms of diabetes mellitus • Initially • - frequent thirst, • - frequent urinating, • - fatigue • -weight loss • If left untreated, can lead to: • - heart disease • - kidney failure • - loss of vision

9. Your task • You are required to do a piece of research on the condition diabetes mellitus. • Your research should cover the following areas: • - details of the two types of diabetes – causes/symptoms etc. • - explain the existing available treatments for diabetes • - outline some new treatments / on-going research into treating diabetes