Section 5b – Hormonal Control & Communication

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

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

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

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

Blood Sugar Control - summary

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

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

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