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