Blood Glucose Noadswood Science, 2016

Blood Glucose To identify how blood glucose is controlled Thursday, May 31, 2018 Blood Glucose To identify how blood glucose is controlled

Precise Learning Blood glucose concentration is monitored and controlled by the pancreas. If the blood glucose concentration is too high, the pancreas produces the hormone insulin that causes glucose to move from the blood into the cells. In liver and muscle cells excess glucose is converted to glycogen for storage. Students should be able to explain how insulin controls blood glucose (sugar) levels in the body. Type 1 diabetes is a disorder in which the pancreas fails to produce sufficient insulin. It is characterised by uncontrolled high blood glucose levels and is normally treated with insulin injections. In Type 2 diabetes the body cells no longer respond to insulin produced by the pancreas. A carbohydrate controlled diet and an exercise regime are common treatments. Obesity is a risk factor for Type 2 diabetes. Students should be able to compare Type 1 and Type 2 diabetes and explain how they can be treated. Students should be able to extract information and interpret data from graphs that show the effect of insulin in blood glucose levels in both people with diabetes and people without diabetes. If the blood glucose concentration is too low, the pancreas produces the hormone glucagon that causes glycogen to be converted into glucose and released into the blood (higher tier only) Students should be able to explain how glucagon interacts with insulin in a negative feedback cycle to control blood glucose (sugar) levels in the body (higher tier only)

Blood Sugar Levels Blood sugar levels are controlled to provide cells with a constant supply of energy Blood sugar level is controlled by the release and storage of glucose controlled by insulin

Insulin Insulin is a hormone which regulates the amount of sugar in the blood – it converts glucose into glycogen (which can be stored in the liver) Insulin is produced in the Islets of Langerhans within the pancreas

Insulin Insulin controls blood sugar levels: - Eating carbohydrates puts a large amount of glucose into the blood Normal metabolism of cells removes glucose from the blood Vigorous exercise removes much more glucose from the blood It is vital to control the level of blood glucose – the bodies mechanism for adding or removing glucose is via insulin

Insulin & Pancreas The pancreas monitors and controls the glucose concentration within the blood The pancreas produced insulin (a hormone) which causes glucose to move from the blood into the cells – lowering the blood [glucose] if it becomes too high Blood [glucose] can become too high after a meal rich in carbohydrates (sweets; potatoes; bread; rice; pasta etc…)

Blood [Glucose] Too High – Insulin Added

Blood [Glucose] Too High – Insulin Added

Blood [Glucose] Too Low – Insulin Not Added When blood sugar is too low another hormone glucagon is released (instead of insulin) Glucagon causes the liver to release glucose into the blood Higher Tier

Blood [Glucose] Too Low – Insulin Not Added Higher Tier

Diabetes Diabetes is a disease in which the pancreas does not produce enough insulin (type 1) or the effect of the insulin produced is resisted by the body (type 2) Diabetes results in the individual having blood [glucose] rise to a level which can kill Diabetes can be controlled via two means: - Avoiding particular foods Insulin injections

Diabetes – Food Avoiding particular foods rich in carbohydrates (which turn to glucose when digested) can prevent problems It can also be helpful to take exercise after eating carbohydrates – trying to use up the extra glucose via physical activities (although this is not that practical)!

Diabetes – Injections Injecting insulin into the blood before meals causes the liver to remove the glucose from the blood as soon as it enters from the gut when the food is being digested This stops the level of glucose in the blood from getting too high (this is extremely effective)

Type 1 Diabetes Type 1 diabetes is a condition where the pancreas produces little or no insulin – it can be controlled via: - Insulin therapy – injecting insulin into the blood Limiting food intake – foods rich in simple carbohydrates are limited Exercise – regular exercise helps lower the blood glucose levels

Type 2 Diabetes Type 2 diabetes is a condition where a person becomes resistant to their own insulin Limiting food intake – foods rich in simple carbohydrates are limited Exercise – regular exercise helps lower the blood glucose levels

Dangers Of Diabetes Glucose is essential for the body – why is excess glucose a danger for people with diabetes? The ability of the kidneys to absorb glucose is also exceeded, so the excess is excreted in urine However if this glucose is then used up the body will not have enough glucose, which can result in convulsions /coma Regular insulin injections and a careful diet can control the condition

Blood Glucose Levels Changes in a person’s blood glucose level over time can be shown graphically – explain what is shown… The person without diabetes has a glucose spike after drinking but then it falls away The diabetic has glucose levels that rise and remain high (significantly higher)

Banting & Best Frederick Banting and Charles Best made an extract from the pancreas in 1921 The extract had anti-diabetic properties, and they tested it successfully on diabetic dogs The first tests in humans were carried out in 1922, and were a success too – some patients who were in a diabetic coma even recovered The extract contained the hormone insulin…

Banting & Best Data Read the passage about Banting and Best, and as a group (per table) answer the questions

Practice Questions Where is insulin produced In a study a hormone was injected into a patient and their blood glucose levels monitored. What hormone was injected and what would happen to the blood glucose level if the other main hormone that affects blood glucose levels was injected instead

Answers Where is insulin produced – pancreas What hormone was injected and what would happen to the blood glucose level if the other main hormone that affects blood glucose levels was injected instead – glucagon was injected as there was a glucose rise. If insulin was injected there would have been a glucose fall