Control of blood sugar

Learning IntentionsI can explain homeostasis in the context of controlling blood sugar levels. I can state the hormonal control of blood glucose levels.I can state the importance of having a stable blood glucose level I can state that diabetes is when a person is unable to control their blood glucose levels.

Success CriteriaI can explain the process of homeostasis in the control of blood sugar levels it is varies from the norm.I can describe the hormonal control of glucose using the terms insulin and glucagon, I can also describe where they are produced and the organ they affect. I understand the importance of glucose control and what happens to the body if control is not maintained. I can describe a graph of levels of glucose, insulin and glucagon after a meal.

Food for the cells - Glucose

Cells need a healthy diet of glucose. Not too much…not too little.

Body needs to control level of sugar (glucose) in the blood. This is done by the pancreas.

Where do you get your glucose from daily? What process require glucose to release energy?

Controlling Glucose levelsYour cells also need an exact level of glucose in the blood to use as energy. Glucose is only in the bloodstream when food is eaten so the body employs a homeostatic mechanism to ensure a regular supply of glucose.

Receptors for glucose are in the pancreas (Islets of Langerhans).

Glucose is regulated by 2 hormones (chemicals) from the pancreas called:

Insulin & Glucagon

The effector organ is the liver.

Normal blood glucose levels

Pancreas

Normal blood glucose levels

Blood Liver

Pancreas Blood Liver

Makes insulin.

Pancreas

Normal blood glucose levels

Transports insulin around the body.

Blood

Converts glucose to glycogen and

stores it.

Liver

Makes glucagon.

Pancreas

Transports glucagon around

the body.

Blood

Converts glycogen back into glucose and puts it back into the blood

Liver

If there is too much glucose in the blood receptor cells produce insulin.

Insulin travels to the liver where it activates an enzyme to convert some glucose to glycogen (returns levels to norm).

Glycogen

Insulin

Glucose in the blood

Excess glucose detected by receptor cells in Islets of Langerhans (in pancreas)

If there is not enough glucose in the blood, different cells in the Islets of Langerhans detect the change and release Glucagon.

This hormone also goes to liver but activates a different enzyme that catalyses the breakdown of glycogen to glucose.

Glycogen

Glucagon

Glucose in the blood

Diabetes

• Some people do not produce enough insulin.

• When they eat food, the glucose levels in their blood cannot be reduced.

• This condition is known as DIABETES.

• Diabetics sometimes have to inject insulin into their blood. They have to be careful of their diet.

Time

Glucose Concentration

Meal eaten

Insulin is produced and glucose levels fall to normal again.

Glucose levels rise after a meal.

Normal

Time

Glucose Concentration

Meal eaten

Insulin is not produced so glucose levels stay high

Glucose levels rise after a meal.

Diabetic

The glucose in the blood increases.

Glycogen

Insulin

Glucose in the blood

But there is no insulin to convert it into glycogen.

Glucose concentration rises to dangerous levels.

Adrenaline• In an emergency the body needs extra glucose

quickly for ‘fight or flight’.• The adrenal glands secrete increased levels of the

hormone adrenaline.• Adrenaline inhibits insulin and promotes the

breakdown of glycogen to glucose.