2.8 blood glucose levels and obesity

Question 1

how are the hormones in the pancreas secreted

Answer 1

The pancreas contains receptors which monitor and respond to changes in blood glucose levels by secreting two hormones.

Question 2

Pancreas hormones involved in blood glucose regulation are

Answer 2

insulin
Glucagon

Question 3

When is insulin in the pancreas secreted

Answer 3

secreted in response to high blood glucose levels

Question 4

When is glucagon in the pancreas secreted

Answer 4

secreted in response to low blood glucose levels

Question 5

Describe the role of insulin in negative feedback control of blood glucose levels.

Answer 5

Insulin is secreted by the pancreas in response to high blood glucose levels and it stimulates liver enzymes to convert glucose into glycogen for storage. This removes the excess glucose from the blood and so reduces the blood glucose level back to set point.

Question 6

Describe the role of glucagon in negative feedback control of blood glucose levels.

Answer 6

Glucagon is secreted by the pancreas in response to low blood glucose levels and it stimulates liver enzymes to breakdown glycogen stores into free glucose for release into the bloodstream storage. This increases the blood glucose level back to set point.

Question 7

What does adrenaline affect

Answer 7

Adrenaline (epinephrine) is the third hormone that affects blood glucose levels.

Question 8

Where is adrenaline released from

Answer 8

Adrenaline is released from the adrenal glands (on top of the kidneys) during exercise and the fight or flight response. Adrenaline stimulates the secretion of glucagon and inhibits the secretion of insulin by the pancreas.

Question 9

What does the release of adrenaline result in

Answer 9

This results in an increase in the blood glucose level of the plasma as the liver is stimulated to break down glycogen stores and release glucose into the blood.

Question 10

Type one diabetes

Answer 10

Type 1 diabetes usually occurs in childhood. A person with type 1 diabetes is unable to produce insulin and can be treated with regular doses of insulin.

Question 11

Type two diabetes

Answer 11

Type 2 diabetes or adult onset diabetes typically develops later in life and occurs mainly in overweight individuals. In type 2 diabetes individuals produce insulin but their cells are less sensitive to it. This insulin resistance is linked to a decrease in the number of insulin receptors in the liver leading to a failure to convert glucose to glycogen.

Question 12

What happens to blood levels when you have diabetes

Answer 12

In individuals with both type 1 and type 2 diabetes, blood glucose levels will rise rapidly after a meal and the kidneys are unable to cope resulting in glucose being lost in the urine.

Question 13

urine test for diabetes

Answer 13

Testing urine for the presence of glucose is often used as an initial indicator of diabetes (urine dip stick test).

Question 14

Glucose tolerance test diabetes

Answer 14

The glucose tolerance test is used to diagnose diabetes. This involves measuring the blood glucose concentrations of the individual initially after a period of fasting (8 hours without food) The individual then drinks a glucose solution and changes in their blood glucose concentration are measured for at least the next two hours. The blood glucose concentration of a diabetic usually starts at a higher level than that of a non-diabetic.

Question 15

What happens during the glucose tolerant test

Answer 15

During the test a diabetic’s blood glucose concentration increases to a much higher level than that of a non-diabetic and takes longer to return to its starting concentration.

Question 16

What the name for a chronic complication of diabetes

Answer 16

Vascular disease can be a chronic complication of diabetes

Question 17

What does chronic elevates blood glucose lead too

Answer 17

Chronic elevated blood glucose levels leads to atherosclerosis and blood vessel damage. Chronic elevation of blood glucose levels leads to the endothelium cells taking in more glucose than normal, damaging the blood vessels.

Question 18

What could artherosclerosis lead to

Answer 18

Atherosclerosis may develop leading to cardiovascular disease, stroke or peripheral vascular disease. These can be referred to as symptoms of macrovascular disease.

Question 19

What are mircrovascular disease sympoms and what could they lead too

Answer 19

Microvascular disease symptoms where small blood vessels (capillaries) are damaged by elevated glucose levels may result in haemorrhage of blood vessels in the retina, renal failure or peripheral nerve dysfunction.

Question 20

Define obesity

Answer 20

Obesity is characterised by excess body fat in relation to lean body tissue such as muscle.

Question 21

How is obesity measured

Answer 21

Body mass index (BMI) is commonly used to measure obesity, where a BMI value greater than 30 is used to indicate obesity.

BMI= Body mass (kg)/ (height m2)

BMI can wrongly classify muscular individuals as obese so care must be taken in the use of BMI values.

Question 22

State the potential impact of obesity on health.

Answer 22

Obesity may impair health as it is a major risk factor for development of cardiovascular disease and type 2 diabetes.

Question 23

Explain the role of diet and exercise in reducing obesity and CVD.

Answer 23

Obesity is linked to high fat diets and a decrease in physical activity.
The energy intake in the diet should limit fats and free sugars as fats have a high calorific value per gram and free sugars require no metabolic energy to be expended in their digestion and so both result in an increase in the storage of body fat.

Question 24

Exercise increases energy expenditure and preserves lean tissue. Exercise can help to reduce risk factors for CVD by :

Answer 24

keeping weight under control,
· minimising stress,
· reducing hypertension and
· improving HDL blood lipid profiles

Question 25

What is the liver and what does it do

Answer 25

The liver is the effector organ which responds to the hormonal signals and decreases / increases the blood glucose level through the action of enzymes to build up / break down stores of glycogen in the liver.