4.5.3.2 Control of Blood Glucose Concentration

Question 1

What is blood glucose concentration monitored and controlled by?

Answer 1

the pancreas

Question 2

What happens if blood glucose concentration is too high?

Answer 2

• if blood 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

Question 3

What happens if blood glucose concentration is too low?

Answer 3

• if 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

Question 4

How does insulin help control blood glucose levels?

Answer 4

• Insulin helps control blood glucose levels by signalling to the liver, muscle and fat cells to take in glucose from the blood
• Insulin therefore helps cells to take in glucose to be used for energy
• If the body has sufficient energy, insulin signals the liver to take up glucose and store it as glycogen

Question 5

How does glucagon interact with insulin in a negative feedback cycle to control blood glucose levels in the body?

Answer 5

• Glucagon and insulin interact as part of a negative feedback cycle to control blood glucose (sugar) levels in the body:
  
  • Insulin is produced when blood glucose rises and stimulates liver and muscle cells to convert excess glucose into glycogen to be stored – this reduces the blood glucose level
  • Glucagon is produced when blood glucose falls too low and stimulates liver and muscle cells to convert stored glycogen into glucose to be released into the bloodstream – this increases the blood glucose level

Question 6

Difference between glucose, glycogen and glucagon:

Answer 6

• Glycogen is a stored form of glucose (sugar)
• Glucagon is a hormone that triggers liver glycogen to convert back into glucose and to enter your bloodstream so that your body can use it for energy

Question 7

Type 1 diabetes:

Answer 7

• disorder in which the pancreas fails to produce sufficient insulin
• so body cells unable to take up glucose
• glucose excreted in urine
• lots of urine produced
• body uses fats and proteins for respiration
• person loses weight and feels tired
• if uncontrolled, kidney failure and death will occur
• characterised by uncontrolled high blood glucose levels

Question 8

Causes of type 1 diabetes:

Answer 8

• The body has destroyed the cells that produce Insulin
• This is called an autoimmune condition
• The person’s immune system has attacked the pancreas
• Pancreas’s failure to produce insulin causes type 1 diabetes

Question 9

How is type 1 diabetes treated?

Answer 9

normally treated with insulin injections - help control blood sugar levels

Question 10

What is type 2 diabetes?

Answer 10

body cells no longer respond and lose sensitivity to insulin produced by the pancreas

Question 11

What is a risk factor for type 2 diabetes?

Answer 11

obesity - insulin receptors on liver cells hidden so body cells don’t respond to insulin

Question 12

Why do diabetics have high blood sugar levels?

Answer 12

• high blood sugar levels for diabetes due to insulin produced not being used properly
• means that glucose does not move from the blood to cells and is not converted and stored as glycogen

Question 13

Treatment for type 2 diabetes:

Answer 13

• a carbohydrate controlled diet and an exercise regime are common treatments
• sugary foods should be avoided

Question 14

Type 2 untreated diabetes blood sugar level graph description:

Answer 14

consistently higher blood sugar level

Question 15

Type 2 treated diabetes blood sugar level graph description

Answer 15

significantly lower blood sugar level than treated

Question 16

Non-diabetic blood sugar level graph description:

Answer 16

lowest blood sugar level

Question 17

Why is there more urine produced in diabetes?

Answer 17

• the level of sugar in the blood is abnormally high
• not all of the sugar can be reabsorbed and some of this excess glucose from the blood ends up in the urine where it draws more water

Question 18

Pros of injecting animal insulin:

Answer 18

keeps alive

Question 19

Cons of injecting animal insulin:

Answer 19

• against beliefs
• infection

Question 20

Pros of insulin injection:

Answer 20

• Cheap
• Readily available – now made by bacteria
• No ethical issues

Question 21

Cons of insulin injection:

Answer 21

• Inconvenient
• Painful
• Hard to judge
• Embarrassing?

Question 22

Pros of insulin pump:

Answer 22

• Good control
• Not obtrusive
• Gives more freedom

Question 23

Cons of insulin pump:

Answer 23

• Expensive
• Can limit activity

Question 24

Pros of pancreas transplant:

Answer 24

Total freedom from treatment

Question 25

Cons of pancreas transplant:

Answer 25

• Availability of donor
• Rejection
• Immunosuppressants

Question 26

Pros of changing diet:

Answer 26

effective with type 2 diabetes

Question 27

Cons of changing diet:

Answer 27

not very effective

Question 28

Why and how may a transplanted pancreas be rejected?

Answer 28

• immune system may attack it
• white blood cells in immune system produce antibodies
• which attack the antigens on the transplanted pancreas