Pancreas and Controlling Blood Glucose

Question 1

What are the main functions of the pancreas? (2)

Answer 1

• Endocrine gland - produce hormones and release them into the blood
• Exocrine gland - produce enzymes and release them via a duct into the duodenum

Question 2

What is the role of the pancreas as an exocrine gland? (2)

Answer 2

• Producing digestive enzymes - proteases, lipases, amylases

- Produce an alkaline fluid (pancreatic juice)

Question 3

What is the role of the pancreas as an endocrine gland? (3)

Answer 3

• Produce insulin
• Produce glucagon
• Both produced in the Islets of Langerhans

Question 4

Compare Alpha and Beta cells in the Islets of Langerhans. (3)

Answer 4

• Alpha cells produce and secrete glucagon while Beta cells produce and secrete insulin
• Alpha cells are larger than Beta cells
• Alpha cells are more numerous than Beta cells

Question 5

What is meant by Glycogenolysis?

Answer 5

Glycogen stored in liver and muscles is broken down into glucose

Question 6

What is meant by Gluconeogenesis?

Answer 6

• Production of glucose from non-carbohydrate sources

e. g. from glycerol (lipids) and amino acids

Question 7

What is meant by Glycogenesis?

Answer 7

Production of glycogen from glucose

Stored in muscles and liver

Question 8

What does insulin do to reduce blood glucose concentration? (5)

Answer 8

• Increases rate of absorption of glucose by cells (mainly skeletal muscle cells)
• Increases respiratory rate of cells - use up glucose
• Increased rate of glycogenesis - converting to glycogen
• Increasing rate of glucose to fat conversion
• Inhibiting release of glucagon from the alpha cells

Question 9

Why is insulin constantly secreted and when does it stop being secreted? (2)

Answer 9

• Is broken down by enzymes in the liver so needs to be constantly released to maintain its effect
• Beta cell detects when glucose is back to normal and inhibit the secretion of insulin

Question 10

How does glucagon raise the blood glucose levels? (3)

Answer 10

• Glycogenolysis - Breaks down glycogen store into glucose
• Reduce amount of glucose absorbed by liver cells
• Increasing Gluconeogenesis - Conversion of amino acids and glycerol into glucose in the liver