L41: Liver and Pancreas

Question 1

What type of gland, is the greatest portion of the pancreas?

Answer 1

Exocrine

Question 2

What is an exocrine gland?

Answer 2

A gland that produces and secretes substances onto an epithelial surface by way of a duct

Question 3

What percentage of the pancreas is has an endocrine function?

Answer 3

1%, islets of langerhans

Question 4

What is an endocrine gland?

Answer 4

A gland that secretes their products and hormones, directly into the blood rather than through a duct

Question 5

What hormones does the endocrine portion of the pancreas secrete?

Answer 5

• Insulin;
• Glucagon (liver glycogen > glucose);
• Somatosatin (inhibitory hormone, gastric secretion!).

Question 6

What products does the exocrine portion of the pancreas secrete?

Answer 6

• Digestive enzymes;

- Bicarbonate ions.

Question 7

What part of the functional unit of the pancreas secretes enzymes?

Answer 7

Acinus

Question 8

What part of the functional unit of the pancreas secretes bicarbonate?

Answer 8

Ducts

Question 9

What enzymes does the pancreas release?

Answer 9

• Amylase (polysaccharides, glycosidic 1-4 bond);
• Lipase (lipids);
• Trypsin (activates) chymotrypsin (proteins);
• Nucleases (nucleic acids).

Question 10

What role do bicarbonate secretions have?

Answer 10

Neutralisation of gastric acid

Question 11

Describe the structure of the pancreas.

Answer 11

• Head (with uncinate process);
• Neck;
• Body;
• Tail.

Question 12

What is the dominant cell of islets of langerhans?

Answer 12

β cells, 80%

Question 13

What do β cells in the islets of langerhans secrete?

Answer 13

Insulin

Question 14

What is the role of insulin?

Answer 14

Stimulate glycogenesis (glucose > glycogen in liver);
Stimulate uptake of glucose by tissues.

Question 15

What is cystic fibrosis?

Answer 15

• Genetic condition;
• Effects exocrine secretions from the pancreas;
• Abnormally thick secretions;
• Damage to lungs, liver and pancreas;
• Reduced digestive system - malabsorption.

Question 16

What do α cells in the islets of langerhans secrete?

Answer 16

Glucagon (glycogen > glucose)

Question 17

What do δ cells in the islets of langerhans secrete?

Answer 17

Somatostatin (inhibits gastric secretions)

Question 18

What are the functions of the liver?

Answer 18

• Metabolism of material absorbed from gut;
• Storage of glycogen;
• Release of glucose;
• Proteinsynthesis;
• Inactivation of hormones and drugs (alcohol too);
• Excretion of waste;
• Bile production.

Question 19

Describe the structure of the liver.

Answer 19

4 lobes:

• Left;
• Right;
• Caudate (superior);
• Quadrate (inferior).

Question 20

Which is the largest lobe of the liver?

Answer 20

Right lobe

Question 21

What is the functional unit of the liver?

Answer 21

Heaptocyte

Question 22

What do hepatocytes produce?

Answer 22

Bile

Question 23

What are the constituents of bile?

Answer 23

• Lipid emulsifiers (bile salts);

- Waste products (inc. bile pigments, bilirubin).

Question 24

Where is bile concentrated and stored?

Answer 24

Gall bladder

Question 25

Describe the gross structure of the biliary system

Answer 25

• Right and left hepatic ducts drain each lobe of the liver;
• Join and form the common hepatic duct;
• This then joins with the cystic duct (from gall bladder);
• To form common bile duct.

Question 26

What is the blood supply to the liver?

Answer 26

• Hepatic portal vein, venous blood from G.I. tract etc.;

AND common hepatic artery (coeliac trunk).

Question 27

What drains the blood from the liver?

Answer 27

Inferior vena cava via hepatic veins

Question 28

What are large capillaries, that flow past hepatocytes, called?

Answer 28

Sinusoids

Question 29

What is a portal triad?

Answer 29

A distinctive component of a hepatic lobule that consists of branches of:

• Hepatic portal vein;
• Hepatic artery;
• Bile ducts (canaliculus).

Question 30

What is the common shape of a hepatocyte?

Answer 30

~ hexagonal