Pancreas

Question 1

What level does the pancreas lie horizontally

Answer 1

L1

Question 2

Is the pancreas intra or retroperitoneal

Answer 2

Retroperitoneal

Question 3

What is the pancreas composed of

Answer 3

Head
Neck
Body
Tail

Question 4

Where on the pancreas does the shape of the duodenum sit

Answer 4

Head

Question 5

What does the pancreas form

Answer 5

Part of the posterior wall of the lesser sac

Question 6

Where does the splenic artery lie to the pancreas

Answer 6

Runs towards the spleen embedded in the upper border of the pancreas

Question 7

Where does the splenic vein lie to the pancreas

Answer 7

Posterior

Question 8

What are the main functions of the pancreas

Answer 8

Endocrine and exocrine functions

Synthesises and secretes insulin and glucagon

Pancreatic juices that contain digestive enzymes

Question 9

Where do the bile duct and main pancreatic duct merge

Answer 9

Hepatopancreatic ampulla

Question 10

Where does the hepatopancreatic ampulla open into

Answer 10

Second part of the duodenum at the major duodenal papilla

Question 11

What is the main blood supply to the pancreas

Answer 11

Coeliac trunk
Superior mesenteric artery

Question 12

Where does the splenic artery supply the pancreas

Answer 12

Major branch from coeliac trunk

Runs along upper border of pancreas

Gives ride to pancreatic arteries

Question 13

Describe the gastroduodenal artery and the pancreas

Answer 13

From coeliac trunk

Gives rise to superior pancreaticoduodenal arteries

Question 14

What does the superior mesenteric artery give rise to

Answer 14

Inferior pancreaticoduodenal arteries

Question 15

What is the innervation of the pancreas

Answer 15

Parasympathetic

Sympathetic

Question 16

What is the parasympathetic innervation of the pancreas

Answer 16

Vagus nerve

Question 17

What is the sympathetic innervation of the pancreas

Answer 17

Greater and lesser splanchnic nerves

Question 18

What are the exocrine secretions of the pancreas

Answer 18

Aqueous bicarbonate secretion

Enzyme secretion

Question 19

Describe aqueous bicarbonate secretion by the pancreas

Answer 19

Epithelial cells in PD produce HCO3- and H2O

Bicarbonate secretion protects duodenal mucosa by neutralising stomach acid

Buffers duodenal contents to optimise pH for enzyme digestion

Resting phase maintains low flow - predominantly Na+ and Cl- ions

Question 20

How much bicarbonate is secreted by the pancreas a day

Answer 20

1L/24 hours

Question 21

Describe enzyme proteases by the pancreas

Answer 21

Majority occurs in the small intestine

Stored as proenzymes

Protein digestion

Question 22

What are the pancreatic proteases

Answer 22

Trypsin

Chymotrypsin

Question 23

What is trypsinogen activated by

Answer 23

Enterokinase

Question 24

What does trypsin activate

Answer 24

Chymotrypsinogen

Additional trypsinogen

Question 25

Describe enzyme lipases in the pancreas

Answer 25

Hydrolyse triglycerides to monoglycerides and free fatty acids Bile salts aid

Question 26

What is fat digestion dependant upon

Answer 26

Pancreatic and hepatic secretions

Question 27

What is orlistat

Answer 27

Pancreatic lipase inhibitor

Question 28

Describe enzyme amylase in the pancreas

Answer 28

Hydrolyses start to maltose and maltotriose and limit dextrin Major source of amylase

Question 29

What are the stages in which there is pancreatic enzyme secretion

Answer 29

Cephalic stage - vagal innervation and gastrin - low level stimulus in anticipation of a meal Intestinal stage - secretin - cholecystokinin - gastrin

Question 30

What is the role of cholecystokinin on pancreatic enzyme release

Answer 30

Pancreatic enzyme and HCO3- secretion Gallbladder contraction Inhibition of gastric acid secretion Delay gastric emptying

Question 31

What is the stimulus for cholecystokinin

Answer 31

HCl Proteins Fats entering duodenum

Question 32

What is the role of secretin in pancreatic enzymes

Answer 32

Pancreatic water and bicarb secretion - carrying enzymes

Question 33

What do gastrin and CCK do

Answer 33

Stimulate enzyme secretion Neutralise gastric acid entering small intestine

Question 34

How long is the pancreas

Answer 34

12-15cm

Question 35

What is the pathway of secretions

Answer 35

Pass into smaller ducts, then 2 larger ducts

Question 36

What is the formation of the pancreas

Answer 36

Formed by small clusters of glandular epithelial cells 98-99% of cells are clusters = acini

Question 37

What cells are exocrine activities performed by

Answer 37

Acinar cells

Question 38

What cells are endocrine activities performed by

Answer 38

Islet cells

Question 39

Describe the exocrine activity of the pancreas

Answer 39

Manufacture and secrete fluid and digestive enzymes (pancreatic juice) which is released into the gut

Question 40

Describe endocrine activity of the pancreas

Answer 40

Manufacture and release several peptide hormones into the portal vein

Question 41

What is the site of insulin and glucagon secretion in the endocrine pancreas

Answer 41

Islet of Langerhans

Question 42

What % of the total volume do the islets of langerhan make up

Answer 42

2-3%

Question 43

What are the cells in the islets of langerhans which have important functions

Answer 43

Beta cell Alpha cell Delta cell Paracrine 'crosstalk' between alpha and beta cells e.g. local insulin releases inhibits glucagon

Question 44

What do beta cells secrete

Answer 44

Insulin

Question 45

What do alpha cells secrete

Answer 45

Glucagon

Question 46

What do delta cells secrete

Answer 46

Somatostatin

Question 47

What are the peptides secreted by the islets of Langerhans

Answer 47

Insulin Glucagon

Question 48

What is the role of insulin

Answer 48

Reduces glucose output by liver, increases storage of glucose, fatty acids, amino acids

Question 49

What is the role of glucagon

Answer 49

Mobilises glucose, fatty acids and amino acids from stores

Question 50

What role does somatostatin play in insulin and glucagon secretion

Answer 50

Inhibitor

Question 51

Describe the role of insluin

Answer 51

Supresses hepatic glucose output - decrease glycogenolysis and gluconeogenesis Increases glucose uptake to insulin sensitive tissue - muscle and fat Supresses - lipolysis - breakdown of muscle (ketogenesis)

Question 52

Describe the role of glucagon

Answer 52

Increases hepatic glucose output - increases glycogenolysis and gluconeogenesis Reduces peripheral glucose uptake Stimulates peripheral release of glycogenolysis precursors - lipolysis - muscle glycogenolysis and breakdown

Question 53

What happens is blood glucose >6 (too high)

Answer 53

Short-term - make glycogen (glucose to glycogen = glycogenesis) Long-term - make triglyceride (lipogenesis)

Question 54

What happens if blood glucose is <4 (too low)

Answer 54

Short term - split glycogen (glycogen to glucose = glycogenolysis) Long term - make glucose (gluconeogenesis) from amino acids/lactate

Question 55

Where are primary glucose sensors

Answer 55

Pancreatic islets Also in medulla, hypothalamus, carotid bodies Sensory cells in gut wall stimulate insulin release - incretins

Question 56

Describe insulin secretion by the B-cell

Answer 56

Glucose enters cell via GLUT2 glucose transporter Glucose metabolism into cell Ca2+ channels open Insulin secretory granules Insulin secretion

Question 57

Describe insulin release by proinsulin

Answer 57

Contain A and B chains of insulin joined by C peptide Presence of C peptide implies endogenous insulin production

Question 58

Describe biphasic insulin release

Answer 58

B-cells sense rising glucose and aim to metabolise it 1st phase response is rapid release of stored product 2nd phase response is slower and as it is release of newly synthesised hormone