lecture 1

Question 1

where is the pancreas located in the body?

Answer 1

the pancreas lies in the C-shape of the duodenum. Is essentially an accessory organ for the small intestine to provide enzymes. Lies just in front of major blood vessels.

Question 2

what is the sphincter of oddi?

Answer 2

the major duct passing into the middle of the duodenum which combines excretions from the hepatic ducts of the liver, excretions from the gallbladder and the main pancreatic duct.

Question 3

what are the primary functions of the exocrine pancreas?

Answer 3

neutralises stomach acid, deliver enzymes for macronutrient digestion in duodenum.

Question 4

what is the purpose of the acinar cells in the pancreas?

Answer 4

these are the main secretory cells in the pancreas (secrete enzymes and ion secretions) Clusters are connected by intercalated ducts. lining cells of the ducts add ions and secretions (e.g. HCO3-)

Question 5

how is the exocrine pancreas regulated in the cephalic phase?

Answer 5

by the vagus nerve which stimulates pancreatic secretions by releasing ACh and VIP. Accounts for near 25% of pancreatic secretions

Question 6

how is the gastric phase of exocrine pancreas stimulated?

Answer 6

medicated by vasovagal reflexes. Accounts fro near 10% of pancreatic secretions.

Question 7

how is the intestinal phase of exocrine pancreas secretion stimulated?

Answer 7

controlled hormonally by secretin (in response to H+) and CCK (in response to fatty acids, amino acids and monoacylglycerols) accounts for about 65% of pancreatic secretions

Question 8

what are zymogen granules?

Answer 8

granules which are present in acinar cells which house active and inactive digestive enzymes. Mostly secreted the inactive form.

Question 9

what stimulates the secretion of the zymogen granules?

Answer 9

hormones including CCK

Question 10

how are zymogen granules released from acinar cells?

Answer 10

by exocytosis into the luminal space. this exocytosis is regulated hormonally and neurally. Mainly by CCK binding to receptors on the acinar cells.

Question 11

which ions are affected by flow rate?

Answer 11

HCO3- concentration increases with increased flow rate and CL- concentration decreases with increased flow rate.

Question 12

are the concentration of sodium and potassium ions affected by the flow rate?

Answer 12

no

Question 13

where does the liver lie?

Answer 13

The liver lies in the upper abdomen, underneath the diaphragm, slightly to the right. surrounded by the peritoneum except for bare area related to the diaphragm. May be palpable below the costal margin.

Question 14

what is glisson’s capsule?

Answer 14

a thin connective tissue layer that sends extensions into the organ, in between the lobules.

Question 15

which blood vessel supplies the liver with nutrients?

Answer 15

the hepatic portal vein which brings absorbed nutrients from the stomach and gut.

Question 16

what is the hepatic artery?

Answer 16

a blood vessel which supplies the hepatocytes (liver cells) with oxygen.

Question 17

how is bile drained from the liver?

Answer 17

via canaliculi that lie between the hepatocytes into bile ductules which eventually become bile ducts which feed into the common hepatic duct.

Question 18

describe the lobes of the liver

Answer 18

left lobe: lies medially.
Right lobe also contains the caudate lobe which has a groove for the inferior vena cava and the quadrate lobe which houses the gallbladder.

Question 19

describe the synthesis and secretion of bile of the liver

Answer 19

the liver secretes bile which is composed of: bile pigments, cholesterol, phospholipids, fatty acids, water and electrolytes.

Question 20

what ere bile pigments derived from?

Answer 20

the breakdown of haemoglobin; kupffer cells are involved in their formation. Bile salts are responsible for the detergent and emulsifying effect of bile on fats, and also increase the absorption of fats by the small intestine.

Question 21

what direction is the flow of bile in relation to the flow of blood from the hepatic artery and portal vein?

Answer 21

the opposite direction

Question 22

where does the bile go if the sphincter of Oddi is contracted?

Answer 22

mainly to the gallbladder

Question 23

where does the bile go if the sphincter of Oddi is relaxed?

Answer 23

mainly to the duodenum

Question 24

what is the relaxation of the sphincter of Oddi mainly controlled by?

Answer 24

CCK

Question 25

how is bile concentrated?

Answer 25

by the movement of water out of it due to the reabsorption of sodium and chloride

Question 26

what is the primary role of the gall bladder?

Answer 26

to store and distribute bile in a concentrated form

Question 27

what stimulates the gallbladder to contract?

Answer 27

in response to CCK

Question 28

what inhibits the secretion of bile acid?

Answer 28

somatostatin and noradrenaline

Question 29

what is a metabolic function of the liver?

Answer 29

metabolism of carbohydrates, proteins and fats. Stores/releases carbohydrates (i.e. glycogenolysis, gluconeogenesis)

Question 30

what is a detoxification function of the liver?

Answer 30

removal of ammonia and ethanol and drug biotransformation

Question 31

what is an immune system function of the liver?

Answer 31

the removal of intestinal bacteria from portal blood so none is in the systemic circulation

Question 32

what is the main purpose of bicarbonate ion secretion from the pancreas?

Answer 32

to neutralise stomach acid.

Question 33

what other important materials does the liver store?

Answer 33

soluble vitamins and certain minerals

Question 34

what is another function of the liver related to the immune system?

Answer 34

production of large amounts of lymph