Pancreas, Liver, and Gallbladder

Question 1

exocrine glands

Answer 1

secrete onto a surface by acinus cells
epithelial cells
diverse secretions

Question 2

endocrine

Answer 2

secrete into vasculature
epithelial and non-epithelial cells
exocytosis

Question 3

what are the three types of exocrine glands

Answer 3

1. merocrine-salivary glands, pancreas (exocytosis)
2. holocrine- sebaceous glands (secrete disintegrated cells)
3. Apocrine (secrete large micelles) mammary glands

Question 4

the pancreas endocrine function and exocrine function

Answer 4

endocrine: islets of langerhans, protein and poly. peptides hormones (insulin and glucagon)
exocrine: acinar cells (release digestive molecules into the duodenum aka enzymes)

Question 5

the exocrine pancreas

Answer 5

acinar cells exocytose zymogen granules into intercalated ducts

Question 6

zymogen granule enzymes

Answer 6

amylase
lipases
nucleases
proteases

Question 7

what is trypsinogen activated by?

Answer 7

enterokinase cleaves trypsinogen into trypsin

Question 8

what is chymotrypsinogen activated by?

Answer 8

trypsin cleaves chymotrypsinogen into chymotrypsin

Question 9

What is elastase activate by?

Answer 9

trypsin

Question 10

what do controacinar cells produce?

Answer 10

bicarbonate to create an alkaline soluition that flushes secretions into duodenum

Question 11

What does Cholecystokinin (CCK) and secretin do?

Answer 11

induce acinar and controacinar cells activity

Question 12

what cells release cholecystokinin(CCK) and secretin?

Answer 12

CCK by I cells

secretin by S cells

Question 13

the endocrine pancreas cells

Answer 13

30% alpha cells: secrete glucagon
65% beta cells: secrete insulin
4% delta cells: secrete somatostatin(inhibits GI and pancreatic endo and exocrine secretes
<1% PP cells: secrete pancreatic polypeptide (inhibits pancreatic exocrine secretion, GI motility, and gastric acid secretion
% referes to amount per islet of langerhan

Question 14

functions of the liver (4)

characteristics (3)

Answer 14

blood reservoir
bile secretion 
detox
metabolic homeostasis
largest organ
highly regenerative
dual blood supply, receives 30% of cardiac output

Question 15

what are the major cell types of the liver?

Answer 15

Hepatocyte
Kupffer
Sinusoidal epithelial cells

Question 16

Hepatocytes

Answer 16

polarized epithelial cells (they are sided)
metabolism carbs, proteins, lipids
produces bile from cholesterol
detoxifies endogenous and xenobiotics

Question 17

Kupffer cell

Answer 17

liver specific macs

removes pathogens and debris from the blood

Question 18

Sinusoidal Epithelial cells

Answer 18

large pores between cells (fenestrae)
No basement membrane
allow large proteins to pass through them

Question 19

how many lobes are in the liver and what is the rough size of lobules?

Answer 19

there are 8

3mm wide and 7 mm long

Question 20

what are the two major sources of blood for the liver?

Answer 20

the hepatic artery(30%) and the portal vein(70%)

Question 21

why is the portal vein said to allow first-pass metabolism?

Answer 21

blood comes from the GI and passes through the liver first.

acts as a sensor for blood concentration levels important signals

Question 22

classic hepatic lobule modle

Answer 22

• hexagonal prism of portal canals
• blood drains from portal vein and hepatic artery to central vein
• endocrine function focus model

Question 23

Portal lobule modle

Answer 23

bile drains from hepatocytes to the bile ducts

exocrine focus

Question 24

hepatic acinus

Answer 24

microvasculature
circulatory zones
gradient of hepatocyte oxygenation
hepatic functions differ across the 3 zones

Question 25

zone I

Answer 25

periportal zone, oxygen rich and nutrient rich

most active in regulating blood glucose and protein breakdown

Question 26

zone II

Answer 26

intermediate zone, less oxygen and nutrients than zone I

Question 27

zone III

Answer 27

peripheral zone, oxygen poor
large amount of detox enzymes
lowest blood flow
susceptible toxicity death

Question 28

ways the liver maintains systemic metabolic homestasis

Answer 28

• carb metabolism
• fatty acid metabolism
• protein metabolism (deaminates AAs, makes urea)
• storage(vitamins, FAs, Iron)
• protein production (clotting factors, albumin, -apoplipoproteins)

Question 29

liver detox phase I

Answer 29

Drugs/molecules converted to more polar compounds, oxidized

• cytochrome p450 and microsomal oxidases, makes drug inactivated
• makes a metabolite

Question 30

liver detox phase II

Answer 30

Drugs/molecules/Phase I metabolites conjugated to hydrophilic molecules(solubilizes them)
-transferase dumps them into bile duct to be excreted
also can be dumped into blood to be sent to kidney to be urinated out

Question 31

the liver produces bile, what is it?

Answer 31

a heterogeneous secretion, containing bile salts, cholesterol, phospholipids, bilirubin, and waste

Question 32

why is bile important?

Answer 32

cholesterol metabolism
alkalizes intestinal contents
detergent to solubilize dietary lipids and fatty acids
eliminates toxic endogenous waste and xenobiotics
it is recycled

Question 33

what does the gallbladder do?

Answer 33

it stores and secretes bile

Question 34

what stimulates the gallbladder?

Answer 34

• CCK by causing SM contraction and relaxes the hepatopancreatic sphincter aka ampulla of vater
• secretin stimulates bicarbonate for the bile to be secreted in.