Test 2 - German - Pancreas, Liver, and Gallbladder Flashcards
Exocrine secretions go where?
Endocrine secretions go where?
Released onto a surface or into a duct
Released into the blood
Gallbladder is primary what kind of secretory organ?
Exocrine
The liver is primarily what type of secretory organ?
Endocrine
T/F - The pancreas is only an endocrine organ.
FALSE.
Exocrine has what type of cells and to they have distinct or diverse secretion types?
Epithelial cells. Diverse.
What are the three gland types of exocrine secretions and describe them?
Merocrine - Most common. Use exocytosis. Ex. Salivary glands.
Holocrine - Cells disintegrate to form secretion. “Holocaust” Ex. Sebaceous glands.
Apocrine - Membrane-enclosed apical cytoplasm (Like a large vesicle with proteins and lipids) Ex. Mammary glands.
What cells are key in the endocrine pancreas and what do they release?
Islet of Langerhans
Protein and polypeptide hormones
What cells are active in the exocrine pancreas and what do they release?
Acinar cells
Digestive molecules into the duodenum.
Exocrine Pancreas - What is zymogen?
Enzyme precursor
Acinar cells exocytose what into intercalated ducts?
Zymogen granules
What are in zymogen granules?
Alpha-amylase
Lipase
Nucleases
Proteases: trypsinogen, chymotrypsinogen, elastase
Where are zymogens activated and why?
In the duodenum to protect acinar cells
What do centroacinar cells produce?
HCO3-
CCK and secretin induce which cells to undergo exocrine activity?
Acinar and centroacinar
What is CCK?
Neuropeptide - I cells
What is secretin?
S cells
Alpha cells in the pancreas secrete what?
GLUCAGON
Beta cells in the pancreas secrete what?
INSULIN
Delta cells secrete what?
SOMATOSTATIN
This inhibits GI and pancreatic endocrine and exocrine secretion
PP cells secrete what?
Pancreatic polypeptide
This inhibits pancreatic exocrine, GI motility, gastric acid secretion
What are the functions of the liver?
Blood reservoir
Bile secretion
Detoxification
Metabolic homeostasis: carb meta, lipid meta, protein meta, storage, serum protein production
What are the 4 major functional cell types in the liver and what do they do?
Hepatocyte - Meta carbs, pro, lipids; produce bile from cholesterol; detox endogenous and foreign (xenobiotic) molecules
Kupffer - Macrophages
Sinusoidal Endothelial - Large pores b/t cells and no bsmt mem
Hepatic stellate - store lipids and vitamins; repair liver damage
The portal vein allows what in terms of drug metabolism?
First-pass
In regards to blood and the liver, what is the normal volume of blood?
The liver can expand it to what?
What do the Kupffer macrophage cells do?
450 mL
0.5-1 L
Filter blood, clear colon and intestinal bacteria
Name the three functional liver architecture classifications.
Classic Hepatic
Portal
Hepatic Acinus
Describe the classic hepatic lobule.
Hexagonal prism of portal canals
Blood drains from portal v and hepatic a to central v
Endocrine!
Describe the portal lobule.
Bile drains from hepatocytes to bile ducts
Exocrine!
Describe Hepatic acinus
3 zones
I - Periportal - O2 and nutrient rich - Carb meta
II - Intermediate
III - Peripheral - O2 poor - detox - These are the cells first damaged by hypoxic conditions
The liver detoxifies molecules in two phases. Describe phase I.
Molecule converted to more polar compounds - oxidized - cytochrome p450 and microsomal oxidases
Describe phase II
Molecules/Drugs/Phase I metabolites conjugated to hydrophilic molecules. Transferases
Metabolites eliminated in bile or urine
What is bile?
Bile salts, cholesterol, phospholipids, bilirubins, and waste. Produced by hepatocytes, stored in gall bladder, released into duodenum
What stims bile release?
CCK - this contracts gallbladder smooth m and relaxes hepatopancreatic sphincter
What does secretin do?
Stims HCO3- secretion in bile
