Liver GB Pancreas Flashcards
Liver and GB
Largest exocrine organ
Synth and secrete proteins, bile
Thrombopoietin (goes to bone marrow to make platelets) (kidney produces erythropoietin for RBC)
Hormones
Glycogen storage
Eliminate waste (takes over role of spleen when gone)
DETOX many SER
GB stores bile
SER
Glycogen breakdown
Detox
When blood glucose is high the liver
Secretes insulin to remove glucose from the blood and become part of the glycogen storage
Liver structure
DIRCT around entire liver
Parenchyma is the meat of the liver
Stroma
Little CT in liver otherwise it can turn into fibrosis. Cirrhosis
Hepatocytes line up in plates and between plates there are sinusoidal caps
Between these is reticular fibers that support
Portal triad
Hepatic artery- supplies liver with oxy blood , 25% flow
Bile duct- takes bile out, to the gall bladder to store
Portal vein- brings blood to liver that is deoxygenated from GIT, needs to be detoxified in liver, leave through inferior vena cava
Lymph vessels surrounding
Classic liver lobule
Portal lobule
Hepatic acinus
Classic- hexagon, central vein center, portal triads at corners
Portal- triangle, center is bile duct of portal triad, central veins are corners
Hepatic- diamond, corners are 2 portal triads and 2 central veins
Blood path
Bile path
Blood- triad to central vein
Out to in
Bile- hepatocytes make bile and then it travels to the portal triad to exit
IN TO OUT
Space of disse
Ito cells
Perisinusoidal space, between sinusoid and hepatocytes
Microvilli from hepatocytes are here
Ito cells- Stellate cells
Store vitamin A for sperm development, vision, limb and lung development
In disease ito diff into myofibroblast which causes scarring and may lead to cirrhosis
Bile track
Made by hepatocytes
That connect via bile canaliculi —-> ductules—-> bile duct
Glissons capsule
DIRCT covering liver
Hepatic acinus zones
Ordered like
3 2 1 2 3 in diamond formation
- In center closest to portal arteries, highest oxygen and toxin amounts
- Middle
- Outer closer to central veins, lowest oxygen and toxin amounts
High toxins amounts will affect which hepatic acinus zone the most?
What about low oxygen levels?
Zone 1 Because toxin concentration is highest in this zone
Zone 3 because it is already lowest in o2 conc
Pig has a higher what in the liver
Increased CT amounts around lobules, visible in slide
Human CT is not usually visible in a slide
What liver organization describes the exocrine function of the liver
The portal lobule triangle
Because the bile duct is the central part
And the central veins are the corners
The bile travels from the central canals to the bile duct to head to GB
What liver organization describes the parenchyma of liver
The hepatic acinus, diamond
Because the center of diamond lies on the parenchyma
Fenestrae
On the sinusoidal cap making the liver sinus
Microville from hepatocytes protrudes through to lumen of sinusoid
Kuppfer cells
Hepatic Macrophages that line the sinusoids of the liver
Bile made of and function
Lipids, RBC breakdown products
Bile salts, bilirubin
Emulsification/absorption of fat in smal intestine
Vitamin A function
Stored in ito cells in space of disse
Sperm development
Eye
Limb
Proper placement of cardiac neural crest cells
Gall bladder structure and functions
Conc bile
Concentrates and stores bile in mucosa layer
Thick musc externa to expel bile into duodenum
Highly polarized and folded mucosa
Bile conc done by epithelial cells in mucosa
Microvilli improve absorption with Na/K pumps
Pump Na/k out of lumen creating osmotic pressure
That osmotic pressure brings water from the bile to the caps in LP of mucosa
Pancreas structure and functions
Exo vs endo
Lobules surrounded by ct
Exocrine functions- stain darker
- Acinar cells- produce digestive enzymes> intercalated duct> larger ducts> pancreatic duct> duodenum
- Bicarbonate made by centroacinar cells in acinus intercalated duct
Endocrine functions- hormones,
Done in islets of Langerhan- lighter spots in histo, looks like circles of lighter tissue
With beta, alpha, d, and pp cells
Path taken by bicarbonate to duodenum
Acinar cells- produce digestive enzymes and bicarbonate by centroacinar > intercalated duct> larger ducts> pancreatic duct> duodenum
Cells in islets of langerhan
Beta
Alpha
D
PP
Beta- insulin, turns glucose into glycogen to decrease blood sugar
Central
Alpha- glucagon, glycogen breakdown, opposite of insulin
Edge
D- somatostatin, inhibits insulin and glucagon secretion
Dotted at edge
PP- inhibits enzyme and bicarbonate release
*BAD PP
Stellate cell of pancreas
Also known as ito cells, but these are bad
Normally quiescent but can be Culprit of pancreatic cancer
Triggered by GF
When active secretes ECM which makes it easier for cancer cells to move through pancreas
