GI IV Flashcards
Glisson’s capsule
fibrous CT
made of type III collagen (reticular) fibers
richly innervated
deep to visceral peritoneum
______ fibers from Glisson’s capsule penetrate into the liver ________
reticular
parenchyma
Classic hepatic lobule
hexagonal plate of hepatocytes and sinusoids
Portal canal
3-6 found at the angles
What does the portal canal contain?
CT
portal triad
lymphatic vessels
autonomic nerve fibers
What are the branches of the portal triad?
hepatic artery
portal vein
bile duct
Periportal space (space of Mall)
area between the hepatic lobule and the portal triad
believed to originate from lymphatics
Can’t see well defined borders of the liver lobule because it lacks _____
developed CT
What is the blood supply of the liver?
portal vein (75%) hepatic artery proper (25%)
Portal vein
- blood enters lobule via inlet venule
- inlet venule dumps into hepatic sinusoidal capillaries between hepatocytes
- rich in nutrients from GI tube
hepatic artery proper
- blood enters lobule via arteriosinusoidal branch
- arteriosinusoidal branch dumps into hepatic sinusoidal capillaries between hepatocytes
- rich in oxygen
Kupffer cells
phagocytes cells that remove pathogens from blood
also remove worn out RBCs
cause internal volume of RBCs to decline
Space of Disse (perisinusoidal space)
space between epithelial cells and hepatocyte cytoplasm
occupied by numerous hepatocyte microvilli
also contains hepatic stellate cell
Hepatic Stellate cell
signature feature is large lipid droplet
vitamin A stored here
Hepatic acinus
diamound shaped area
extends from a central vein to a hepatic canal to another, adjacent central vein to a second hepatic canal then back to the original central vein
What are the zones of the hepatic acinus and which is most susceptible to damage?
1, 2, 3
3 is most susceptible
Zone 1
closest to blood supply
has more oxygen and extrahepatic hormones
has more enzymes for glucose liberating and fatty-acid-oxidation
Zone 3
closest to central vein
has more enzymes for glycolysis, fatty acid synthesis, and detoxidifcation
Organelles in hepatocytes
rER for protein synthesis
sER for detox
mitochondria to provide fuel
Protein synthesis and carbohydrate storage require what?
a well developed rER
What happens to colloid osmotic pressure and blood clotting with severe liver injury
edema (because of less albumin)
longer clotting time (because of less clotting factors)
Unconjugated (indirect) bilirubin
water insoluble
released from lysed RBCs
conjugated (direct) bilirubin
what you get after liver modifies the unconjugated bilirubin to make it soluble
Dubin Johnson Syndrome
defect in MDR-2
pt presents with elevated levels of direct bilirubin
relatively benign
Gilbert Syndrome
decreased conjugation (by UGT1A1) benign condition
Type I crigler-najjar syndrome and neonatal hyper-bilirubinemia
absent conjugation
fatal
Type II crigler-najjar syndrome and neonatal hyper-bilirubinemia
decreased conjugation
can be benign
Alcoholic liver disease
fatty liver
damage is reversible
Alcoholic cirrhosis
irreversible
liver has a bunch of nodules
liver is highly dysfunctional
Stellate cells
normally dormant
injury/insult activates it and makes it start to proliferate
become contractile/constrict blood flow
Bile canaliculus
formed by membranes of hepatocytes
beginning portion of the bile collecting system
Canal of Hering
stem cell niche
lined by cholangiocytes and hepatocytes
Periductular null cells
sit in the periportal space
can regenerate liver cells
Layers of a normal gallbladder
mucosa (epithelium, BL, and lamina propria)
muscularis
CT layer of serosa/adventitia
Hallmark feature of inflamed gallbladder
purple specks that are inflammatory cells
Cholesterolosis
elevated cholesterol levels leading to formation of foam cells in gallbladder
benign, reversible
What do acinar cells in the exocrine pancreas secrete?
enzymes
What do ductal cells in the exocrine pancreas secrete?
water and ions (HCO3-)
Acute pancreatitis
enlarged pancreas with shaggy margins
peripancreatic fat infiltration
elevated serum amylase and lipase
