GI IV Flashcards
What is the CT that surrounds the liver called? What is it made of?
Glisson’s capsule–collagen III
What makes up the framework of the liver?
Reticular fibers
Is glisson’s capulse innervated by nerves?
Yes
What is just superficial to Glisson’s capsule?
The visceral peritoneum
What is the shape of the classic hepatic lobule? What is in the center of these lobules? At the corners?
Hexagon
Center = central vein
Corners = hepatic veins and arteries
What are the three components of the portal triad?
- Branches of hepatic artery
- Portal vein
- Bile duct
What are the spaces that are located between the CT and adjacent hepatocytes?
Periportal spaces (spaces of Mall)
A site of lymph origin
What is the epithelial lining of bile ducts?
Simple cuboidal epithelium
What is the blood suppler to hepatic lobules?
portal vein and hepatic artery
Where are Kuppfer cells located in the liver?
Hepatic sinusoids
What is histologically significant about the sinusoidal endothelium? Does it have a BL?
Fenestrated endothelium with absent or very discontinuous BL
What space sits between the endothelium of the hepatic sinusoids, and the hepatic cells? What specialization is present here?
Perisinusodial space, filled with Microvilli
What is the unique signature feature of hepatic stellate cells? Where are these cells found?
Lipid material (vit A)
These cells are found in the perisinusoidal space
What are the apexes of hepatic acini?
Central vein, to two triads
How are the zones of the hepatic acini arranged?
1, 2, 3, with 1 being close to triads, and 3 being close to the central vein
Which cells in hepatic acini are most susceptible to damage? Why?
Cells in zone 3, because of decreased oxygen supply and increased metabolic waste
What are the three enzymes that are high in concentration in zone 3 of hepatic acini?
Glycolysis
FA synthesis
Detox
What are the four chemicals/enzymes that are high in concentration in zone 1 of hepatic acini?
- Oxygen
- extrahepatic hormones
- Glucose liberating enzymes
- FA oxidation enz
Which zone of the hepatic acini are in the perilobular region? Centrolobular?
Perilobular = 1 Centrolobular = 3
What happens to colloid osmotic pressure when there is damage to the liver?
Goes down d/t decrease albumin
What happens to blood clotting when there is severe damage to the liver?
Clotting time increased d/t lower fibrinogen/prothrombin synthesis
What produces bile acids?
sER of hepatocytes
What is the function of the liver in the heme degradation pathway?
Conjugate bili
What is Dubin-johnson syndrome?
decreased secretion of conjugated bilirubin due to the absence of the mdr-2 canalicular transport protein
What is Gilbert syndrome?
Decreased conjugation of bili
What is Crigler-Najjar syndrome? What are the two types?
bilirubin conjugation is reduced (type II) or absent (type I)
What happens to the liver in alcoholic cirrhosis?
Increased deposition of collagen
What are the cells that are responsible for the CT deposition in alcoholic cirrhosis? What else do they do?
Stellate cells deposit collagen, divide, ad become contractile (causes ischemia)
What is the beginning portion of the bile duct system?
Bile cannuliculus
What limits bile canaliculi?
The plasma membrane of two hepatocytes
What is the canal of Hering?
The beginning of a bile duct
What are the two stem cell types found within a bile duct?
Ductular cells and periducular null cells
What are the canals of Hering lined by?
lined by simple cuboidal cholangiocytes and hepatocytes; stem cell niche
What type of epithelium are the bile ducts lined by?
Simple cuboidal to columnar
What type of epithelium are the hepatic ducts lined by?
Simple columnar epithelium
What type of junctions exist between hepatic cells in the bile duct?
Tight junctions
What are the three layers of the gallbladder?
- mucosa
- muscularis
- CT layer
Is there a muscularis mucosa in the gallbladder?
no
What type of epithelium comprises the gallbladder?
Simple columnar epithelium
What are the sinuses that are located in the gallbladder called? What layer of the gallbladder can these extend through?
Rokitansky-Aschoff sinuses may extend through muscularis
What is cholesterolosis?
Benign accumulation of cholesterol in the gallbladder by macrophages
How is the muscularis of the gallbladder orientated?
random
What type of CT surrounds the gallbladder?
Dense collagenous CT
What type of membrane is found on the peritoneal surface of the gallbladder? Hepatic surface?
Serous membrane (serosa) on its peritoneal surface and adventitia on its hepatic surface
The gallbladder does not have a submucosa or serosa on its hepatic surface. What is the clinical significance of this?
facilitates invasion of GB cancer to the liver
What type of glands are in the pancreas?
Compound acinar
The base of pancreas cells rest on what?
A Basal Lamina
Is the base of pancreas cells acidophilic or basophilic? The apex?
Apex = acidophilic Base = basophilic
What type of epithelium lines the intercalated ducts of the pancreas?
Simple cuboidal
What do pancreatic duct cells secrete?
Water, HCO3
What are the two primary causes of pancreatitis?
EtOH use and gallstones
