Liver & Pancreas Flashcards
What is contained within the portal tract/triad at the periphery of hepatic lobules?
- venule branch of the portal vein
- arteriole branch of the hepatic artery
- bile ductules of the bile conducting system
What lines the bile ductules?
-simple cuboidal epithelium of cholangiocytes
What kind of intermediate filament is found within hepatocytes?
- cytokeratin
- technically an epithelial cell
Do hepatocytes have a basement membrane?
No
What are the three surfaces of hepatocytes?
- basolateral
- lateral
- apical
Which surfaces of the hepatocyte are facing the blood sinousoids?
-basolateral
What do blood sinusoids arise from?
-conjoining of the hepatic portal venules and hepatic arterioles of the peripheral lobules
What is the space of disse?
-fenestrations in the capillary endothelium which allow microvilli from the hepatocytes to contact blood in the sinousoids
On what surface of the hepatocytes does the exocrine function occur?
-the apical surface
What do the bile canaliculi empty into?
-the canal of hering, which empties into the bile ductule of the portal tract
What cells are stellate macrophages?
-Kupffer cells
What do kupffer cells do?
- garbage trucks of the liver
- monocyte derivatives
- APCs, eat old blood cells, degrade hemoglobin to bilirubin, store iron, remove bacteria and debris from the portal blood
Where do kupffer cells live?
-sinusoid lining
What cells are hepatic stellate cells?
- Ito Cells
- Lipocytes
From what tissue do hepatic stellate cells arise?
-mesenchyme
What do hepatic stellate cells do?
- produce ECM
- Store fat soluble vitamins
- secrete cytokines
Which vitamins are fat soluble?
A
D
E
K
Where do hepatic stellate cells live?
-perisinusoidal space
Is there muscularis mucosa in the gallbladder?
-No
Tell me about the muscularis externa of the gallbladder.
- it is made of a random organization of smooth muscle
- Contraction is caused by CCK
What makes up the exocrine portion of the pancreas?
secretory acini
What makes up the endocrine portion of the pancreas?
-pancreatic islets
What lines the intercalated duct of the pancreas?
simple squamous epithelium
What cells are present at the extensions of the intercalated duct into the lumen of the acini?
-Centroacinar cells
What is the structure of the classic lobule of the liver?
-drains blood from the portal vein and hepatic artery to the central vein
What is the structure of the portal lobule?
- Drains bile from hepatocytes to the bile duct
- triangle
What is the structure of the hepatic acinus lobule?
-shows supply gradient of oxygenated blood to hepatocytes
How does liver cell regeneration occur?
via proliferation from existing hepatocytes or stem cells (oval cells)
What are oval cells? Where do they live?
- stem cells of the liver
- can proliferate into hepatocytes or cholangiocytes
-live among the cholangiocytes int he bile canals
What portion of the pancreas are most islets of langerhans located?
the tail
What do A (Alpha) cells of the pancreas secrete?
Glucagon
What do B (Beta) cells of the pancreas secrete?
-insulin
What do D cells of the pancreas secrete?
-somatostatin
What do PP cells of the pancreas secrete?
pancreatic polypeptides that:
- stimulate chief cells
- inhibit bile secretion
- inhibit pancreatic enzyme secretion
- inhibit intestinal motility
What are the three pairs of salivary glands?
- parotid
- Submandibular
- Sublingual
How does the branching duct system of salivary glands modify saliva?
- adding growth factors and enzymes
- reabsorbing Na and Cl
Where are myoepithelial cells of the salivary glands located?
-the common basal lamina surrounding acini and tubules
What is the order of ducts in the salivary glands after the acinus?
- Intralobular: Intercalated then striated
- Interlobular
- Main duct
What are the two types of intralobular ducts, and what kind of epithelium do they exhibit? do they have myoepithelial cells?
- intercalated (cuboidal to columnar) Yes myoepithelial cells
- Striated (columnar) No myoepithelial cells
What types of epithelium does the interlobular duct exhibit?
- cuboidal/columnar
- pseudostratified
- stratified
What is the epithelium of the main salivary duct?
-nonkeratinized, stratified squamous epithelium
What is the effect of parasympathetic and sympathetic input on the quality of saliva secretions from the salivary glands?
Parasymphathetic: Watery with little protein
Symphathetic: Secretion inhibited. Secretions have high protein content
Which gland produces the most saliva?
-submandibular (70%)
What are serous demilunes?
-crescent shaped clusters of serous cells present in mixed salivary units
Where do demilunes live?
- mostly submandibular glands
- some in sublingual glands
Where are mucosal salivary glands located?
-throughout the oral mucosa
