Physiology-Liver and Gallbladder Flashcards
What plasma protein is not made by the liver?
Immunoglobulins, most other proteins are made by the liver.
Why call it the portal tract over the portal triad?
In addition to the hepatic artery, portal vein and bile duct, you also have nerves and lymphatics in the tract.
Where is blood exchanged in the liver?
Portal vein -> hepatic sinusoids (discontinuous capillaries) -> collecting vein. Note that oxygen rich blood coming from the hepatic artery also dumps into the sinusoids.
Why did these hepatocytes around the portal tract stain intensely with PAS?
Blood flows in from the intestines to the portal vein, which will be rich in nutrients. Cells closest to the portal tract are most metabolically active because protein synthesis is increased because nutrients are increased.
What cells are most likely to be damaged 1st in the liver during hypo perfusion?
Those furthest from the portal tract, they are furthest away from oxygen and nutrients (zone 3)
What type of capillaries are shown below?
Discontinuous capillaries are what make up the endothelium of the sinusoids
What type of secretory function is happening at the area indicated below?
This is the space of Disse, it separates the sinusoid from the basal aspect of the hepatocyte. The basal aspect of the hepatocyte secretes protein into the blood, an endocrine function. Also note that nutrients are taken across the space of Disse to the hepatocytes and the space of Disse marks the beginning of the hepatic lymphatics. Collagen bundles are also located in the space of Disse.
What do these cells do?
These are Kupffer cells. They are involved in host defense by digesting PMNs that phagocytosed invading microbes and regulation of iron by digesting worn out RBCs.
What cells allow the liver to regenerate as well as it does?
Oval cells located around the periportal area and bile ducts.
What hepatic cell stores fat and vitamin A? What happens when this cell causes problems?
Ito cell. In pathologic situations it becomes fibroblastic and can cause cirrhosis.
What marks the apical part of the hepatocyte?
Bile canaliculus
What component of bile is recycled well and what component not so well?
Well: bile salts. Not so well: bile pigment, this is what makes feces brown.
What is the overarching concept of cholelithiasis?
Decreasing the amount of lecithin or bile salts or increasing the amount of cholesterol in bile. Normally bile is 55% bile salt, 30% lecithin, 15% cholesterol.
Enterohepatic circulation
Liver makes bile -> Secretin induces bile secretion -> Bile is released, backs up at the sphincter to the gallbladder -> Gallbladder takes out water to concentrate water -> CCK/ACh release causes sphincter relaxation and gallbladder contraction
How is bile secretion regulated?
Bile acid-dependent bile flow (bile salt secretion, not regulated). Bile acid-independent bile flow (water & electrolyte addition to bile, regulated)
What happens in this condition?
Blockade of a major bile duct causes jaundice.
Where is this section taken from?
Note the squiggly mucosa, lack of connective tissue, single muscle layer an lack of glands next to liver, this is the gallbladder.
