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Search Share Comments imes New Rom 12 - A Ă Aa-AEEEEET | Аавьссо| Аавьссос АавьсАавьссс Аав Аавьсаг Uab *, * A-DAE 11 Normal 1 No Spac. Heading 1 Heading 2 T Find - Replace Select- Title Subtitle Dictate Font Paragraph Styles Editing Voice A 4. Mrs. Fender's prolonged clotting times and excessive bruising are related Again, referring to normal physiological functioning of the liver, why do these two things happen when alcohol damages hepatocytes? 5. The liver has a portal vein as well as a hepatic vein. It also has unique exchange blood vessels similar to capillaries, called "sinusoids." How do these unique structures determine the function of the organ? 6. Cirrhosis leads to scarring and increased hydrostatic pressure in the hepatic portal vein. Explain why this increased venous pressure causes net filtration to increase in the hepatic capillaries leading to ascites (swollen and fluid-filled interstitial space of the abdomen) 7. Explain why the underproduction of albumin by a cirrhotic liver contributes to excessive filtration, which leads to ascites. Refer again to the forces that determine net filtration pressure in the hepatic capillaries, and to the function of albumins Focus W w a Insert ds o here to search

Answer 1

4) The liver plays a central role in the clotting process, and acute and chronic liver diseases are invariably associated with coagulation disorders due to multiple causes: decreased synthesis of clotting and inhibitor factors, decreased clearance of activated factors, quantitative and qualitative platelet defects, hyperfibrinolysis, and accelerated intravascular coagulation.

5) Sinusoids are low pressure vascular channels that receive blood from terminal branches of the hepatic artery and portal vein at the periphery of lobules and deliver it into central veins. Sinusoids are lined with endothelial cells and flanked by plates of hepatocytes.

The liver has a unique circulatory system. About 75% of the blood flowing through the liver comes from the portal vein, carrying venous blood from the intestines, stomach, pancreas, and spleen. This assures direct delivery of nutrient-rich blood to the liver, which will appropriately package, store, or release these nutrients as the body needs them. The other 25% of blood flow comes from the hepatic artery, which carries arterial blood from the abdominal aorta. This blood is oxygen-rich and refreshes the highly metabolic hepatocytes. At the terminal branches of the portal vein and hepatic artery, the blood mixes and flows into the liver capillaries, which are called sinusoids. The walls of the sinusoids are highly fenestrated, discontinuous epithelial cells that allow plasma and solute to leak into the interstitial space between surrounding hepatocytes. In essence, the blood "percolates" in the sinusoids on its way to the hepatic veins, and then to the vena cava. This percolation is ideal for hepatocytes to filter the blood, process and store nutrients, detoxify (e.g., remove ammonia), and remove debris (e.g., worn-out RBCs, bacteria).

6) In alcoholic cirrhosis, the portal vein becomes scarred and blocked, causing an increase in hydrostatic pressure (portal hypertension). This leads to an increase in capillary hydrostatic pressure. Alcoholic cirrhosis also causes the liver to underproduce albumin. This lowers osmotic pressure in the vasculature, enhancing filtration out of the capillaries. (Recall the effect of capillary hydrostatic pressure and osmotic pressure on net filtration.)

7) The liver is the major production site of albumins. Albumin (the main protein) is typically too large to diffuse across the capillary wall, so it remains in the blood vessels where they create an osmotic force that maintains water volume in the vasculature. In fact, albumins are the primary source of osmotic pressure, contributing to the reabsorption of water.