Liver / histology / discussion / viva / oral / questions

1. What type of gland is liver?
• Liver is both endocrine and exocrine gland
2. What are the functions of liver?
• Produces and secretes many circulating plasma proteins
• Plays an important role in uptake, storage and distribution of nutrients and vitamins from bloodstream
• Maintains blood glucose level
• Regulates circulating levels of very low density lipoproteins
• Degrades or conjugates numerous toxic substances and drugs
• Secretes bile containing salts, phospholipids, and cholesterol
3. What is Glisson’s capsule?
• It is the connective tissue sheath covering the liver. It is nothing but serous peritoneum covering liver.
4. Name the 3 functional units of liver
• Liver lobule or hepatic lobule or classic lobule
• Portal lobule
• Portal acinus or liver acinus
5. Describe hepatic lobule / What is hepatic lobule
• It is hexagonal unit where plates of liver cells or hepatocytes and sinusoids radiate towards periphery from central vein. At periphery it is bounded by portal triads.
6. What are portal triads?
• Portal triads are spaces containing connective tissue with branches of hepatic artery, hepatic portal vein and bile duct.
7. What is space of Mall?
• Space of Mall is the space present between the portal triad and radiating hepatocytes.
8. Describe portal lobule
• It is triangular area present between three central veins closest to one portal triad which includes three adjacent hepatic lobules. The bile secreted from this area drains into the bile duct in portal triad present in center of three adjacent hepatic lobules
9. Describe portal acinus or liver acinus
• It is diamond shaped area which includes two adjacent hepatic lobules close to axis defined by terminal branches of portal triad. The branch of hepatic artery supplies the two adjacent hepatic lobules. The part close to the axis receives more oxygenated blood compared to regions near the central veins which gets the least.
10. What are hepatic sinusoids?
• They are tortuous, dilated blood channels lined by discontinuous layer of fenestrated endothelial cells and phagocytic Kupffer cells. The exchange of materials occurs here between hepatocytes and blood.
11. What is space of Disse?
• The space present between the hepatocytes and the endothelial cells of sinusoids is called space of Disse.
12. What is the direction of blood flow in liver?
• Portal vein and hepatic artery à sinusoids à central vein à venules à veins à hepatic vein à inferior vena cava
13. What is direction of bile flow?
• Hepatocytes à bile canaliculi à bile ducts àlarge hepatic ducts
14. Name the fibers which form the supporting network in liver
• Reticular fibers line the sinusoids, support the endothelial cells and form dense network of reticular fibers in the wall of central vein
15. Where does the blood from hepatic artery and portal vein mix?
• Hepatic sinusoids
16. What is function of Kupffer cells?
• Kupffer cells are a type of macrophages which is phagocytic in nature lining the sinusoids.
17. What are the cells lining the sinusoids?
• Squamous cells
• Kupffer cells
18. What is the difference between space of Disse and space of Mall?
• Space of Disse is the space between the endothelial cells and hepatic cells
• Space of Mall is present between portal triad and hepatic cells
19. What is the difference between hepatic and portal lobule?
• Hepatic lobule: hexagonal unit with central vein and radiating hepatic laminae surrounded by portal triads at periphery
• Portal lobule: is the area where bile is drained by bile duct in the protal triad which is present between three central veins of adjacent hepatic lobules