Chapter 9: Hepatobiliary System
A. Wong and R. Jennings
The liver is the largest visceral organ in the body. This chapter will cover the hepatobiliary system.
Chapter Learning Objectives
By the end of this chapter, you should be able to do the following:
- Compare and contrast the hepatocyte, Kupffer cell, Ito cell and Pit (immune) cell in terms of location within the liver, function, and important structural and ultrastructural features.
- State the various cytoplasmic components of the hepatocyte that contribute to the cytoplasmic eosinophilia evident by light microscopy.
- Discuss the unique ultrastructural characteristics of sinusoidal endothelial cells with regard to their role in the exchange of blood and nutrients.
- Recall the hepatobiliary locations in which the plasma membrane is modified by microvilli.
- List the components of the connective tissue stroma within the liver and identify the special histochemical stains used to visualize the different components.
- List the structures present in the portal tract and illustrate the directional flow of blood, lymph and bile.
- Explain the processes of biotransformation and recognize the role of these phases within other functions of the liver.
- Relate the different forms of bilirubin measured in the serum to bilirubin metabolism and their utility in localizing the mechanism of hyperbilirubinemia.
- Describe the interrelated role of the liver in the synthesis of lipids and proteins.
- Illustrate the different schemes used to describe the organization structure of the liver.
- Relate the structural and ultrastructural features of the gall bladder mucosa to the primary functions of the gall bladder.
By the end of this chapter, you should be able to answer the following:
- What regions of the liver are most susceptible to hypoxemia (low blood oxygen) and why?
- In cases of suspected toxicoses (e.g. anticoagulant toxicity, NSAID toxicity), the liver is often an organ requested for diagnostic testing for toxic compounds. What are some reasons that the liver is often tested for toxic compounds in suspected cases of toxicosis?
- What regions of hepatocytes in the hepatic lobule are most susceptible to direct-acting toxins, and why? What regions of hepatocytes are most susceptible to metabolized toxins and why? (hint: consider the different zones of hepatic lobules and their locations and functions)
- Hypoalbuminemia may be the result of reduced production of albumin or increased loss of albumin. What cell is the primary producer of albumin? What are some additional clinical and/or diagnostic findings that would be associated with reduced production of albumin? What are some conditions associated with reduced production of albumin?
- A porto-systemic shunt is formed when the portal circulation bypasses the liver and, instead, flows into the systemic venous circulation (most frequently as the result of a congenital vascular malformation). What are some possible consequences of blood from the portal circulation bypassing the liver? (Hint: recall the normal physiologic functions of the liver) (additional reading available through OSU libraries)
- Gall bladder disease, if severe and prolonged, may eventually result in intra-hepatic disease, as measured by an increase in ALT, AST and ALP. What are some possible mechanisms by which gall bladder disease leads to hepatocellular damage?