Podcast
Questions and Answers
What cellular change occurs in hepatic fibrosis that negatively affects liver function?
What cellular change occurs in hepatic fibrosis that negatively affects liver function?
Which cell type is primarily responsible for the remodelling of the extracellular matrix in chronic liver disease?
Which cell type is primarily responsible for the remodelling of the extracellular matrix in chronic liver disease?
What is the primary metabolic function of the liver concerning ammonia?
What is the primary metabolic function of the liver concerning ammonia?
Which of the following is NOT a function of the liver?
Which of the following is NOT a function of the liver?
Signup and view all the answers
How does the activation of Kupffer cells affect hepatic stellate cells during liver injury?
How does the activation of Kupffer cells affect hepatic stellate cells during liver injury?
Signup and view all the answers
What is a consequence of liver dysfunction related to lipid metabolism?
What is a consequence of liver dysfunction related to lipid metabolism?
Signup and view all the answers
Which type of lipoprotein is synthesized and secreted by hepatocytes?
Which type of lipoprotein is synthesized and secreted by hepatocytes?
Signup and view all the answers
What function does the liver perform related to vitamins and minerals?
What function does the liver perform related to vitamins and minerals?
Signup and view all the answers
What is the primary function of Kupffer cells in the liver?
What is the primary function of Kupffer cells in the liver?
Signup and view all the answers
Which cell type in the liver is specifically noted for its ability to perform phagocytosis?
Which cell type in the liver is specifically noted for its ability to perform phagocytosis?
Signup and view all the answers
What prevents proteins from leaking out of the blood into the extracellular fluid in the liver?
What prevents proteins from leaking out of the blood into the extracellular fluid in the liver?
Signup and view all the answers
What role do lymphatic vessels play concerning the liver?
What role do lymphatic vessels play concerning the liver?
Signup and view all the answers
How does the structure of sinusoids in the liver differ from typical capillaries?
How does the structure of sinusoids in the liver differ from typical capillaries?
Signup and view all the answers
What triggers an increase in the number of Kupffer cells present in the sinusoids?
What triggers an increase in the number of Kupffer cells present in the sinusoids?
Signup and view all the answers
What is the primary role of hepatic receptors in lipoprotein metabolism?
What is the primary role of hepatic receptors in lipoprotein metabolism?
Signup and view all the answers
What is transported in the core of very-low-density lipoprotein (VLDL) particles?
What is transported in the core of very-low-density lipoprotein (VLDL) particles?
Signup and view all the answers
What is NOT a function of Kupffer cells in the liver?
What is NOT a function of Kupffer cells in the liver?
Signup and view all the answers
Which lipoprotein metabolic pathway is associated with lipoprotein lipase (LPL)?
Which lipoprotein metabolic pathway is associated with lipoprotein lipase (LPL)?
Signup and view all the answers
Which component of the liver lobule drains into bile ducts?
Which component of the liver lobule drains into bile ducts?
Signup and view all the answers
What role does ATP binding cassette transporter 1 (ABCA1) play in lipoprotein metabolism?
What role does ATP binding cassette transporter 1 (ABCA1) play in lipoprotein metabolism?
Signup and view all the answers
What is a key characteristic of intermediate-density lipoprotein (IDL)?
What is a key characteristic of intermediate-density lipoprotein (IDL)?
Signup and view all the answers
What component is primarily utilized by hepatic triglyceride lipase (HTGL) in lipid metabolism?
What component is primarily utilized by hepatic triglyceride lipase (HTGL) in lipid metabolism?
Signup and view all the answers
Which protein is recognized by LDL receptors in lipoprotein uptake?
Which protein is recognized by LDL receptors in lipoprotein uptake?
Signup and view all the answers
What is the function of lecithin:cholesterol acyltransferase (LCAT) in lipoprotein metabolism?
What is the function of lecithin:cholesterol acyltransferase (LCAT) in lipoprotein metabolism?
Signup and view all the answers
What is the primary function of bile acids in the digestion process?
What is the primary function of bile acids in the digestion process?
Signup and view all the answers
What triggers the contraction and emptying of the gallbladder?
What triggers the contraction and emptying of the gallbladder?
Signup and view all the answers
How much bile typically enters the duodenum each day?
How much bile typically enters the duodenum each day?
Signup and view all the answers
What percentage of the bile acid pool is normally excreted in the feces each day?
What percentage of the bile acid pool is normally excreted in the feces each day?
Signup and view all the answers
Which of these compounds is NOT a significant component of bile?
Which of these compounds is NOT a significant component of bile?
Signup and view all the answers
Which part of the intestine is primarily responsible for the active absorption of bile acids?
Which part of the intestine is primarily responsible for the active absorption of bile acids?
Signup and view all the answers
What happens to cholesterol levels in bile when drugs that inhibit bile acid reabsorption are used?
What happens to cholesterol levels in bile when drugs that inhibit bile acid reabsorption are used?
Signup and view all the answers
What role does the enterohepatic circulation play in bile acids?
What role does the enterohepatic circulation play in bile acids?
Signup and view all the answers
What are the two primary bile acids synthesized by the liver?
What are the two primary bile acids synthesized by the liver?
Signup and view all the answers
How do bile acids increase their solubility in bile?
How do bile acids increase their solubility in bile?
Signup and view all the answers
Which statement about conjugated bile acids is true?
Which statement about conjugated bile acids is true?
Signup and view all the answers
What happens when bile acids reach the critical micelle concentration?
What happens when bile acids reach the critical micelle concentration?
Signup and view all the answers
What role does lecithin play in bile?
What role does lecithin play in bile?
Signup and view all the answers
What are the consequences of excess cholesterol in bile?
What are the consequences of excess cholesterol in bile?
Signup and view all the answers
Which of the following statements regarding secondary bile acids is correct?
Which of the following statements regarding secondary bile acids is correct?
Signup and view all the answers
What feature of bile acids contributes to their ability to form micelles?
What feature of bile acids contributes to their ability to form micelles?
Signup and view all the answers
Which of the following proteins is NOT synthesized by the liver?
Which of the following proteins is NOT synthesized by the liver?
Signup and view all the answers
What role does the sphincter of Oddi play in bile secretion?
What role does the sphincter of Oddi play in bile secretion?
Signup and view all the answers
Which component is primarily synthesized by hepatocytes and contributes to bile composition?
Which component is primarily synthesized by hepatocytes and contributes to bile composition?
Signup and view all the answers
How does bile duct secretion differ from plasma in terms of bicarbonate concentration?
How does bile duct secretion differ from plasma in terms of bicarbonate concentration?
Signup and view all the answers
Which statement about gallbladder contraction is accurate?
Which statement about gallbladder contraction is accurate?
Signup and view all the answers
What is the primary function of protease inhibitors produced by the liver?
What is the primary function of protease inhibitors produced by the liver?
Signup and view all the answers
Which protein serves as a carrier for copper in the plasma?
Which protein serves as a carrier for copper in the plasma?
Signup and view all the answers
Which bile constituents are specifically secreted by hepatocytes into bile canaliculi?
Which bile constituents are specifically secreted by hepatocytes into bile canaliculi?
Signup and view all the answers
Study Notes
Liver and Gallbladder Functions
- The liver and gallbladder are crucial for various bodily functions.
- The liver has vascular functions, storing and filtering blood.
- The liver has secretory functions, secreting bile into the gastrointestinal tract.
- The liver performs metabolic functions.
Liver Structure
- Liver lobules are organized around central veins.
- Blood enters sinusoids from the portal vein and hepatic artery.
- Blood flows towards the center of the lobule between hepatic cells.
- Hepatic cells are one or two hepatocytes thick.
- Sinusoids have large gaps between endothelial cells.
- The normal Starling equilibrium does not operate in the liver.
- Fluid is readily leaked into the extracellular fluid.
- Lymph in the liver returns fluids from the liver through the thoracic duct and subclavian vein.
- The liver produces about 1/3 to 1/2 of the lymphatic fluid in the body.
Kupffer Cells
- Kupffer cells are specialized macrophages in the sinusoids.
- They express complement receptor (CRlg).
- Their function is to catch pathogens.
- Their number increases when particulate matter or debris is present in the blood.
Kupffer Cell Functions
- Phagocytosis of micro-organisms (bacteria, viruses).
- Endotoxins removal.
- Immune complexes removal.
- Tumour cell removal.
- Lipid assemblies removal.
- Fibrin degradation products removal.
- Other particulate matter removal.
- Modulation of acute phase proteins and lipoproteins synthesis.
- Cytokine secretion.
- Antigen processing.
- Glycoproteins and lipids catabolism.
Hepatic Circulation Zones
- Liver acinus is divided into three circulatory zones surrounding the portal axis.
- Zone 1 hepatocytes are close to the portal axis and are bathed in blood rich in nutrients and oxygen.
- Zone 1 cells are most active for oxidative metabolism and bile acid uptake.
- Zone 3 cells are near the central vein and receive blood already exchanged nutrients and oxygen in Zones 1 and 2.
- Zone 3 cells are mainly geared towards anaerobic metabolism.
- Zone 3 cells are sensitive to ischemia, nutritional deficiency, and toxic substances.
Hepatic Blood Flow
- Total hepatic blood flow accounts for approximately 25% of cardiac output.
- Portal vein supplies 70-75% of liver blood supply.
- Hepatic artery supplies 25-30%.
Liver as a Blood Reservoir
- The liver is a significant blood reservoir in humans.
- It contains 25-30 ml of blood per 100 grams of tissue.
- Liver blood volume can expand to 60 ml/grams of liver with cardiac failure.
- It plays a crucial role during hemorrhage.
Bile Secretion and Composition
- Bile is elaborated by hepatocytes.
- It contains bile acids, cholesterol, lecithin, and bile pigments.
- Hepatocytes secrete bile constituents into the bile canaliculi.
- Bile is an isotonic fluid similar in concentrations of Na+, K+, Cl−, and HCO3− to plasma.
- Bile duct epithelium secretes a watery bicarbonate-rich fluid.
- The fluid contributes to bile volume.
- Secretion of bile duct epithelium is stimulated by secretin.
- Bile, without secretin, does not increase the concentration.
Bile Concentration in Gallbladder
- Bile is diverted to the gallbladder between meals.
- The Gallbladder is a small organ with 15-60 ml capacity (average 35ml).
- The volume may be more than what liver secretes between meals.
- Gallbladder concentrates bile by absorbing Na+, Cl−, HCO3− and water.
- Bile acid concentration increases 5 to 20 times in gallbladder.
Bile Acid Absorption and Transport
- Bile acids are absorbed primarily in the terminal ileum.
- Active transport system in ileum has higher affinity for conjugated bile acids.
- Bile acid absorbed by either active transport or simple diffusion.
- Bile acids move from intestine into portal blood and are bound to plasma proteins.
- Hepatocytes absorb bile acids from portal blood.
- The hepatocytes then reconstitute the original structure.
- Bile acids are secreted into bile with newly synthesized bile acids.
Choleretic Effect and Excretion
- The rate of bile acid return to the liver influences synthesis and secretion.
- Bile acids stimulate secretion but inhibit synthesis, called choleretic effect.
- Choleretics enhance secretion.
Liver and Biliary Pain
- Pain may be from stretching liver capsule over right hypochondrium.
- or stretching of bile duct or gallbladder, mid epigastrium or right subcostal region.
- Rarely, pain is experienced below the scapula.
Bile Pigments and Gallstones
- Bilirubin is a yellow pigment in bile.
- Bilirubin may form in the intestines as urobilinogen.
- Most urobilinogen is returned to liver and re-secreted in bile.
- A small amount is absorbed into general circulation and then excreted by the kidneys.
- Bile pigments that form gallstones called calcium salts of unconjugated bilirubin.
- Individuals with liver disease have a higher chance of gallstones formation.
Phospholipids in Bile
- Liver secretes phospholipids, mainly lecithin.
- Cholesterol dissolves into the middle of micelles.
- Lecithin is amphipathic; it buries its fatty acyl chains inside the micelle and its hydrophilic surface faces water, thus solubilizing cholesterol.
Other Liver Details
- Jaundice: yellowing of skin and mucous membranes.
- Jaundice occurs when bilirubin levels elevate to more than 2 mg/dl.
- Hepatic diseases, reduced intracellular bilirubin uptake, failure in intracellular protein binding, impaired secretion or biliary obstruction can cause jaundice.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
