Week 19 - Liver, Gallbladder, and Bilirubin Metabolism Flashcards

Flashcards on liver anatomy, blood supply, histology, bile flow, liver functions, gallbladder, hormonal control, red blood cell breakdown, and jaundice.

Where is the liver located relative to the diaphragm?

The liver is inferior to the diaphragm.

What separates the right and left lobes of the liver?

The falciform ligament.

Which lobe of the liver lies adjacent to the gallbladder?

The quadrate lobe.

What is the \"bare area\" of the liver?

The part of the liver not covered by peritoneum, in direct contact with the diaphragm.

What are the two main sources of blood to the liver?

The hepatic artery (oxygenated blood) and the hepatic portal vein (nutrient-rich, deoxygenated blood).

What vessels form the hepatic portal vein?

The splenic vein and the superior mesenteric vein.

Where does blood from the liver eventually drain?

Into the inferior vena cava via the hepatic veins (right, middle, left).

What are hepatic lobules?

Hexagonal functional units of the liver made up of hepatocytes organized around a central vein.

What are hepatic sinusoids?

Highly permeable capillaries between hepatic laminae where exchange occurs between blood and hepatocytes.

What three structures make up the portal triad?

A branch of the hepatic artery, a branch of the portal vein, and a bile duct.

What are Kupffer cells?

Liver macrophages in sinusoids that phagocytose pathogens and old red blood cells.

Which ducts form the common bile duct?

The common hepatic duct and the cystic duct.

Where does the common bile duct empty?

Into the duodenum at the hepatopancreatic ampulla (ampulla of Vater).

What direction does bile flow compared to blood in the liver lobule?

Bile flows in the opposite direction to blood.

What happens in the liver during high blood glucose levels?

Glycogenesis and lipogenesis occur—glucose is stored or converted to fat.

Name three non-metabolic functions of the liver.

Plasma protein synthesis, detoxification, bile production, vitamin/mineral storage.

What is the function of the gallbladder?

To store and concentrate bile.

What stimulates the gallbladder to release bile?

Cholecystokinin (CCK), released when fats enter the duodenum.

What is bilirubin?

A yellow pigment formed from the breakdown of heme in red blood cells.

What causes jaundice?

Accumulation of bilirubin in tissues due to liver dysfunction or bile duct blockage.

How are free fatty acids transported in the blood during the fed state?

They are bound to albumin proteins for transport.

What happens to triglycerides when blood glucose levels are high?

They are synthesized and stored in adipose tissue.

What are lipoproteins formed from?

Triglycerides and cholesterol.

What is cholesterol used for in the liver?

To continuously make bile.

What happens to fatty acids during fasting?

They undergo beta-oxidation to produce ATP and are used to generate ketone bodies.

What happens to glycerol during fasting?

It is used by the liver to make glucose.

What proteins are synthesized from amino acids in the fed state?

Albumin, globulin, prothrombin, fibrinogen, transferrin, ferritin, and lipoproteins.

What structural proteins are made from amino acids?

Proteins used in the cytoskeleton.

What is the main use of amino acids during fasting?

To synthesize ATP and glucose.

Which vitamins are stored in the liver?

Fat-soluble vitamins A, D, E, K, and vitamin B12.

Where is iron stored and for what purpose?

In the liver for future use in erythropoiesis.

How does the liver metabolize alcohol?

It converts alcohol to acetaldehyde.

How does the liver help eliminate steroid hormones and drugs?

By converting them to water-soluble forms for excretion via the kidneys and bile.

What pigment is excreted by the liver into bile as part of red blood cell breakdown?

Bilirubin.

What type of organ is the gallbladder and what does it do?

It is an intraperitoneal organ that stores and concentrates bile.

What is the storage capacity of the gallbladder?

30–60 mL.

Describe the path of bile from the liver to the duodenum.

Liver → Right/Left hepatic ducts → Common hepatic duct → Cystic duct (from gallbladder) → Common bile duct → Duodenum.

What are the components of bile?

Water, bile salts, cholesterol, bilirubin, and ions.

What are the two major functions of bile?

Emulsification of fats (digestive) and excretion of bilirubin (excretory).

What percentage of bile salts are reabsorbed and recycled?

About 90%, in the ileum.

What stimulates the release of CCK and what does it do?

Fatty chyme in the duodenum; CCK causes gallbladder contraction and relaxation of the hepatopancreatic sphincter (sphincter of Oddi).

What happens when the duodenum is empty (no CCK release)?

The hepatopancreatic sphincter closes, bile backs up, and the gallbladder fills.

Where does RBC phagocytosis occur?

In macrophages of the spleen, liver, or red bone marrow.

What is the lifespan of a red blood cell?

Approximately 120 days.

What happens to heme after RBC breakdown?

It’s converted to biliverdin, then to bilirubin.

How is iron transported after RBC breakdown?

Iron (Fe³⁺) is bound to transferrin.

What happens to globin from hemoglobin?

It is broken down into amino acids for reuse.

What two substances stimulate erythropoiesis?

Vitamin B12 and erythropoietin.

What is unconjugated bilirubin and how is it transported?

It’s lipid-soluble and transported bound to albumin.

What is conjugated bilirubin and where is it excreted?

It’s water-soluble and excreted in bile and urine.

How is bilirubin processed in the intestines?

Converted by bacteria into urobilinogen, which becomes stercobilin (feces) or urobilin (urine).

What causes jaundice?

Accumulation of bilirubin in plasma due to impaired liver function, bile flow obstruction, or excessive RBC destruction.

List some causes of pathological jaundice.

Hepatitis, liver disease, paracetamol overdose, gallstones, tumors, hemolytic anemia.

Which of the following statements regarding liver anatomy is CORRECT?

The falciform ligament is located between the right and left lobes of the liver

When glycogen stores have been exhausted, hepatocytes will:

switch to beta-oxidation, using fatty acids to generate ATP

Following a carbohydrate-rich meal:

Hepatocytes synthesize glycogen through the process of glycogenesis

Which of the following statements regarding bile is CORRECT?

CORRECT - A significant percentage of bile salts within the excreted bile is reabsorbed in the ileum

TRUE OR FALSE: The liver is attached to the diaphragm.

TRUE

TRUE OR FALSE: In the liver, sinusoids refer to the branches of blood vessels within lobules providing either oxygen rich and nutrient rich blood to hepatocytes

TRUE

Which of these provide blood supply to the liver (select all that apply)

Portal vein and hepatic artery

What drains blood from the liver

Hepatic vein - Drains blood from the liver into the inferior vena cava and Bile duct - Carries bile from the liver to the gallbladder or duodenum

Which of these are functions of the liver

Metabolism of carbohydrates, proteins, and lipids
Production of plasma proteins
Production of coagulation factors

Which of the following best describes the functions of the bile:

Bile emulsifies fats, aiding in fat digestion and absorption in the small intestine

What is the main source of bilirubin in the body, and what happens if it accumulates in the blood?

Bilirubin is a breakdown product of red blood cells, and its accumulation can cause jaundice