Liver And Biliary System

Question 1

The Liver and the Biliary System Study Questions
1. What are some of the principal functions of the liver? How does the blood supply to the liver differ from that to other organs? Why does severe liver disease cause disturbances in blood clotting?
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How does the blood supply to the liver differ from that to other organs?

Answer 1

The Hepatic Portal
A system of veins comprising the hepatic portal vein and its tributaries.
Responsible for directing blood from parts of the gastrointestinal (GI) tract to the liver. Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart.
(Many drugs that are absorbed through the GI tract are substantially metabolized by the liver before reaching general circulation.)

Blood flow to the liver is unique in that it receives both oxygenated and (partially) deoxygenated blood.
Blood passes from branches of the portal vein through cavities between “plates” of hepatocytes called sinusoids.
Blood also flows from branches of the hepatic artery and mixes in the sinusoids to supply the hepatocytes with oxygen.
This mixture percolates through the sinusoids . A liver sinusoid is a type of sinusoidal blood vessel (with fenestrated, discontinuous endothelium) that serves as a location for the oxygen-rich blood from the hepatic artery and the nutrient-rich blood from the portal vein. Hepatocytes are separated from the sinusoids by the space of Disse. Kupffer cells are located inside the sinusoids and can take up and destroy foreign material such as bacteria. This blood then collects in a central vein which drains into the hepatic vein. The hepatic vein subsequently drains into the inferior vena cava. The hepatic artery provides 30 to 40% of the oxygen to the liver, while only accounting for 25% of the total liver blood flow. The rest comes from the partially deoxygenated blood from the portal vein. Interestingly, the liver consumes about 20% of the total body oxygen when at rest. That is why the total liver blood flow is quite high, at about 1 liter a minute and up to two liters a minute. That is on average one-fourth of the average cardiac output at rest.

Question 2

The Liver and the Biliary System Study Questions
1. What are some of the principal functions of the liver? How does the blood supply to the liver differ from that to other organs? Why does severe liver disease cause disturbances in blood clotting?
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Why does severe liver disease cause disturbances in blood clotting?

Answer 2

The liver makes necessary proteins for the body. This function is called the liver’s “synthetic function.” Many patients with liver disease have normal synthetic function until disease is very bad. The liver makes coagulation factors, proteins that help the blood to clot. This protects us from bleeding. When the liver is failing, it cannot make clotting factors. A blood test that measures blood clotting is called PT/PTT or pro-time (sometimes also referred to as INR). When the liver cannot make clotting factors, the pro-time is abnormally high. Another protein that the liver makes is called albumin. This small protein helps to keep fluid in the bloodstream and prevents swelling or accumulation of fluid outside the blood vessels of the body. When the liver does not work well, the albumin is low. Other conditions, such as malnutrition or loss of albumin in the stool or urine, can also make the albumin be low.

Question 3

2. ## What is the difference between hemoglobin and bilirubin? How does conjugated bilirubin differ from unconjugated bilirubin? What is the difference between bilirubin and bile? What role does bile play in digestion?What is the difference between hemoglobin and bilirubin?

Answer 3

Bilirubin is a byproduct of destruction of aged red blood cells. It gives bile a greenish black color and produces the yellow tinge of jaundice.

Hemoglobin is the protein molecule in red blood cells that carries oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs. Hemoglobin is made up of four protein molecules (globulin chains) that are connected together.

Question 4

2. ## What is the difference between hemoglobin and bilirubin? How does conjugated bilirubin differ from unconjugated bilirubin? What is the difference between bilirubin and bile? What role does bile play in digestion?How does conjugated bilirubin differ from unconjugated bilirubin?

Answer 4

Conjugated bilirubin is water soluable and transforms bilirubin from a lipid-soluable substance that can cross biological membranes to a water soluable substance that is excreted in the bile.

Unconjugated bilirubin is lipid soluable.

Question 5

2. ## What is the difference between hemoglobin and bilirubin? How does conjugated bilirubin differ from unconjugated bilirubin? What is the difference between bilirubin and bile? What role does bile play in digestion?What is the difference between bilirubin and bile?

Answer 5

Bilirubin is a byproduct of destruction of aged red blood cells. It gives bile a greenish black color and produces the yellow tinge of jaundice.

Bile is an alkaline, bitter tasting, yellow-greenish fluid that contains bile salts, cholesterol and bilirubin, electrolytes and water.

Question 6

2. ## What is the difference between hemoglobin and bilirubin? How does conjugated bilirubin differ from unconjugated bilirubin? What is the difference between bilirubin and bile? What role does bile play in digestion?What role does bile play in digestion?

Answer 6

Bile contains bile acids, which are critical for digestion and absorption of fats and fat-soluble vitamins in the small intestine. Many waste products, including bilirubin, are eliminated from the body by secretion into bile and elimination in feces

Question 7

3. ## What are the possible causes and effects of liver injury? What is the usual outcome of a liver injury?What are the possible causes and effects of liver injury?

Answer 7

The liver can be damaged as a result of impact (for example, a motor vehicle crash) or penetrating trauma (such as a knife or gunshot wound). Injuries may range from relatively small collections of blood (hematomas) within the liver to large tears that go deep into the liver. Because the liver has many large blood vessels, the main problem resulting from liver injury is severe bleeding. Nearly all bleeding from a liver injury occurs within the abdominal cavity.

Question 8

3. ## What are the possible causes and effects of liver injury? What is the usual outcome of a liver injury?What is the usual outcome of a liver injury?

Answer 8

Observation

Sometimes embolization or surgical repair

Hemodynamically stable patients who have no other indications for laparotomy (eg, hollow viscus perforation) can be observed with monitoring of vital signs and serial Hct levels. Patients with significant ongoing hemorrhage (ie, those with hypotension and shock, significant ongoing transfusion requirements, or declining Hct) require intervention. Patients whose vital signs are stable but who require ongoing transfusion may be candidates for angiography with selective embolization of bleeding vessels. Unstable patients should undergo laparotomy.

Success rates for nonoperative management are about 92% for grade 1 and 2 injuries, 80% for grade 3 injuries, 72% for grade 4 injuries, and 62% for grade 5 injuries. Following nonoperative management, patients typically may return to full activity (eg, strenuous work, sports) in about 2 to 3 mo, depending on the severity of injury.

When surgery is done, small lacerations can typically be sutured or treated with hemostatic agents (eg, oxidized cellulose, fibrin glue, mixtures of thrombin and powdered gelatin). Surgical management of deeper and more complex injuries can be complicated.

Question 9

1. ## What are some of the principal functions of the liver? How does the blood supply to the liver differ from that to other organs? Why does severe liver disease cause disturbances in blood clotting?What are some principal functions of the liver?

Answer 9

The liver is a metabolically active organ responsible for many vital life functions. The primary functions of the liver are:

Bile production and excretion
Excretion of bilirubin, cholesterol, hormones, and drugs
Metabolism of fats, proteins, and carbohydrates
Enzyme activation
Storage of glycogen, vitamins, and minerals
Synthesis of plasma proteins, such as albumin, and clotting factors
Blood detoxification and purification

Question 18

The largest organ of the body is…..

What are its functions?

Answer 18

1. The liver is the largest organ in the body. It has digestive, metabolic, hematologic, vascular, and immunologic functions.

Question 19

How many lobes does the liver have?

What ligaments support it?

Answer 19

2. The liver is divided into right and left lobes and is supported by the falciform, round, and coronary ligaments.

Question 20

Name the functional cells of the liver.

Answer 20

3. Liver lobules consist of plates of hepatocytes, which are the functional cells of the liver.

Question 21

Which artery supplies blood to the liver?

Which vein receives blood from the inferior and superior mesenteric veins?

Answer 21

4. The hepatic artery supplies blood to the liver.

The portal vein receives blood from the inferior and superior mesenteric veins.

Question 22

_____synthesize 700 to 1200 mL of bile/day and secrete it into the bile __________. These drain bile into the _____ _____ _____ and then into the _____ through an opening called the major duodenal papilla (or the sphincter of _____.)

Answer 22

5. Hepatocytes synthesize 700 to 1200 mL of bile/day and secrete it into the bile canaliculi, which are small channels between the hepatocytes. The bile canaliculi drain bile into the common bile duct and then into the duodenum through an opening called the major duodenal papilla (sphincter of Oddi).

Question 23

These cells metabolize nutrients, detoxify chemicals, secrete bile, synthesize albumin and clotting factors, and other functions.

Answer 23

Hepatocytes

Question 24

The cells remove bacteria and foreign particles from blood in the hepatic sinusoids

Answer 24

Kupffer cells

Question 25

The cells secrete digestive enzymes

Answer 25

Pancreatic acinar cells

Question 26

The cells secrete bicarbonate rich fluid

Answer 26

Pancreatic ductile epithelium

Question 27

Did gastrin and motilin stimulate or delayed gastric emptying?

Answer 27

Stimulate

Question 28

Do secretin and cholecystokinin stimulate or delay gastric emptying?

Answer 28

Delay

Question 29

Which organ produces bile?

Answer 29

Liver

Question 30

Is bile acidic or alkaline?

Answer 30

Alkaline

Question 31

True or false. The liver receives blood from both arterial and venous sources.

Answer 31

True

Question 32

Branches from the abdominal aorta and prevents oxygenated blood at a rate of 400 to 500 mL per minute.

Answer 32

Hepatic artery

Question 33

Receives deoxygenated blood from the inferior and superior mesenteric vein's in the splenic vein, delivers about 1000 to 1200 mL per minute of blood to the liver

Answer 33

Hepatic portal vein

Question 34

Carrie 70% of the blood supply to the liver.

Answer 34

The portal vein

Question 35

The blood in this vessel carries some oxygen and is rich in nutrients that have been absorbed from the digestive tract and transported through the mesenteric vein.

Answer 35

The portal vein

Question 36

Venous blood from all of the lobules of the liver flow through this vessel which empties into the inferior vina cava.

Answer 36

Hepatic vein

Question 37

4. What is viral hepatitis? What are its major symptoms? How is hepatitis transmitted? ------------ What is viral hepatitis? See breakdowns.

Answer 37

See breakdowns. Many illnesses and conditions can cause inflammation of the liver (hepatitis), but certain viruses cause about half of all hepatitis in people. Viruses that primarily attack the liver are called hepatitis viruses. There are several types of hepatitis viruses including types A, B, C, D, E, and possibly G. Types A, B, and C are the most common. All hepatitis viruses can cause acute hepatitis. Viral hepatitis types B and C can cause chronic hepatitis. Symptoms of acute viral hepatitis include fatigue, flu-like symptoms, dark urine, light-colored stools, fever, and jaundice; however, acute viral hepatitis may occur with minimal symptoms that go unrecognized. Rarely, acute viral hepatitis causes fulminant hepatic failure. The symptoms of chronic viral hepatitis often are mild and nonspecific, and the diagnosis of chronic hepatitis often is delayed. Chronic viral hepatitis often requires treatment in order to prevent progressive liver damage, cirrhosis, liver failure, and liver cancer. Hepatitis infections can be prevented by avoiding exposure to viruses, injectable immunoglobulins or by vaccines; however, there is vaccine available for only hepatitis A and B. Those at risk for viral hepatitis B and C include workers in the health care profession, people with multiple sexual partners, intravenous drug abusers, and people with hemophilia. Blood transfusion is a rare cause of viral hepatitis.

Question 38

What is hepatitis A? [HAV

Answer 38

Hepatitis A virus (HAV) is present in the faeces of infected persons and is most often transmitted through consumption of contaminated water or food. Certain sex practices can also spread HAV. Infections are in many cases mild, with most people making a full recovery and remaining immune from further HAV infections. However, HAV infections can also be severe and life threatening. Most people in areas of the world with poor sanitation have been infected with this virus. Safe and effective vaccines are available to prevent HAV.

Question 39

What are the symptoms of Hepatitis A?

Answer 39

Hepatitis A signs and symptoms, which typically don't appear until you've had the virus for a few weeks, may include: Fatigue Nausea and vomiting Abdominal pain or discomfort, especially in the area of your liver on your right side beneath your lower ribs Clay-colored bowel movements Loss of appetite Low-grade fever Dark urine Joint pain Yellowing of the skin and eyes (jaundice) If you have hepatitis A, you may have a mild illness that lasts a few weeks or a severe illness that lasts several months. Not everyone with hepatitis A develops signs or symptoms.

Question 40

How is Hepatitis A transmitted?

Answer 40

most often transmitted through consumption of contaminated water or food. Certain sex practices can also spread HAV.

Question 41

What is Hepatitis B?

Answer 41

Hepatitis B infection is caused by the hepatitis B virus (HBV). The virus is passed from person to person through blood, semen or other body fluids. Hepatitis B infection may be either short-lived (acute) or long lasting (chronic). Acute hepatitis B infection lasts less than six months. Your immune system likely can clear acute hepatitis B from your body, and you should recover completely within a few months. Most people who acquire hepatitis B as adults have an acute infection, but it can lead to chronic infection. Chronic hepatitis B infection lasts six months or longer. When your immune system can't fight off the acute infection, hepatitis B infection may last a lifetime, possibly leading to serious illnesses such as cirrhosis and liver cancer. The younger you are when you get hepatitis B — particularly newborns or children younger than 5 — the higher your risk the infection becoming chronic. Chronic infection may go undetected for decades until a person becomes seriously ill from liver disease.

Question 42

How is Hepatitis B transmitted?

Answer 42

Hepatitis B virus (HBV) is transmitted through exposure to infective blood, semen, and other body fluids. HBV can be transmitted from infected mothers to infants at the time of birth or from family member to infant in early childhood. Transmission may also occur through transfusions of HBV-contaminated blood and blood products, contaminated injections during medical procedures, and through injection drug use. HBV also poses a risk to healthcare workers who sustain accidental needle stick injuries while caring for infected-HBV patients. Safe and effective vaccines are available to prevent HBV.

Question 43

What are the symptoms of hepatitis B?

Answer 43

Signs and symptoms of hepatitis B, ranging from mild to severe, usually appear about one to four months after you've been infected. Signs and symptoms of hepatitis B may include: ``` Abdominal pain Dark urine Fever Joint pain Loss of appetite Nausea and vomiting Weakness and fatigue Yellowing of your skin and the whites of your eyes (jaundice) ```

Question 44

What is Hepatitis C?

Answer 44

Hepatitis C is a contagious liver disease that ranges in severity from a mild illness lasting a few weeks to a serious, lifelong illness that attacks the liver. It results from infection with the Hepatitis C virus (HCV), which is spread primarily through contact with the blood of an infected person. Hepatitis C can be either “acute” or “chronic.” Acute Hepatitis C virus infection is a short-term illness that occurs within the first 6 months after someone is exposed to the Hepatitis C virus. For most people, acute infection leads to chronic infection. Chronic Hepatitis C virus infection is a long-term illness that occurs when the Hepatitis C virus remains in a person’s body. Hepatitis C virus infection can last a lifetime and lead to serious liver problems, including cirrhosis (scarring of the liver) or liver cancer.

Question 45

How is hepatitis C transmitted?

Answer 45

Hepatitis C is usually spread when blood from a person infected with the Hepatitis C virus enters the body of someone who is not infected. Today, most people become infected with the Hepatitis C virus by sharing needles or other equipment to inject drugs. Before 1992, when widespread screening of the blood supply began in the United States, Hepatitis C was also commonly spread through blood transfusions and organ transplants. People can become infected with the Hepatitis C virus during such activities as Sharing needles, syringes, or other equipment to inject drugs Needlestick injuries in health care settings Being born to a mother who has Hepatitis C Less commonly, a person can also get Hepatitis C virus infection through Sharing personal care items that may have come in contact with another person’s blood, such as razors or toothbrushes Having sexual contact with a person infected with the Hepatitis C virus

Question 46

What are the symptoms of Hepatitis C?

Answer 46

``` Approximately 70%–80% of people with acute Hepatitis C do not have any symptoms. Some people, however, can have mild to severe symptoms soon after being infected, including: Fever Fatigue Loss of appetite Nausea Vomiting Abdominal pain Dark urine Clay-colored bowel movements Joint pain Jaundice (yellow color in the skin or eyes) ```

Question 47

What is hepatitis D?

Answer 47

Hepatitis D, also known as "delta hepatitis," is a liver infection caused by the Hepatitis D virus (HDV). Hepatitis D is uncommon in the United States. Hepatitis D only occurs among people who are infected with the Hepatitis B virus because HDV is an incomplete virus that requires the helper function of HBV to replicate. HDV can be an acute, short-term, infection or a long-term, chronic infection. Hepatitis D is transmitted through percutaneous or mucosal contact with infectious blood and can be acquired either as a coinfection with HBV or as superinfection in people with HBV infection. There is no vaccine for Hepatitis D, but it can be prevented in persons who are not already HBV-infected by Hepatitis B vaccination.

Question 48

What is hepatitis E?

Answer 48

What is Hepatitis E? Hepatitis E is a liver disease caused by the Hepatitis E virus (HEV). HEV infection usually results in a self-limited, acute illness. It is widespread in the developing world. Although rare in developed countries, locally acquired HEV infection can result in acute hepatitis with tendency to progress to chronic hepatitis mainly among solid organ transplant recipients.

Question 49

What is anicteric hepatitis ?

Answer 49

Hepatitis without jaundice.

Question 50

What is subclinical hepatitis?

Answer 50

Patients with inapparent or subclinical hepatitis have neither symptoms nor jaundice. Children generally belong to this group. These asymptomatic cases can only be recognized by detecting biochemical or serologic alterations in the blood.

Question 51

What is alcoholic hepatitis?

Answer 51

Alcoholic hepatitis is inflammation of the liver caused by drinking alcohol. Alcoholic hepatitis is most likely to occur in people who drink heavily over many years. However, the relationship between drinking and alcoholic hepatitis is complex. Not all heavy drinkers develop alcoholic hepatitis, and the disease can occur in people who drink only moderately.

Question 52

What is jaundice? How is jaundice classified? Under what circumstances do gallstones cause jaundice? ------------ What is jaundice?

Answer 52

a medical condition with yellowing of the skin or whites of the eyes, arising from excess of the pigment bilirubin and typically caused by obstruction of the bile duct, by liver disease, or by excessive breakdown of red blood cells.

Question 53

What is jaundice? How is jaundice classified? Under what circumstances do gallstones cause jaundice? ------------ How is jaundice classified?

Answer 53

``` Three categories: I. Pre-hepatic/ hemolytic The pathology is occurring prior to the liver due to either: A. Intrinsic defects in RB cells B. Extrinsic causes external to RB cells ``` II. Hepatic/ hepatocellular The pathology is located within the liver caused due to disease of parenchymal cells of liver. III. Post-Hepatic/ cholestatic The pathology is located after the conjugation of bilirubin in the liver caused due to obstruction of biliary passage.

Question 54

What is jaundice? How is jaundice classified? Under what circumstances do gallstones cause jaundice? ------------ Under what circumstances do gallstones cause jaundice?

Answer 54

Jaundice develops when a stone passes from the gallbladder through the cystic duct into the bile duct and blocks the bile duct. Patients present with a yellowish discoloration of their skin associated with severe itchiness. An emergency procedure by a gastroenterologist is often required to remove the stones from the bile duct.

Question 55

What factors predispose to the development of gallstones?

Answer 55

Factors that may increase your risk of gallstones include: ``` Being female Being age 60 or older Being an American Indian Being a Mexican-American Being overweight or obese Being pregnant Eating a high-fat diet Eating a high-cholesterol diet Eating a low-fiber diet Having a family history of gallstones Having diabetes Losing weight very quickly Taking some cholesterol-lowering medications Taking medications that contain estrogen, such as hormone therapy drugs ```

Question 56

What is cirrhosis of the liver?

Answer 56

Cirrhosis is an irreversible scarring of the liver that results from inflammation, which disrupts liver structure. The disease is characterized by bands of fibrous tissue and nodular regeneration. Two of the most common causes of cirrhosis are chronic alcohol abuse and hepatitis C. Approximately 25% of individuals who consume significant amounts of alcohol develop cirrhosis, and the risk is greater in women.

Question 57

What liver diseases may lead to cirrhosis?

Answer 57

Chronic alcohol abuse Hepatitis C Hepatitis B Fat accumulating in the liver (nonalcoholic fatty liver disease) Destruction of the bile ducts (primary biliary cirrhosis) Hardening and scarring of the bile ducts (primary sclerosing cholangitis) Infection by a parasite common in developing countries (schistosomiasis) Congenital causes: Iron buildup in the body (hemochromatosis) Cystic fibrosis Copper accumulated in the liver (Wilson's disease) Poorly formed bile ducts (biliary atresia) Inherited disorders of sugar metabolism (galactosemia or glycogen storage disease) Genetic digestive disorder (Alagille syndrome) Liver disease caused by your body's immune system (autoimmune hepatitis)

Question 58

Why does portal hypertension develop in patients with cirrhosis?

Answer 58

Liver cirrhosis increases resistance to blood flow and higher pressure in the portal venous system, resulting in portal hypertension. Effects of portal hypertension include: Splenomegaly (increase in size of the spleen) is found in 35% to 50% of patients. Esophageal varices result from collateral portal blood flow through vessels in the stomach and esophagus (a process called Portacaval anastomosis). When these blood vessels become enlarged, they are called varices and are more likely to burst. Caput medusa are dilated periumbilical collateral veins due to portal hypertension. Blood from the portal venous system may be shunted through the periumbilical veins and ultimately to the abdominal wall veins, manifesting as a pattern that may resemble the head of Medusa. Cruveilhier-Baumgarten murmur is a venous hum heard in the epigastric region (on examination by stethoscope) due to collateral connections forming between portal system and the periumbilical veins as a result of portal hypertension.

Question 59

Why does ascites develop in patients with cirrhosis?

Answer 59

Accumulation of fluid in the abdominal cavity is called ascites. Ascites is common in people with cirrhosis and it usually develops when the liver is starting to fail. Ascites is caused by a combination of elevated pressure in the veins running through the liver (portal hypertension) and a decrease in liver function caused by scarring of the liver, i.e., cirrhosis.

Question 60

Why do Esophageal varices develop?

Answer 60

Esophageal varices develop when normal blood flow to the liver is obstructed by scar tissue in the liver or a clot. Seeking a way around the blockages, blood flows into smaller blood vessels that are not designed to carry large volumes of blood.