Gastrointestinal Physiopathology Week 9 - Key Terms and Definitions

What are the two branches of the common hepatic artery?

Proper hepatic artery

Gastroduodenal artery

What are the branches of the proper hepatic artery?

Right gastric artery

Left hepatic artery

Right hepatic artery

What artery does the cystic artery arise from?

Right hepatic artery

What are the two branches of the gastroduodenal artery?

Pancreaticoduodenal artery

Right gastroepiploic artery

Which lipoproteins are stored in the liver?

HDL, LDL, VLDL

What is the function of VLDL

Transports triglycerides to the tissues

What transports cholesterol to the liver?

HDL

What transports cholesterol to the tissues?

LDL

How much sugar can be stored in the liver as glycogen?

100g

What hormone causes the liver to produce glycogen?

Insulin

What is the function of sugar stored in the liver?

Provides stable blood sugar during the well fed state

What is the purpose of deamination of proteins by the liver?

Allows the amino acids (minus the amine group) to be converted to energy

What byproduct is produced by deamination in the liver?

Ammonia

Where is ammonia sent from the liver?

Kidneys

What do the kidneys do with ammonia?

Convert it into urea

What protein is synthesized in the liver?

Albumin

What is the function of albumin?

Creates oncotic pressure in blood vessels

Which vitamins are stored in the liver?

Fat soluble vitamins (A, D, E, K) and B12

Which minerals are stored in the liver?

Iron and copper

What is detoxified by the liver?

Drugs and hormones

What enzyme is used in phase 1 of liver detoxification?

cytochrome P450

What occurs in phase 1 of detoxification?

Conversion of toxins and chemicals into intermediaries of phase 2

What type of reaction occurs during phase 2 of detoxification?

Conjugation reaction

What occurs in phase 2 of detoxification?

Something is added to the intermediary that neutralizes it, making it water soluble

What is the byproduct of phase 2 of detoxification?

Free radicals

What is added to the bile ducts by epithelial cells?

A watery solution of sodium and bicarbonate

What causes epithelial cells to add the watery solution to the bile ducts?

Secretin

What relaxes when the walls of the duodenum contract?

The sphincter of oddi

What is the most potent stimulus of duodenal contraction?

CCK

What pathology of the liver is among the top 10 causes of death?

Cirrhosis

What is the biggest contributing factor of cirrhosis?

alcohol intake

What is the name of the bands of fibrous scars linking portal tracts in cirrhosis?

Bridging fibrous septae

What causes parenchymal nodules in cirrhotic livers?

Inflammation/injury and fibrosis

What are the 3 visual findings of a cirrhotic liver?

Smaller

Dark brown

Nodular

What % of Cirrhosis is caused by alcoholic liver disease?

60-70%

What % of cirrhosis is caused by viral hepatitis?

10%

What % of cirrhosis is caused by biliary disease?

5-10%

What % of cirrhosis is caused by cryptogenic cirrhosis?

10-15%

What % of cirrhosis is caused by Primary hemochromatosis?

5%

What % of cirrhosis is caused by Wilson disease?

Rare

What % of cirrhosis is caused by Alpha-antitrypsin deficiency?

rare

What is the cause of Biliary disease?

Blocked bile duct

What is cryptogenic cirrhosis?

Steatohepatitis (fatty liver)

What is primary hematochromatosis?

The liver stores too much iron

What occurs in the liver during Wilson disease?

The liver stores too much copper

What is the pathophysiology of fibrosis of the liver?

progressive fibrosis and reorganization of the vascular architecture

What type of collagen is normally in the space of Disse?

Type IV collagen

What type of collagen is deposited in the space of Disse in cirrhosis?

Type I and III

What deposits collagen in the space of Disse in cirrhosis?

Stellate cells

Where is blood shunted in Cirrhosis?

around the parenchyma

What happens to sinusoidal endothelial cells due to continued fibrosis in cirrhosis?

Loss of fenestration

T or F: exchange between plasma and hepatocytes remains in tract in cirrhosis?

False (it is lost)

What happens to the resistance of blood plasma traveling through sinusoids in cirrhosis?

It is increased

What protein is created in the liver and is decreased in cirrhosis?

Albumin

What are the consequences of albumin decrease in cirrhosis?

Edema and Ascites

What is ascites?

Fluid buildup in the abdominal cavity

What causes the spherical nodules confined within fibrous septa in cirrhosis?

Hepatocyte regeneration and proliferation

What is the term for resistance of portal blood flow?

Portal hypertension

What is the most common form of portal hypertension?

Intrahepatic

Which form of portal hypertension is caused by an obstructive thrombosis and narrowing of the portal vein?

Prehepatic

What can cause excessive shunting of blood into the splenic vein?

Splenomegaly

What form of portal hypertension can be caused by splenomegaly?

Prehepatic

What are the potential causes of post hepatic hypertension?

right-sided heart failure

constrictive pericardititis

hepatic vein outflow obstruction

What is the cause of intrahepatic portal hypertension?

Cirrhosis

What are the 4 major consquences of portal hypertension?

Ascites

Formation of portosystemic venous shunts

Congestive splenomegaly

Hepatic encephalopathy

What are 3 porto-systemic venous shunts?

Esophageal varices

Hemorrhoids

periumbilical varicosities (caput medusa)

T or F: Portal hypertension can be caused by an enlarged spleen, and an enlarged spleen can cause portal hypertension

True

What is the term for yellow discolouration of the skin and sclera (icterus) due to retention of pigmented bilirubin?

Jaundice

What is the term for yellowing of the sclera?

Icterus

Where is bilirubin derived from?

Heme

What oxidizes bilirubin?

Heme oxygenase

What is the product of oxygenation of bilirubin?

Biliverdin

What reduces biliverdin to unconjugated bilirubin?

Biliverdin reductase

What does bilirubin travel on in the bloodstream?

Serum albumin

What does bilirubin conjugate with in the liver to become more water soluble?

Glucuronic acid

What happens to the conjugated bilirubin produced in the liver?

It is excreted from the liver into the biliary duct as part of the bile

What converts bilirubin into urobilinogen?

Intestinal bacteria

What is the pigment that makes poop brown?

Stercobilin

What is urobilinogen converted to in the the intestinal tract?

Stercobilinogen

What is stercobilinogen oxidized into?

Stercobilin

What is stercobilin converted to into the kidneys?

Urobilin

What is the pigment that makes pee yellow?

Urobilin

Where is stercobilin converted to urobilin?

Kindeys

What are the two pathways of urobilinogen?

Absorbed in the blood or stays in the small intestine

What is the normal level of serum bilirubin?

0.3-1.2 mg/dl

At what level of serum bilirubin does jaundice become evident?

2-2.5 mg/dl

What is a complication of bilirubin getting into the brain in infants?

Neurological deficits

Name the 5 mechanisms that can cause Jaundice

Excessive production of bilirubin

Reduced hepatocyte uptake

Impaired conjugation

Decreased hepatocellular excretion

Impaired bile flow

What can cause an excessive production of bilirubin?

Bloodborne disease (e.g. malaria)

What can cause decreased hepatocyte uptake of bilirubin?

Cirrhosis

T or F: Hepatitis A is benign

True

What is the incubation period of Hepatitis A?

2-6 weeks

What type of virus is Hepatitis A?

Single-stranded

RNA

Picronavirus

What is the method of transmission of Hepatitis A?

Fecal-oral

At what times is hepatitis A infectious?

2-3 weeks before and 1 week after jaundice

What are the potential forms of hepatitis B?

Acute hepatitis with resolution (MC)

Hepatitis which goes to cirrhosis

Fulminant hepatitis with massive liver necrosis

Can lead to hepatitis D

What is the incubation period of hepatitis B?

4-26 weeks

What is the only body fluid hepatitis B is NOT found in?

Feces

What type of virus is hepatitis B?

DNA virus

What is the most common blood-borne infection?

Hepatitis C