DIT review - GI 3 Flashcards
1
Q
Describe the function of the pancreas
A
- Fat digestion:
- Lipase, Colipase, Phospholipase A
- Protein digestion:
- Proteases (trypsin, chymotrypsin, elastase, carboxypeptidase)
- Activation of zymogens:
- Trypsinogen
- Trypsinogen is produced by the pancreas and converted to its active enzyme, trypsin, via enterokinase/enteropeptidase produced by the small intestine
- Trypsinogen
2
Q
What is the effect of CCK on the pancreas?
A
- From small intestine
- Stimulates gallbladder contraction and pancreatic secretion
3
Q
What is the effect of Secretin on the pancreas?
A
- From small intestine
- Stimulates pancreas to secrete bicarb
4
Q
Effects of cystic fibrosis on the pancreas
A
- Mutated CFTR - reduced luminal Cl- secretion and increased luminal sodium absorption (decreased water content = dehydrated, viscous mucus)
- This causes thick pancreatic secretions, causing the pancreatic ducts to get plugged
- Malabsorption of fats and proteins
- Malabsorption of fat soluble vitamins
5
Q
Causes of acute pancreatitis
A
- Autodigestion of pancreas by pancreatic enzymes
- Causes:
- Most common:
- Gallstones
- Alcohol
- I GET SMASHED:
- Idiopathic, Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune disease, Scorpion sting, Hypertriglyceridemia/Hypercalcemia, ERCP, Drugs (e.g. Sulfa, NRTIs, protease inhibitors)
- Most common:
6
Q
What is Trousseau Syndrome
A
- Hypercoagulability
- Venous thrombosis
- Migratory thrombophlebitis
7
Q
Tumor markers of pancreatic adenocarcinoma
A
CA19-9
CEA
8
Q
What is the portal triad
A
Hepatic artery, portal vein, bile duct
9
Q
What is the difference in blood being carried by the hepatic artery vs. portal vein
A
- Hepatic artery - carrying oxygenated blood
- Portal vein - carrying blood rich in nutrients and drugs that were absorbed in the GI tract
10
Q
Describe the metabolism of bilirubin, including the conjugating enzyme
A
- Hemoglobin broken down into heme and globin
- Heme then broken down into iron and protoporphyrin
- Protoporphyrin converted into unconjugataed bilirubin
- UCB binds to albumin to be brought to the liver
- Liver conjugates UCB into CB
- UDP glucuronyl transferase (UGT) is the enzyme in the hepatocytes that conjugates bilirubin
- CB dumped into bile canaliculi to be sent to the gallbladder
11
Q
What is the cause of physiologic jaundice of the newborn
A
- Newborn livers have low UGT activity, leading to increased UCB
12
Q
What is kernicterus
A
- Too much fat soluble UCB can deposit in the basal ganglia of the brain, leading to kernicterus
13
Q
How does phototherapy work for treatment of jaundice
A
- Phototherapy – makes UCB water soluble
14
Q
Describe Gilbert Syndrome (defect, elevated CB vs. UCB, presentation)
A
- Autosomal recessive
- Mildly low UGT activity
- Due to mutation in promoter region
- Slight elevation of UCB
- Benign and asymptomatic; slight jaundice during stress
15
Q
Describe Crigler-Najjar syndrome (defect, elevated Cb vs. UCB, presentation)
A
- Absence of UDP-GT
- Elevated UCB and jaundice
- Kernicterus is usually fatal
- Treatment:
- Phototherapy, Plasmapheresis (to remove UCB), liver transplant
16
Q
How do you differentiate Type I vs. Type II Crigler-Najjar syndrome
A
- Type I vs. Type II
- Type I is more severe
- If you give phenobarbital, it will cause decreased UCB in Type II and no change in Type I
17
Q
Describe Dubin-Johnson syndrome (defect, elevated CB vs. UCB, presentation)
A
- Deficiency of bilirubin canalicular transport protein
- Cannot transport CB from liver to bile ducts
- Black liver (due to build up of bilirubin in hepatocytes)
- Increased CB
- Clinically benign
18
Q
What are the 3 stages of alcoholic liver diseas?
A
Hepatic steatosis
Alcoholic hepatitis
Alcoholic cirrhosis
19
Q
Describe histology and lab values of alcoholic hepatitis
A
- Inflammation of liver – swollen and necrotic hepatocytes
- Mallory bodies – intracytoplasmic eosinophilic inclusions of damaged keratin filaments
- AST > ALT (THINK: A Scotch and Tonic)
20
Q
Why would you see bleeding and bruising in liver failure?
A
- Loss of coagulation factors - Coagulopathy and elevated PT and PTT
21
Q
Why would you see edema and ascites in liver failure?
A
- Loss of albumin - decreased osmotic pressure causing to fluid to leak out of vessels
22
Q
What is the cause of confusion, delirium, hypersomnia, coma, and death in liver failure?
A
- Inability to metabolize toxins (e.g. ammonia) - hepatic encephalopathy
23
Q
What is the cause of spider telengectasias is liver failure?
A
- Inability to inactivate steroids - elevated estradiol levels
- Testicular atrophy, gynecomastia
- Spider telengiectasias
- Palmar erythema
24
Q
Signs and symptoms of portal HTN
A
- Portosystemic shunts – anastomoses between portal venous system and systemic veins in order to relieve pressure
- Esophageal varices
- Caput medusae (around the umbilicus)
- Anorectal varices – hemorrhoids
- Hepatomegaly
- Splenomegaly
- Ascites
- Spontaneous bacterial peritonitis (SBP)
- Treat with diuretics or peritonitis
25
How do you treat esophageal varices
* Octreotide
* Endoscopic banding
* Propranolol or Nadolol
* TIPS procedure: Transjugular intrahepatic portosystemic shunt
26
What is the cocktail of drugs usually given to patients with cirrhosis
* Diuretics – ascites and edema
* Beta-blocker – prevention of bleeding esophageal varisces
* Vitamin K – to maximize clotting
* Lactulose – excrete ammonia
27
What is nutmeg liver and what causes it?
Nutmeg liver = backup of blood into liver
Caused by Budd Chiari or R heart failure
28
Cause and presentation of Budd Chiari syndrome
* Caused by occlusion of IVC or hepatic veins - decreased outflow of blood leaving the liver - congestive liver disease
* Presentation:
* Hepatomegaly, ascites, abdominal pain
* No JVD
* Liver congestion + JVD = R heart failure
29
What is the mechanism behind Reye Syndrome
* Hepatic encephalopathy in children treated with aspirin for a viral infection
* Aspirin metabolites decrease beta-oxidation by reversible inhibition of mitochondrial enzymes
30
What is the defect in Wilson disease and what does it cause (presentation, lab values)
* Autosomal recessive
* Mutation in hepatocyte copper-transporting ATPase (ATP7B gene)
* Inadequate copper excretion into bile and blood
* Decreased serum ceruloplasmin
* Increased urine copper
* Copper accumulation in: liver, brain, cornea, kidney, joints
* Presentation:
* Liver disease, Kayser-Fleischer rings, renal disease (Fanconi syndrome)
31
Treatment of Wilson disease
* Chelation with Penicillamine
32
Causes of hemochromatosis
* Primary:
* Recessive mutation in HFE gene - abnormal iron sensing - increased intestinal absorption
* Secondary:
* Chronic transfusion therapy
33
Lab values in hemochromatosis (ferritin, iron, TIBC, transferrin saturation)
Increase ferritin, increased total serum iron, decreased TIBC, increased transferrin saturation
34
Presentation of hemochromatosis
Classic triad:
Cirrhosis, Diabetes mellitus, Skin pigmentation
("bronze diabetes")
35
Treatment of hemochromatosis
* Phlebotomy
* Chelation with Deferoxamine
36
Cause of lung and liver disease in alpha-1-antitrypsin deficiency
* Lungs:
* Decreased a1-antitrypsin - uninhibited elastase in alveoli - decreased elastic tissue - panacinar emphysema
* Liver:
* Misfolded gene produce protein aggregates in hepatocellular endoplasmic reticulum - cirrhosis with PAS (+) globules
37
Diseases of what body systems will cause increased Alkaline phosphatase?
Liver, biliary, bone
38
What are associated risk factors for hepatic adenoma?
oral contraceptive, anabolic steroid use
39
What are associated risk factors for hepatic angiosarcoma
exposure to arsenic or vinyl chloride
40
What are associated risk factors for Hepatocellular carcinoma
* Hepatitis B
* Hepatitis C
* All associations with cirrhosis
* Hemochromatosis
* A1-antitrypsin deficiency
* Aflatoxin from Aspergillus
41
What lab value will be elevated in hepatocellular carcinoma
Elevated a-fetoprotein
