GI Final Review

Question 1

What factor raises the mortality risk with acute hepatitis E infection?

Answer 1

Third trimester pregnancy

HEV transmitted via contaminated food/water, blood, MTC

Question 2

It is found that a patient has a sessile adenocarcinoma in the cecum. Molecular analysis of tumor demonstrates microsatellite instability. Immunostanding would likely review an absence of:
A. DNA mismatch repair protein.
B. Regulator of cell cycle.
C. Receptor tyrosine kinase
D. Small GTP binding proteins.
E. Transcriptional regulator.

Answer 2

A. DNA mismatch repair protein.

Colon cancer due to microsatellite instability = HNPCC/Lynch Syndrome (autosomal DOM)

Question 3

Laparoscopic exploration of a patient reveals a smooth liver with normal morphologic features, but a grossly black appearance. What deficiency caused this?

Answer 3

MRP2 - mediates ATP-dependent transport of organic anions across the membrane of hepatocytes, as well as exports conjugated bilirubin into bile —> pigment not secreted from the hepatocyte is stored in the lysosome and causes black color

DX = Dubin Johnson syndrome: autosomal recessive disorder caused by mutation in ABCC2 Gene, which encodes glycoprotein called multi drug resistant protein 2 (MRP2)

Question 4

74-year-old patient presents with acute onset of RUQ pain that is severe and constant. No past surgical history or travel. 102 fever. Scleral icterus is noted. Significant tenderness in the RUQ to both percussion and palpation. Ultrasound shows dilation of the common bile duct. Diagnosis?
A. Acute, viral hepatitis.
B. Acute cholecystitis.
C. Primary biliary cholangitis.
D. Acute cholangitis.
E. Acute pancreatitis.

Answer 4

D. Acute cholangitis.

A.k.a. ascending cholangitis - life-threatening condition caused by an ascending bacterial infection of the biliary tree

Classic presentation = fever + RUQ pain + jaundice

Question 5

Which of the following is a cause of bilirubin (pigment) stones?
A. Oral contraceptive pills
B. Chronic hemolysis
C. High cholesterol diet.
D. Biliary tract infection
E. Dyslipidemia.

Answer 5

B. Chronic hemolysis

A/B/E others are associated with cholesterol stones

Biliary tract infections cause brown stones (not black)

Question 6

Which of the following is consistent of biopsy of a patient with Zollinger Ellison syndrome?
A. Neutrophilic infiltration.
B. Parietal gland, hyperplasia.
C. Atrophic gastritis
D. MALToma
E. G cell hyperplasia.

Answer 6

B. Parietal gland hyperplasia - due to increase in gastrin secretion

Question 7

41-year-old woman presents with debilitating fatigue and pruritus worsening over the past six months. Labs show normal liver function tests, except for markedly elevated alkaline phosphatase, an abnormal GGTP, and elevated cholesterol. Additional testing would likely demonstrate an increase in:
A. Anticardiolipin antibodies
B. Anti smooth muscle antibodies.
C. P – ANCA titers
D. Anti-mitochondrial antibodies.
E. Alpha-fetoprotein.

Answer 7

D. Anti-mitochondrial antibodies.

Dx = primary biliary cholangitis

Fatigue + itching are primary complaints

Question 8

In which of the following is consistent with VIPoma?
A. Low gastric pH (<2)
B. Hypocalcemia
C. Enhanced glycogenolysis.
D. Hypokalemia.
E. Hypoglycemia.

Answer 8

D. Hypokalemia.

VIP is a potent stimulator of cAMP production and inhibitor of gastric acid secretion, promotes vasodilation/glycogenolysis/lipolysis/bone resorption

Secondary effects include huge secretion of water and electrolytes from the G.I. epithelial cells, hypokalemia, facial flushing, decreased gastric acidity, elevated blood glucose, and hypercalcemia

Question 9

Mutation in which of the following is most likely to cause pancreatic cancer?
A. Small GTP binding protein.
B. Receptor, tyrosine kinase.
C. Serine threonine kinase
D. DNA mismatch repair gene
E. Cell – cell adhesion molecule

Answer 9

A. Small GTP binding protein.

Most frequently mutated is KRAS —> constitutive activation of ras, a small GTP binding protein that activates MAPK and PI3K/AKT pathways

other mutations include SMAD4 and p53

Question 10

What is the most sensitive and specific indirect test of pancreatic function?

Answer 10

Fecal elastase - decreased when there is pancreatic insufficiency

Question 11

57 year old patient with 15 year history of DM2. Presents with nausea, bloating, and early satiety. evaluation reveals delayed gastric emptying. What can be given as an appropriate therapeutic strategy for this patient to increase smooth muscle contractility and peristalsis?

Answer 11

Acetylcholine

Question 12

MOA natalizumab

Answer 12

Monoclonal antibody that targets alpha4 integrin receptors on endothelial cells lining blood vessels

Decreases inflammation by blocking leukocytes migration

Question 13

MOA lubiprostone

Answer 13

Chloride channel activator, leading to water and chloride secretion in to the stool and softer stool consistency

Helps relieve constipation

Question 14

19 year old patient visits physician because his eyes look yellow in the morning. He feels well and is active in sports. No PMH. Minimal scleral icterus, normal heart sounds, no JVD, no hepatomegaly or splenomegaly. Lab analysis demonstrates total bilirubin of 3, and direct fraction of 0.1. Hepatitis B surface antigen is negative. Diagnosis?

Answer 14

Gilbert syndrome - elevated unconjugated bilirubin with no other symptoms

Onset occurs later in life (not at birth)

Question 15

A rise in serum direct bilirubin would be expected in:
A. Physiological jaundice
B. Gilbert syndrome.
C. Crigler Najjar syndrome.
D. Dubin Johnson syndrome.
E. Hemolytic, anemia.

Answer 15

D. Dubin Johnson syndrome - decreased activity of MRP2 (transporter that exports conjugated bilirubin)

All others have reduced or total deficiency in the bilirubin UDP-glucoronyl transferase activity, which is important for conjugation of bilirubin to become direct bilirubin

Question 16

Elevated conjugated bilirubin + near normal unconjugated bilirubin + absence of fecal stercobilin in a jaundiced patient =
A. Cholestasis.
B. Hemolytic, anemia.
C. Absence of bilirubin, UDP-glucoronyl transferase
D. Gilbert syndrome.

Answer 16

A. Cholestasis.

Absence of fecal urobilin indicates an obstruction of the biliary tract by gallstones, leading to cholestasis

Question 17

A patient with a defect in the urea cycle can still temporarily detoxify ammonia through…

Answer 17

Amidation of glutamate to yield glutamine

Question 18

High blood methionine concentration = deficiency in what enzyme?

Answer 18

Cystathionine b-synthase

Question 19

Newborn with elevated ammonium, glutamine, and alanine, but orotic acid and citrulline are not elevated. Which enzyme is defective?

Answer 19

Carbamoyl phosphate synthetase 1 (CPS-1)

Question 20

Function of colipase?

Answer 20

Helps pancreatic lipase bind to the oil-water interface of lipids

Question 21

What is the product normally formed by the enzyme adenosine deaminase?

Answer 21

ADA deaminates adenosine to form inosine

[ADA deficiency is one form of severe combined immunodeficiency]

Question 22

Which two sugars compete for transportation via SGLT1?

Answer 22

Glucose and galactose

Question 23

Which amino acid is present in the highest concentration in the serum?

Answer 23

Glutamine – plays special roles in the transport of amino groups from non-hepatic tissues to the liver

Question 24

Lactase is:
A. Intraluminal enzyme.
B. Brush border enzyme.
C. Apical transporter.

Answer 24

B. Brush border enzyme.

Question 25

Someone with lactose intolerance would have increased or decreased hydrogen on a lactose hydrogen breath test?

Answer 25

Increased hydrogen due to undigested lactose that is being acted upon by bacteria to produce hydrogen in the large intestine

Question 26

Which of the following is true of internal hemorrhoids?
A. Receive somatic innervation.
B. Form portosystemic anastomosis.
C. Receive blood from the superior mesenteric artery.
D. Covered with columnar epithelium.

Answer 26

D. Covered with columnar epithelium.

Internal hemorrhoids are above the dentate line, do not receive somatic innervation, and are covered with columnar epithelium. Vascular supply by the superior, middle and inferior hemorrhoidal arteries. Venous drainage via the inferior and middle hemorrhoidal veins, which ultimately drain into the iliac veins.

Question 27

Which of the following is expected in a patient with anal fissures?
A. Internal sphincter muscle spasm.
B. High-grade squamous dysplasia.
C. Crypto, glandular infection
D. Hemorrhoidal cushion hypertrophy

Answer 27

A. Internal sphincter muscle spasm.

Initiating factor of anal fissures is thought to be trauma from the passage of a particularly hard or painful bowel movement - patients with underlying abnormalities of the internal sphincter are at higher risk for anal fissures

Question 28

Which of the following is typical of diffuse type gastric cancer?
A. Loss of e-cadherin
B. Activation of c-kit
C. Loss of p53

Answer 28

A. Loss of e-cadherin

Question 29

65-year-old patient presents with persistent, epigastric pain accompanied by anorexia and early satiety. Upper endoscopy demonstrates thickened gastric folds, and rapid urease test is positive. Biopsy shows diffuse involvement of the mucosa and submucosa. Further testing of these cells is likely to demonstrate:
A. Loss of e-Cadherin
B. Positive CD 20 expression.
C. Anti-parietal cell antibodies.
D. Intestinal metaplasia.
E. Mucosal cell hypertrophy.

Answer 29

B. Positive CD20 expression.

Helicobacter pylori is associated with a dense lymphoplasmacytic infiltration of the gastric lymphoma, which can lead to lymphoma of the MALT type

Question 30

A patient with gastric atrophy would likely also have:
A. Microcytic, anemia.
B. Low gastrin levels.
C. Anti-parietal cell antibodies.
D. D cell hyperplasia.

Answer 30

C. Anti-parietal cell antibodies.

Dx = auto immune gastritis - destruction of parietal glands by T cells and formation of antibodies against parietal cells, components and intrinsic factor leading to B12 deficiency (macrocytic, anemia)

Gastrin levels would be high due to lack of negative inhibition, D cells produce somatostatin which would be low

Question 31

67 year old patient presents with acute onset of odynophagia that began this morning. Patient states they are barely able to swallow their own saliva due to the pain. There is also mild substernal chest pain. No vomiting, bleeding, recent, weight, loss, or fatigue. She recently began a new medication to treat her osteoporosis. What is the likely diagnosis?

Answer 31

“Pill” esophagitis due to esophageal mucosal injury caused by direct toxic effect of medication

Question 32

47 year old presents with difficulty swallowing. Problem begins immediately with attempted swallowing. It is worse with liquids. The dysphasia is associated with regurgitation of contents into the nasopharynx and repeated episodes of coughing. The problem typically begins about midway through the meal. This is most consistent with:
A. Zenker diverticulum
B. Myasthenia gravis.
C. Esophageal web.
D. Schatzki ring.
E. Esophageal stricture

Answer 32

B. Myasthenia gravis.

Oropharyngeal dysphasia that is worse with liquids indicates a motor or propulsive problem

All other options are esophageal type dysphasia

Question 33

Chagas is a cause of _____, which will lead to dysphasia and “birds beak” sign on imaging

Answer 33

achalasia: hypertensive lower esophageal sphincter (LES) and loss of esophageal peristalsis

Question 34

44-year-old presents with episodes of dysphasia for both solids and liquids. Problem occurs after he has initiated swallowing and feels as though food is not going down properly. There is associated substernal chest pressure. Dysphasia is intermittent, between episodes he is asymptomatic. No history of heartburn. PE is normal. This histories most consistent with a diagnosis of:
A. Zenker’s diverticulum.
B. Esophageal stricture
C. Esophageal cancer.
D. Achalasia.
E. Diffuse esophageal spasm.

Answer 34

E. Diffuse esophageal spasm.

Description is of esophageal dysphasia - trouble with liquids and solids from the outset, suggesting a motility problem

[Zenkers diverticulum is a motor problem, but the symptoms are progressive and constant wants the disease as apparent (does not go away between episodes)]

Question 35

What is the initial management for a patient with small bowel obstruction?

Answer 35

Fluid resuscitation

Question 36

A patient presenting with lower bowel obstruction should most raise concern for:
A. Adhesions.
B. Ovarian cancer.
C. Intussusception
D. Colorectal cancer.

Answer 36

D. Colorectal cancer - number one cause of lower bowel obstruction

Question 37

Pneumatosis intestinalis in an infant raises concern for…

Answer 37

Necrotizing enterocolitis - almost exclusively effects neonates, especially those that are premature

Due to inflammation of the intestinal epithelium, leading to barrier failure and bacterial invasion, causing necrosis of the colon and intestines

Question 38

What kind of kidney stones are caused by Crohn’s disease?

Answer 38

Calcium oxalate - due to malabsorption of fatty acids and bile salts, which leads to an increase in oxalate absorption and subsequent excretion

Question 39

Which of the following is a dermatologic manifestation of Crohn’s disease?
A. Erysipelas
B. Erythema multiforme.
C. Pyoderma gangrenosum.
D. Dermatitis herpetiformis.
E. Erythema nodosum

Answer 39

E. Erythema nodosum - delete a type hypersensitivity, may involve immune complex deposition in the septal venules of the subcutaneous fat

Question 40

Mesothelial cells =
A. Neural crest.
B. Ectoderm.
C. Visceral mesoderm
D. Endoderm.
E. Parietal mesoderm

Answer 40

E. Parietal mesoderm

Question 41

How to distinguish jejunum from ileum

Answer 41

Jejunum has more mucosal – submucosal folds (known as place circular), and a mesentery with less fat and containing few long arcades with long vasa recta

Ileum has mesentery with more fat and short arcades

Question 42

What do the granules of Paneth cells contain?

Answer 42

Enzymes (lysozyme) capable of hydrolyzing bacterial cell walls

Question 43

Ligation of the gastroduodenal artery would result in retrograde flow in which artery?

Answer 43

Right Gastro-omental artery - branch of the gastroduodenal artery

(Left Gastro omental artery is a branch of the splenic artery)

The right and left Gastro omental arteries anastomose

Question 44

Which parts of the gut receive parasympathetic supply from the vagus nerve versus the pelvic splanchnic nerves?

Answer 44

Vagus nerve – foregut and midgut

Pelvic splanchnic nerves – hindgut

Question 45

Pulsatile bleeding from a vessel in the first part of the duodenum is due to bleeding of a vessel that is a branch of the…

Answer 45

Common hepatic artery – divides into proper hepatic and gastroduodenal artery, which supplies the first portion of the duodenum