GI

Question 1

Malabsorption syndromes (5)

Answer 1

1. Celiace dz
   
   1. villous atrophy/flat-blunting of villi
   2. crypt hyperplasia
   3. intraepithelial lymphocyte infiltration
   4. dermatitis herpetiformis
2. disaccharidase deficiency
   
   1. NML villi
   2. osmotic diarrhea
3. pancreatic insufficiency
   
   1. d-xylose absorption test: nml
   2. d/t CF, obstructing ca, chronic pancreatitis
4. tropical sprue
   
   1. responds to AB
   2. visitor to the tropics!!!
5. whipple dz
   
   1. PAS +
   2. CAN:
      
      1. cardiac symptoms
      2. arthralgias
      3. neuro s/s

Question 2

three phases of the stimulation of acid secretion in tummy

Answer 2

1. cephalic-cholinergic and vagal
2. gastric-
3. intestinal

Question 3

Physio of acute viral hepatitis

Answer 3

• acute viral hep causes hepatocyte APOPTOSIS and NECROSIS
• APOPTOTIC hepatocytes do the following:
  
  • shrink
  • undergo nuclear fragmentation
  • become intensely EOS-inophilic
• APOPTOTIC hepatocytes…bodybodybody rockin everywhere
  
  • aka ACIDOPHILIC BODIES
  • aka COUNCILMAN BODIES
  • aka APOPTOTIC BODIES

Question 4

Tropheryma whippelii classic histo

Answer 4

• small intestine mucosa w/ enlarged, foamy macrophages
• mac packed with BOTH:
  
  • rod-shaped bacilli
  • PAS (+), diastase-resistant granules
    
    • (granules consist of lysosomes and partially digested bacteria)

Question 5

Whats up with amino-salicylic acid derivs?

Answer 5

use them to treat UC!!!

Question 6

ZES CP

Answer 6

• distal duodenal ulcer
• high-nml gastrin levels that rise in resp to secretin admin
• also: multuple ulcers and ulcers refractory to therapy
  
  • also also: diarrhea, b/c pancreatic/intestinal enzymes are inactivated by gastric acid=cant digest nutrients properly
• cause: gastrin-secreting tumors (gastrinomas)
  
  • often malig
  • location: small intestine or pancreas
• gastrin:
  
  • causes parietal cell hyperplasia
  • stim gastric acid secretion=peptic ulcers + heartburn

Question 7

proximal duodenal ulcers vs. ulcers beyond the duodenal bulb

Answer 7

• most prox caused by H pylori or NSAID
• most beyond bulb: ZES

Question 8

acute appendicitis termed

Answer 8

• periumbilical (visceral) pain that migrates to the RLQ
• NVDF
• first event in pathogenesis: OBSTRUCTION OF LUMEN of the appendix
  
  • caused by: fecaliths (mc), hyperplastic lymphoid follicles, foreign bodies, tumors, nematodies
  • retained mucus causes appendicular wall to distend–>impairs venous outflow=hypoxia=ischemia=bacterial invasion
  • bad stuff: necrosis of the wall with rupture…inflamm fluid and bacteral contents spill into the peritoneal cavity=peitonnitis
• peak incidence: kids 6-10, but happen in ALL age grous

Question 9

pigmented stones: brown vs. black (both assoc with acute calculous cholecystitis)

Answer 9

• brown: d/t biliary tract infections (microbes producing beta-glucuronidases)
• black: in the setting of:
  
  • chronic hemolytic anemia (sickle cell dz)
  • INC enterohepatic cycling of bilirubin (Crohn dz)

Question 10

acute acalculous cholecystitis

Answer 10

• acute inflamm of GB. SANS gall-stones
• who? CRITICALLY ILL pts (sepsis, severe burns, trauma, IC)
• prog: HIGH mortality
• PP: secondary to GB stasis and ISCHEMIA…cause inflamm of and injury to the GB wall

Question 11

acute acalculous cholecystitis CP

Answer 11

• fever, RUQ pain, Murphys (+), leukocytosis, mild LFT elevations
• PE: jaundice and plpable RUQ mass
• diagnostic study: US

Question 12

chronic cholecystitis termed

Answer 12

• PP: repeated mild attacks of acute cholecystitis
• gross: thikening of GB wall
• US: shrunken, fibrosed GB
• chronic may lead to porcelain GB, with INC r.o GB carcinoma

Question 13

Hi, my name is proximal colon…

Answer 13

water and electrolyte absorption

Question 14

Hi, my name is distal colon…

Answer 14

i store feces

Question 15

Hi, my name is ileum..

Answer 15

i absorb bile salts and Vit B12

Question 16

Hi, my name is stomach

Answer 16

I can absorb alcohol and water, but I prefer to be known for digestion and storage NOT absorption

Question 17

What happens in the duodenum

Answer 17

• dietary lipids (TG, phospholipids, cholesterol esters) are digested via pancreatic enzymes
• bile salts emulsify lipid breakdown products…form water-soluble micelles that facilitate lipid absorption in the jejunum

Question 18

Hirschsprung dz vs. meconium ileus

Answer 18

• HIRSCHSPRUNG
  
  • assoc with Down syndrome
  • rectosigmoid level obstruction
    
    • with a transition zone between the aganglionic rectum and proximal dilated colon
  • nml meconium consistensy
  • squirt sign (+)
    
    • INC rectal tone, causes forceful expulsion of stool after rectal exam
  • mc COD: enterocolitis (diarrhea, abdo pain/distension, fever)
• MECONIUM ILEUS
  
  • assoc with CF
  • ileum level obstruction
  • inspissated (THICK) meconium
    
    • green and inspiss=dehydrated
  • squirt sign (-)

Question 19

bowel obstruction termed

Answer 19

• abdo distension
• bilious emesis
• xray findings:
  
  • air-fluid levels
  • small bowel dilation

Question 20

What are the 5 E coli virulence factors

Answer 20

1. lipopolysaccharide (LPS)
   
   1. mech: macrophage ractivation cuases widspread release of IL-1, IL-6, and TNFalpha
   2. presentation bacermeia and septic shock
2. K1 capsular polysaccharide
   
   1. mech: prevents phagocytosis and complement-mediated lysis
   2. presentation: neonatal maningitis
3. Verotoxin (shiga-like toxin)
   
   1. mech: inactivates the 60s ribosomal compoent, halts protein synthesis and causes cell death
   2. presentation: gastroenteritis (watery)
4. heat-stable/heat-labile enterotoxins
   
   1. mech: promote fluid and electrolyte secretion from intestina epithelium
   2. presentation: gastroenteritis (watery)
5. P fimbrae
   
   1. mech: allows adhesion ot uroepithelium
   2. presentation: UTI