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118 Cards in this Set
- Front
- Back
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What cell types are found in the mucosa of the large intestine?
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Paneth cells
Goblet cells Basal cells Endocrine cells: 9 types |
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What is an omphalocele?
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Congenital defect of the abdominal wall causing herniation of the intestines into a membranous sac
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What is the most common congenital anomaly of the lower GIT? What causes it?
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Meckel's Diverticulum
Remnant of the omphalomesenteric duct (Vitelline) |
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What does a Meckel's look like grossly?
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5-6 cm in lenght
located 2 ft from the ileocecal valve could be free or attached to abd wall |
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What is a complication associated with Meckel's?
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Could have pancreatic and gastric tissue in it that could lead to ulceration and bleeds
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Which portion of the lower GIT is predisposed to volvulus? What term generally describes pathologic movement of the GIT?
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Malrotation, most common with the colon
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What is Hirschsprung disease?
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Megacolon due to a lack of ganglion cells in the colon wall.
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What segment develops megacolon with Hirschsprung? Which segments lack innervation?
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The upstream segments that are properly innervated
Most likely the rectum and colon and aganglionic |
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What is the clinical presentation of Hirschsprung?
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Failure to pass meconium
Constipation/Diarrhea Failure to thrive Fluid/electrolyte imbalance Enterocolitis with possible perforation |
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What more common: arterial or vein thromboses causing ischemic bowel?
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Arterial due to plaque
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What type of ischemic bowel is characteristic of hypoperfusion or shock?
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mural or mucosal infarction
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What are the predisposing factors for ischemic bowel?
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1. arterial thrombosis
2. arterial embolism 3. venous thrombosis: any hypercoag 4. nonocclusion ischemia 5. other shit: volvulus, stricture, etc |
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What is the gross appearance of a transmural infarction?
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Dark red hemorrhagic lesion that starts in the mucosa and extends outward.
Within 18-24 hours: fibrinous exudate over the serosa. |
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If you find a fibrinous exudate over the bowel, what has most likely happened?
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transmural ischemia of the bowel within the last 24 hours.
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What is the gross appearance of a mural or mucosal infarction?
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See multifocal lesions not visible from serosal surface.
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What type of bowel ischemia could mimic inflammatory bowel?
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Mural or mucosal ischemia caused by chronic vascular insufficiency
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What type of bowel ischemia must be dx quickly to save the pt?
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transmural infarction could cause vascular collapse and death
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What is angiodysplasia?
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Proliferation of small vessels in the GIT causing bleeding. Accounts for 20% of GI bleeds, but in less than 1% of population.
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What part of the GIT is more prone to angiodysplasia? Who gets this?
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cecum and right colon
mostly in pts in their 50's with systemic syndromes |
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What are common causes of hemorrhoids?
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Straining and pregos
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What is the definition of diarrhea?
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>250g/day with 70-90% water
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What is dysentery?
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low volume, painful, bloody diarrhea
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How many die per day from diarrhea in developing countries?
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12,000/day
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What is secretory diarrhea?
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intestinal fluid that is isotonic with plasma and persists with fasting
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What are infectious causes of diarrhea that damage the epithelium?
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Rotavirus and Norovirus and Enteric adenovirus
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What are infectious causes of diarrhea that mediate action via toxins?
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E. coli
V. cholerae B. cereus C. Perfringens |
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What toxin does E. coli produce to cause diarrhea?
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Shiga toxin
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Why would a tumor cause diarrhea?
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could be producing peptides or serotonin to cause secretory diarrhea
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What is the most common cause of diarrhea in US?
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Norovirus
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Why can you not culture perfringens to dx diarrhea?
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Normal gut flora, must look for enterotoxin
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What are the common causes of secretory diarrhea?
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Infectious bugs
Tumors Laxatives |
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What is osmotic diarrhea?
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Diarrhea caused by excessive osmotic forces that stops with fasting
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What causes osmotic diarrhea?
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Anything that cleans the gut out, like Lactulose or antacids
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What causes exudative diarrhea?
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Infection with bowel injury
Inflammatory bowel dz |
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What bugs should you suspect if your pt has purulent diarrhea?
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Shigella
Salmonella Campylobacter Entamoeba histolytica |
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What is malabsorptive diarrhea?
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voluminous bulky stool
steatorrhea |
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What infectious agent can cause malabsorptive diarrhea?
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Giardia lamblia
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What kind of diarrhea is caused by E. histolytica?
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exudative
Think liver abscess! |
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What are the two types of deranged motility diarrhea?
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Increased and decreased retention time
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What conditions can cause a decrease in stool retention time?
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irritable bowel
hyperthyroidism diabetic neuropathy Surgical resection |
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What conditions can increase stool retention time?
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Surgical blind loop
Bacterial overgrowth |
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If your pt is a baby 6-24 months old with secretory diarrhea, what do you suspect?
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Rotavirus
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What is responsible for the most cases of non-bacterial foodborne illness?
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Norovirus
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What strain of E. coli makes Shiga-toxin?
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O157:H7
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What species of salmonella can invade the mucosa and cause systemic illness?
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S. typhi
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What is the typical antecedent for C. diff infection?
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antibiotic use
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What is the key feature of C. diff infection?
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pseudomembraneous colitis
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Why would Zollinger-Ellison cause a malabsorptive condition?
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Gastrinoma causing massive acid production denatures pancreatic enzymes.
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How can a biliary obstruction cause malabsorption?
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No bile salts to solubilize fats
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What causes lactose intolerance?
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disaccharidase deficiency
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What is celiac sprue?
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gluten sensitivity enteropathy caused by a reaction to gliadin, occurs in proximal small bowel
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How does lymphatic obstruction cause malabsorption?
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fat that is absorbed travels out of the GIT via the lymph system.
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What is tropical sprue?
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inflammation of the small intestine due to mystery bug, but treated with antibiotics.
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What causes Whipple disease?
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Tropheryma whippelii
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What tissues are effected by whipples?
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any organ but mostly intestine, CNS and joints
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How is Whipple dx?
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PAS positive macrophages in lamina propria
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What does stool from a pt with malabsorption look like?
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greasy, bulky, yellow or gray in color.
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What test is used to determine celiac sprue?
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Anti-gliadin
More specific: Anti-endomysial Anti-tissue transglutaminase |
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How do you treat the villous atrophy caused by celiac sprue?
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remove gluten from diet
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Where is the highest incidence of Crohn's? At what age?
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US, Europe, Scandinavia (Whites)
Most often among females in their teens and twenties. |
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What is the clinical presentation of Crohn's?
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Episodes of diarrhea, cramping, pain, and fevers lasting days to weeks
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Describe the sequelae of Crohn's.
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1. fistula formation
2. abd abscess or peritonitis 3. stricture and obstruction 4. 6 fold increase in risk of colon cancer |
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What areas could be effected by Crohn's?
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Mouth to anus
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What are skip lesions and what disease are they associated with?
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CROHN'S
Lesions in the bowel with scattered areas of normal bowel intervening. |
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Which inflammatory bowel dz will have thickened intestinal walls with serositis and creeping fat?
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Crohn's
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What is the depth of effect tissue with Crohn's?
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transmural
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Noncaseating granulomas are associated with which inflammatory bowel dz?
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Crohn's
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Which inflammatory bowel dz will form fissures with tracts?
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Crohn's
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Which inflammatory bowel dz is characterized as showing cobblestoning?
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Crohn's
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What is the peak incidence of UC? With who?
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Whites 20-25 y/o
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What other conditions are typically associated with UC?
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autoimmune dz
migratory polyarthritis |
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Where is UC found?
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80% in the rectum and rectosigmoid
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Which inflammatory bowel dz will have pseudopolyps?
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UC
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Why is UC not associated with fat/vitamin malabsorption?
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Not associated with small intestine
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What is the presentation of UC?
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relapsing attacks of bloody diarrhea
cramps, tenesmus and colicky pain relieve by defecation. |
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What is a characteristic feature of UC in regards to colonic crypts?
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UC has crypt abscesses filled with pmns
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What part of the bowel is effected by UC?
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Colon
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What is backwash ileitis?
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penetration of the ileo-cecal valve and the distal small bowel with UC
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In which inflammatory bowel dz will you find crypt abscesses?
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UC
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Which inflammatory bowel dz will show flat mucosa?
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UC
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Which inflammatory bowel dz is at greater risk for carcinoma?
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UC
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What are some common causes of bowel obstruction?
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Herniation
Adhesions Intussusception Volvulus Tumors |
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What is a pedunculated polyp? Sessile
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pedunculated: polyp with a stalk
Sessile: no stalk |
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Polyps from epithelial proliferation are ________.
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True neoplasms: adenomas
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What are polyps due to abnormal maturation or inflammation called?
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hyperplastic polyps
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What are the majority of polyps? How big are they? Malignant?
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Hyperplastic (90%)
<5 mm and benign |
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What are juvenile polyps?
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benign hamartomas that typically occur in the rectum
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What is a Peutz-Jegher polyp?
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Part of PJ syndrome.
Haratomatous polyps that look like trees: neoplastic with proliferation of glands. |
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What is the progression of benign polyps to malignant ones?
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1. Hyperplastic
2. Juvenile 3. tubular adenomas 4. tubulovillous 5. villous (Worst) |
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Which adenomas of the colon have stalks?
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tubular and tubulovillous
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What is the risk of carcinoma with a colonic adenoma?
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4x greater with adenomas (true neoplasms)
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What is the malignancy rate of villous adenomas?
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40%
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What is the risk of cancer with familial polyposis syndrome?
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100%
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What type of cancers are colorectal cancers? Who gets them?
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adenocarcinomas
Old people |
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What is the main factor for the colorectal cancer?
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Dietary
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What percent of colorectal cancers are in the ascending colon?
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25%
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Where would you find a napkin-ring colon tumor?
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in the distal colon
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Where would you find a fungating, polyoid colon tumor?
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proximal colon
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What is iron deficiency in older males?
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colon cancer until proven otherwise
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Where do colon cancers met to?
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LN, lungs, liver, bones, and peritoneal cavity
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What is CEA used for?
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Following tumor therapy
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What is the most important factor for colon cancer prognosis?
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Extent of tumor at dx
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Where do small intestinal malignant tumors occur? what are they? What do they look like?
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Napkin-ring adenocarcinomas in the duodenum
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What factors measure the malignancy of carcinoid tumors?
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size, location, and penetration
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Carcinoid tumors in what locations rarely met?
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appendiceal and rectal
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What is the size threshold for carcinoid tumors in the ilium, stomach, and colon to have already met at dx?
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>2cm
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What is the most common site of GI carcinoids?
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Appendix
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What is carcinoid syndrome?
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flushing, diarrhea, cramps, N/V etc.. caused by carcinoid tumor that secretes massive amounts of 5-HT.
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What percentage of pts with carcinoid tumors develop carcinoid syndrome?
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1%
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What percent of pts with carcinoid syndrome have metastatic carcinoid?
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20%
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What is the degradation product of 5-HT?
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5-HIAA
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How do you dx carcinoid syndrome?
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5-HIAA in 24hr urine
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What is the most common extranodal site for lymphoma?
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GIT
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What type of lympnomas are primary GIT?
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B-cell
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Are GIT lymphomas better prognostically than nodal lymphomas?
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Yes
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What percent of acute appendicitises are associated with obstruction?
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up to 80%
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What percent of normal appendices are removed?
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25%
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What is an appendix mucocele?
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non-neoplastic obstruction of the lumen, associated with poop
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