Pathology of the small intestine I

Question 1

which cells of the GI tract are constantly proliferating?

Answer 1

basal cells

Question 2

what is the proposed pathogenesis for IBD?

Answer 2

failure of immune regulation, genetic susceptibility, environmental triggers

Question 3

what appears to be the prime culprit in UC and CD?

Answer 3

T cells

Question 4

CD is likely the result of what type of reaction?

Answer 4

delayed type hypersensitivity

Question 5

UC is likely the result of what process?

Answer 5

excessive stimulation of TH2 cells

Question 6

what is characteristic of the inflammation seen in crohn disease?

Answer 6

transmural

Question 7

what is considered a strong risk factor in crohn disease?

Answer 7

smoking

Question 8

which IBD disease has a stronger risk of advancement to carcinoma?

Answer 8

ulcerative colitis

Question 9

skip lesions, aphthoid ulcers, and cobblestone mucosa are indicative of what IBD condition?

Answer 9

crohn disease

Question 10

what is the cause of the aphthous ulcers in crohn disease?

Answer 10

mucosal inflammation
early neutrophilic infiltration of epithelial layer
crypt abscesses

Question 11

are granulomas present in ulcerative colitis? what about crohn disease?

Answer 11

UC - no

CD - yes

Question 12

what is the stool appearance in crohn disease?

Answer 12

bloody, mucoid diarrhea

Question 13

what is a defining feature of chronic ulcerative colitis?

Answer 13

pseudopolyps

Question 14

what are the complications of ulcerative colitis?

Answer 14

toxic megacolon, perforation

Question 15

what is the effect on the muscularis propria and serosa in ulcerative colitis?

Answer 15

no effect

Question 16

what are the mucosal changes that occur during ulcerative colitis?

Answer 16

crypt distortion

mucosal simplification and dysplasia

Question 17

what is the main complication of ulcerative colitis?

Answer 17

carcinoma

Question 18

what is the molecular pathology associated with ulcerative colitis?

Answer 18

DNA repair deficiency - microsatellite instability in mucosal cells

Question 19

where does ischemic colitis typically occur?

Answer 19

watershed areas of

splenic flexure (SMA and IMA) 
rectosigmoid (IMA and hypogastric artery)

Question 20

what are the causes of ischemic bowel disease?

Answer 20

embolism (arterial)
thrombosis (arterial and venous)
low flow
radiation, volvulus, stricture

Question 21

what is the cause of transmural infarction? what does it eventually lead to?

Answer 21

acute vascular obstruction

gangrene

Question 22

what is the cause of mural and mucosal infarction?

Answer 22

acute or chronic hypoperfusion

Question 23

definition: angiodysplasia

Answer 23

non-neoplastic vascular dilation and malformation of submucosal, mucosal blood vessels in cecum and ascending colon

Question 24

what is the morphology, pathogenesis, and course of diverticular disease?

Answer 24

morphology - sigmoid

pathogenesis - focal weakness in colonic wall and increased luminal pressure, low fiber diet

course - mostly asymptomatic

Question 25

diverticula occur in weakest areas of what layers?

Answer 25

submucosa and muscularis propria

Question 26

what are the main intestinal obstruction conditions?

Answer 26

hernias
adhesions
intussusception

Question 27

intussusception in infants is usually due to what causes?

Answer 27

lymphoid hyperplasia

rotavirus infection

Question 28

intussusception in adults is usually due to what causes?

Answer 28

intraluminal mass or tumor (point of traction)

Question 29

what are the consequences of malabsorption in the hematopoietic system?

Answer 29

anemia, bleeding (vitamin K)

Question 30

what are the consequences of malabsorption in the musculoskeletal system?

Answer 30

osteopenia, tetany

Question 31

what are the consequences of malabsorption in the endocrine system?

Answer 31

amenorrhea, impotence, infertility, hyperthyroidism

Question 32

what are the consequences of malabsorption in the skin?

Answer 32

purpura, petechiae, edema, dermatitis, hyperkeratosis

Question 33

what are the consequences of malabsorption in the nervous system? which compounds are responsible?

Answer 33

peripheral neuropathies

B12, vitamin A

Question 34

whipple disease affects which systems?

Answer 34

intestine, CNS, joints

Question 35

what is the hallmark feature of whipple disease?

Answer 35

macrophages stuffed with PAS-positive granules in small bowel, skin, CNS, joints, brain, kidney, liver, lymph nodes, spleen, liver

Question 36

what is the effect of tropical sprue on the small bowel?

Answer 36

folate and / or B12 deficiency, megaloblastic anemia in intestinal cells