Pathology of the small intestine I Flashcards
which cells of the GI tract are constantly proliferating?
basal cells
what is the proposed pathogenesis for IBD?
failure of immune regulation, genetic susceptibility, environmental triggers
what appears to be the prime culprit in UC and CD?
T cells
CD is likely the result of what type of reaction?
delayed type hypersensitivity
UC is likely the result of what process?
excessive stimulation of TH2 cells
what is characteristic of the inflammation seen in crohn disease?
transmural
what is considered a strong risk factor in crohn disease?
smoking
which IBD disease has a stronger risk of advancement to carcinoma?
ulcerative colitis
skip lesions, aphthoid ulcers, and cobblestone mucosa are indicative of what IBD condition?
crohn disease
what is the cause of the aphthous ulcers in crohn disease?
mucosal inflammation
early neutrophilic infiltration of epithelial layer
crypt abscesses
are granulomas present in ulcerative colitis? what about crohn disease?
UC - no
CD - yes
what is the stool appearance in crohn disease?
bloody, mucoid diarrhea
what is a defining feature of chronic ulcerative colitis?
pseudopolyps
what are the complications of ulcerative colitis?
toxic megacolon, perforation
what is the effect on the muscularis propria and serosa in ulcerative colitis?
no effect
what are the mucosal changes that occur during ulcerative colitis?
crypt distortion
mucosal simplification and dysplasia
what is the main complication of ulcerative colitis?
carcinoma
what is the molecular pathology associated with ulcerative colitis?
DNA repair deficiency - microsatellite instability in mucosal cells
where does ischemic colitis typically occur?
watershed areas of
splenic flexure (SMA and IMA) rectosigmoid (IMA and hypogastric artery)
what are the causes of ischemic bowel disease?
embolism (arterial)
thrombosis (arterial and venous)
low flow
radiation, volvulus, stricture
what is the cause of transmural infarction? what does it eventually lead to?
acute vascular obstruction
gangrene
what is the cause of mural and mucosal infarction?
acute or chronic hypoperfusion
definition: angiodysplasia
non-neoplastic vascular dilation and malformation of submucosal, mucosal blood vessels in cecum and ascending colon
what is the morphology, pathogenesis, and course of diverticular disease?
morphology - sigmoid
pathogenesis - focal weakness in colonic wall and increased luminal pressure, low fiber diet
course - mostly asymptomatic
diverticula occur in weakest areas of what layers?
submucosa and muscularis propria
what are the main intestinal obstruction conditions?
hernias
adhesions
intussusception
intussusception in infants is usually due to what causes?
lymphoid hyperplasia
rotavirus infection
intussusception in adults is usually due to what causes?
intraluminal mass or tumor (point of traction)
what are the consequences of malabsorption in the hematopoietic system?
anemia, bleeding (vitamin K)
what are the consequences of malabsorption in the musculoskeletal system?
osteopenia, tetany
what are the consequences of malabsorption in the endocrine system?
amenorrhea, impotence, infertility, hyperthyroidism
what are the consequences of malabsorption in the skin?
purpura, petechiae, edema, dermatitis, hyperkeratosis
what are the consequences of malabsorption in the nervous system? which compounds are responsible?
peripheral neuropathies
B12, vitamin A
whipple disease affects which systems?
intestine, CNS, joints
what is the hallmark feature of whipple disease?
macrophages stuffed with PAS-positive granules in small bowel, skin, CNS, joints, brain, kidney, liver, lymph nodes, spleen, liver
what is the effect of tropical sprue on the small bowel?
folate and / or B12 deficiency, megaloblastic anemia in intestinal cells
