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Flashcards in pathology of malabsorption Deck (16):
1

what are the signs of malabsorption?

weight loss
pale stools or steatorrhoea
anaemia

2

what should be established first before thinking about a pathological reason for malabsorption?

check that the pt's diet is balanced

3

what part of the intestine is where cells divide to form new cells?

the crypts

4

is it normal for their to be lymphocytes in the villi of the intestine?

yes, small numbers are fine as these fight off infection in the food

5

what are the causes of malabsorption?

insufficient intake
defective intraluminal digestion
insufficient absorptive area
lack of digestive enzymes
defective epithelial transport
lymphatic obstruction

6

give reasons for defective intraluminal digestion

pancreatic insufficiency: pancreatitis and CF both mean that pancreatic enzymes cannot be produced
defective bile secretion - due to biliary obstruction and ileal resection; means less fat emulsion and decreased bile salt uptake respectively
bacterial overgrowth - bacteria use up the nutrients in the food, so they are not absorbed

7

what conditions cause insufficient absorptive area?

gluten sensitive enteropathy ie Coeliac
Crohn's disease
extensive surface parasitisation

8

How does gluten sensitive enteropathy look on histology?

short villi and larger crypts ie crypt hyperplasia
increased number of intraepithelial lymphocytes

9

what is coeliac disease?

allergic hypersensitivity reaction to gluten from wheat

10

explain the pathophysiology behind Coeliac disease

gliadin protein is absorbed from gluten
the gliadin protein binds to APCs
APCs present gliadin to toxic T cells
Toxic T cells cause epithelial cell injury by release of chemicals
transglutaminase Abs are produced which destroy the villi

11

which part of the bowel does Crohn's disease primarily affect?

small intestine

12

Give an example of a parasite that causes extensive surface parasitisation in the intestine?

Giardia lamblia

13

What happens in extensive surface parasitisation?

parasites prevent the absorption of food

14

What are the reasons that sb might have a small intestine resection or bypass?

morbid obesity
Crohn's disease
infarcted small bowel

15

What are some lack of enzyme diseases that can cause malabsoption?

disaccharidase deficiency (lactose intolerance)
bacterial overgrowth damages the brush border, so affects the release of enzymes

16

what two conditions can cause lymphatic obstruction and hence malabsorption?

lymphoma
TB