10.5 - Small bowel

Question 1

double bubble sign is seen in ______________

Answer 1

duodenal atresia

Question 2

does duodenal atresia have bilious or nonbilious vomiting?

Answer 2

bilious

Question 3

is meckel diverticulum a true or false diverticulum?

Answer 3

true

Question 4

what is the cause of a meckel diverticulum?

Answer 4

failure of vitelline duct to involute

Question 5

what are the most common sites of volvulus?

Answer 5

• sigmoid

- cecum

Question 6

in intussusception, which part telescopes?

Answer 6

telescoping of proximal segment forward into distal segment

Question 7

what is the most common cause of intussusception in children? adults?

Answer 7

• children: lymphoid hyperplasia

- adults: tumor

Question 8

transmural bowel infarction is due to _________________

Answer 8

thrombosis / embolism of SMA or mesenteric vein

Question 9

mucosal bowel infarction is due to _________________

Answer 9

marked hypotension

Question 10

thrombosis / embolism of SMA or mesenteric vein leads to what type of bowel infarction?

Answer 10

transmural

Question 11

marked hypotension leads to what type of bowel infarction?

Answer 11

mucosal

Question 12

where is the lactase enzyme located?

Answer 12

brush border of enterocytes

Question 13

lactase breaks down ____________ into _________ and ____________

Answer 13

• lactose

- glucose and galactose

Question 14

celiac disease is associated with what HLA haplotypes?

Answer 14

HLA-DQ2 and DQ8

Question 15

once absorbed, gliadin is deaminated by ____________

Answer 15

tissue transglutaminase (tTG)

Question 16

what immune cell mediates tissue damage in celiac disease?

Answer 16

helper T cells

Question 17

deamidated gliadin is presented by APCs via MHC ____

Answer 17

II

Question 18

dermatitis herpetiformis is seen in what condition? what is the pathophysiology?

Answer 18

• celiac

- deposition of IgA

Question 19

in celiac disease there are antibodies against ________ (3 antigens)

Answer 19

• tTG
• gliadin
• endomysium

Question 20

what is the duodenal biopsy histology seen in celiac disease?

Answer 20

• flattening of villi
• hyperplasia of crypts
• increased intraepithelial lymphocytes

Question 21

in celiac disease, which segment of the GI tract is most heavily involved?

Answer 21

duodenum

Question 22

what are late complications of celiac disease despite good dietary control?

Answer 22

• small bowel carcinoma

- T cell lymphoma

Question 23

duoenal biopsy show:

• flattening of villi
• hyperplasia of crypts
• increased intraepithelial lymphocytes

diagnosis?

Answer 23

celiac disease

Question 24

where is damage most prominent in tropical sprue?

Answer 24

jejunum and ileum

Question 25

whipple disease is a systemic tissue disease characterized by _________ loaded with tropheryma whippelii

Answer 25

macrophages

Question 26

what is the classic site of involvement in whipple disease?

Answer 26

small bowel lamina propria

Question 27

what is the pathophysiology of whipple disease?

Answer 27

- macrophages compress lacteals - chylomicrons cannot be transferred from enterocytes to lymphatics - fat malabsorption and steatorrhea

Question 28

what is the cause of steatorrhea in whipple disease?

Answer 28

- macrophages compress lacteals | - chylomicrons cannot be transferred from enterocytes to lymphatics

Question 29

PAS positive organisms are observed macrophage lysosomes of the small bowel lamina propria - diagnosis?

Answer 29

whipple disease

Question 30

what is the inheritance of abetalipoproteinemia?

Answer 30

AR

Question 31

abetalipoproteinemia is an AR deficiency of _________ and __________

Answer 31

B48 and B100

Question 32

what are the features of abetalipoproteinemia?

Answer 32

- malabsorption | - absent plasma VLDL and LDL

Question 33

in abetalipoproteinemia which lipoproteins are absent? why?

Answer 33

- VLDL and LDL | - these require B-100

Question 34

what is the cause of malabsorption in abetalipoproteinemia? why?

Answer 34

- defective chylomicron formation | - requires B48

Question 35

carcinoid tumor is a malignant proliferation of what type of cells?

Answer 35

neuroendocrine

Question 36

carcinoid tumors have tumor cells containing neurosecretory granules that stain positive for _____________

Answer 36

chromogranin

Question 37

how does carcinoid sydrome arise?

Answer 37

metastasis of carcinoid tumor from GI tract (small bowel) to the liver, bypassing metabolism

Question 38

what are the findings of carcinoid syndrome?

Answer 38

- bronchospasm - diarrhea - flushing

Question 39

what are the findings in carcinoid HEART disease?

Answer 39

- right sided valvular fibrosis (increased collagen) - tricuspid regurg - pulmonary stenosis

Question 40

why aren't left sided lesions seen in carcinoid heart disease?

Answer 40

due to presence of MAO (metabolizes serotonin)