small intestine

Question 1

complications of refractory celiac dz despite gluten free diet

Answer 1

t cell lymphoma

SI adenocarcinoma

Question 2

biological causes of malabsorption in viral, bacterial and parasitic gastroenteritis

Answer 2

terminal digestion and transepithelial transport

Question 3

describe the pathogenesis of adhesions

Answer 3

• MC type of intestinal obstruction in the US
• peritoneal inflammation (congenital or acquired from surgery/trauma)–> adhesions/fibrous bridges–> entrapped viscera (internal herniation) –> obstruction , strangulation

Question 4

complications of external herniation (visceral protrusion of GI tract )

Answer 4

incarceration, strangulation, and infarction

-impaired venous return–>stasis/edema–> enlarged hernia, permanent entrapment (incarceration) –> arterial/venous compromise (strangulation) –> infarction

Question 5

what pathology is associated with lipid accumulation seen with red-o oil stain

Answer 5

abetalipoprotienima

Question 6

biological causes of malabsorption in acetalipoproteinemia

Answer 6

transepithelial transport

Question 7

biological causes of malabsorption in chronic pancreatitis, and cystic fibrosis

Answer 7

intraluminal digestion

Question 8

AR DO presents in infants with inability to secrete triglyceride rice lipoproteins (APOB 48 and APOB 100) due to MTP mutation

Answer 8

abetalipoprotienima

• APOB48 makes chylomicrons
• APOB100 makes LDL VLDL

Question 9

most common presentation of malabsorption

Answer 9

chronic diarrhea

others: wt loss, distention, borborygmi (rumbling), muscle wasting, steatorrhea

Question 10

congenital lactase deficiency vs acquired

Answer 10

congenital: (rare) AR DO with explosive osmotic watery diarrhea, frothy stools, ab distention all on consumption of milk
acquired: decrease regulation of lactase gene common in native americans, african americans, chinese/ sx: ab fullness, osmotic diarrhea, gas on consumption of dairy
* may be TEMPORARY kind following infections with similar symptoms

Question 11

4 types of diarrhea

Answer 11

1. secretory - isotonic stool; persistent with fast
2. osmotic- osm gap; decrease with fast
3. malabsorptive- steatorrhea; decrease with fast
4. exudative - purulent, bloody, persistent with fast

Question 12

telescoping of proximal segment of bowel forward to distal segment associated with leading edge

Answer 12

intusseception

-can lead to obstruction and infarction

Question 13

common causes and clinical manifestation of intestinal obstruction

Answer 13

common causes: hernias, adhesions, intussusception, volvulus
-clin man: ab pain, distension, vommitting, constipation

Question 14

grows as a submucosal polyp like nodule and secretes serotonin in urine

Answer 14

midgut carcinoid tumor (jejunum/ileum)

• healthy liver = 5HIAA in urine and no carcinoid syndrome, heart disease
• liver metastais = bypass liver and serotonin is systemic causing right heart disease (R valve collagen/fibrosis –> PS or TR) and carcinoid syndrome (flushing, diarrhea, bronchospasm)

Question 15

IPEX -X linked DO; causing FoxP3 mutation of CD4 T-reg cells resulting in antibodies to enterocyte goblet cells, parietal cells, or islet cells
*sx: severe persistent diarrhea and AI dz in young children

Answer 15

autoimmune enteropathy

Question 16

biological causes of malabsorption in lactose def

Answer 16

terminal digestion

Question 17

gross and histo of carcinoid tumor

Answer 17

gross: yellow/tan
histo: “salt n pepper” cytology
- dense core with neurosecreotry granules on EM (chromogranin A positive if midgut)

Question 18

pathogenesis of celiac disease

Answer 18

deaminated gliadin by tissue transglutaminase (tTG) is presented to CD4+ T helper cells via MHC II; the T cells imitate damage

Question 19

what is the most common cause of intussecpition in adults

Answer 19

tumor or mass

Question 20

4 main biological causes of malabsorption

Answer 20

1. defect intraluminal digestion
2. defect terminal digestion
3. defect transepithelial transport
4. defect lymphatic transport of lipids

Question 21

t/f

because lactase deficiency defect is biochemical a biopsy of the brush border will be normal

Answer 21

true

-where lactose is normally located

Question 22

3 variables of severity of SI infarction

Answer 22

1. duration
2. artery associated
3. severity of compromise

Question 23

lab findings of celiac dz

Answer 23

IgA ab vs endymysion, tTG, and gliadin

*if IgA def then it is IgG type

Question 24

what is the most common cause of intestinal obstruction in children under the age of 2 yo

Answer 24

intusseception

-due to lymphoid (peters patch) hyperplasia due to rotavirus infection at the terminal ileum –> cecum

Question 25

biosy findings of celiac dz

Answer 25

flat vili, crypt hyperplasia, CD8 intraepithelial lymphocytes *immune mediated damage of SI villi (most commonly the DUODENUM)

Question 26

cause of a transmural vs mucosal SI infarct and associated sx

Answer 26

transmural- hypercoaguble state and thromboembolism of the SMA or thrombosis of mesenteric vein mucosal- marked hypotension (possibly shock) sx: ab pain, BLOODY diarrhea, decreased bowel sounds (paralytic ileus- might need surgery)

Question 27

average size of midgut carcinoid tumor and what are it secretions

Answer 27

<3.5cm (but aggressive) | -secrete: serotonin, Substance P, and PYY

Question 28

biological causes of malabsorption in celiac dz

Answer 28

transepithelial transport and terminal digestion

Question 29

carcinoid tumor causes _____ if liver metastasis

Answer 29

chronic diarrhea

Question 30

twisting of the bowel about its mesentery

Answer 30

volvulus | -can lead to obstruction and infarction

Question 31

most common site of volvulus

Answer 31

elderly - sigmoid colon | young adult - cecum

Question 32

extra GI sx of celiac dz

Answer 32

dermatitis herpetiformis, iron def anemia, apthous ulcers, short state,

Question 33

MCC of malabsorption in the US

Answer 33

1. pancreatic insufficiency 2. celiac DZ 3. Crohns (IBD)

Question 34

neurosecretory granules in midgut carcinoid tumor are ______ positive

Answer 34

Chromogranin A + tumor cells

Question 35

biological causes of malabsorption in whipple disease

Answer 35

lymphatic transport

Question 36

sx of abetalipoprotienima

Answer 36

FTT, diarrhea, malabsorption, steatorrhea, absent plasma lipoproteins (VLDL and LDL) -fat vitamin def = membrane defects seen as acanthocythic RED cells (BURR CELLs) seen on peripheral blood smear

Question 37

biological causes of malabsorption in Crohns

Answer 37

intraluminal digestion, terminal digestion, transpithelial transport