Pathology of Small Bowel

Question 1

types of ischaemia of the small bowel

Answer 1

mesenteric arterial occlusion
non occlusive perfusion insufficiency

usually acute but can be chronic

Question 2

aetiology of ishcaemia of the small bowel - mesenteric arterial occlusion

Answer 2

mesenteric artery atherosclerosis

thromboembolism from heart (AF)

Question 3

aetiology of ishcaemia of the small bowel - non occlusive perfusion insufficiency

Answer 3

shock
strangulation obstructing venous return (hernia, adhesion)
drugs (cocaine)
hyper viscosity

Question 4

describe mucosa of the small bowel

Answer 4

most metabolically active part of bowel wall - most sensitive to effects of hypoxia

Question 5

pathogenesis of ischaemia if small bowel - mesenteric arterial occlusion

Answer 5

longer the hypoxia the greater the depth of damage to the bowel wall and greater the likelihood of complications

Question 6

pathogenies of ischaemia of small bowel - non occlusive ischaemia

Answer 6

tissue damage occurs after reperfusion

Question 7

types of small bowel infarction

Answer 7

mucosal
mural
transmural

Question 8

complications of ischaemia the small bowel

Answer 8

resolution
fibrosis, stricture, chronic ishcaemia, mesenteric angina and obstruction
gangrene, perforation, peritonitis, sepsis and death

Question 9

what is Meckel’s Diverticulum

Answer 9

result of incomplete regression of Vitelli-intestinal duct

Question 10

pathogenesis of Meckel’s Diverticulum

Answer 10

tubular structure, above IC valve

may contain heterotypic gastric mucosa

Question 11

signs of Meckel’s Diverticulum

Answer 11

asymptomatic;
bleeding
perforation
diverticulitis mimicking appendicitis

Question 12

tumours of the small bowel

Answer 12

primary - rare

secondary - common (ovary, colon and stomach)

Question 13

primary tumours of the small bowel

Answer 13

lymphomas
carcinoid tumours
carcinomas

Question 14

lymphomas of small bowel

Answer 14

rare all non Hodkins in type

Question 15

pathology of lymphomas of small bowel

Answer 15

maltomas (B cell) derived

enteropathy associated T-cell lymphomas (associated with Coeliac disease)

Question 16

treatment for lymphomas of small bowel

Answer 16

surgery and chemotherapy

Question 17

carcinoid tumours of small bowel

Answer 17

most commonly found in appendix
small, yellow, slow growing tumours
locally invasive

Question 18

pathology of carcinoid tumours of small bowel

Answer 18

can cause intussusception, obstruction

produces hormone like substances if metastases to liver producing flushing and diarrhoea

Question 19

describe carcinoma of small bowel

Answer 19

associated with Crohn’s disease and Coeliac disease

presents late

Question 20

pathology of carcinoma of small bowel

Answer 20

identical to colorectal carcinoma in appearance

metastases to lymph nodes and liver occurs

Question 21

describe appendicitis

Answer 21

common cause of acute abdomen

commoner in children but occurs in adults

Question 22

symptoms of appendicitis

Answer 22

vomiting
abdominal pain
right iliac fossa tenderness
increased white cell count

Question 23

aetiology of acute appendicitis

Answer 23

unknown 
faecoliths (dehydration)
lymphoid hyperplasia 
parasites
tumours (rare)

Question 24

pathology of appendicitis

Answer 24

acute inflammation (neutrophils) involving muscles coat (mural)
mucosal ulceration
serosal congestion, exudate
pus in lumen

Question 25

complications of appenditics

Answer 25

``` peritonitis rupture abscess fistula sepsis and liver abscess ```

Question 26

what is coeliac disease

Answer 26

abnormal reaction to constituent of wheat flour, gluten

Question 27

pathology of coeliac disease

Answer 27

effects small intestine; damaging enterocytes - reducing absorptive capacity, loss of villous structure, loss of surface area, flat duodenal mucosa

Question 28

aetiology of coeliac disease

Answer 28

gliadin (component of gluten); tissue injury as bystander effect IEL and CD8 T cell mediated

Question 29

metabolic effects of coeliac disease

Answer 29

malabsorption | reduced intestine hormone production

Question 30

what substances does malabsorption affect

Answer 30

``` fats sugars amino acids water electrolytes ```

Question 31

what does malabsorption of fats lead to

Answer 31

steatorrhea

Question 32

what does reduced intestinal hormone production lead to

Answer 32

reduced pancreatic secretion and bile flow (CCK) - leading to gallstones

Question 33

complications of malabsorption

Answer 33

``` weight loss anaemia abdominal bleeding failure to thrive vitamin deficiencies T-cell lymphomas of GI tract increased risk of small bowel carcinoma gallstones ulcerative-jejenoilleitis ```