Pathology- the small bowl

Question 1

What is the small bowl

Answer 1

the small intestine

Question 2

what is the innermost cell of the small bowl

Answer 2

enterocytes lined with villi

Question 3

what is the main function of the villi

Answer 3

absroption

Question 4

what is the blood supply to the small bowl

Answer 4

entire supply from superior mesenteric

Question 5

what can cause ischaemia of the small bowl

Answer 5

mesenteric artery occlusion

non occlusive perfusion insufficiency

Question 6

what can cause mesenteric artery occlusion

Answer 6

mesenteric artery atherosclerosis

thromboembolism from heart (e.g. A fib)

Question 7

what can cause a non occlusive perfusion insufficiency

Answer 7

shock (when haemorrhaging as brain, heart and lungs a priority)

strangulation obstructing venous return (e.g. hernia or adhesion)

drugs (e.g. cocaine, causes spasm of intestinal wall)

hyperviscosity

Question 8

what pain is associated with ischaemia of the small bowl

Answer 8

acute pain as usually acute, can by chronic

Question 9

why is the mucosa the area most affected by an infarction (the effects of hypoxia)

Answer 9

as it is the most metabolically active area

Question 10

what increases with the period of hypoxia

Answer 10

the greater the dept of the damage to the bowl wall and likelyhood of complications

Question 11

in non occlusive ischaemia when does much of the tissue damage occur

Answer 11

after reperfusion

Question 12

what is a possible outcome from the following

• mucosa infarct
• mural infarct
• transmural infarct

Answer 12

different types of infarct occur as the length og time of ischaemia increases. the outcomes also get worse

• regeneration
• stricture (abnormal narrowing caused by firbous scarring during healing)
• gangrene (when infarct goes through the bowl)

Question 13

what are the complications of ischaemia of the small bowl

Answer 13

mucosa
resolution

mural
fibrosis, stricture, chronic ischaemia, mesenteric angina, obstruction,

transmural
gangrene, perforation, peritonitis, sepsis, death

Question 14

what is meckel’s diverticulum

Answer 14

is a result of imcomplete regression of vitello-intestinal duct (embryological feature)

Question 15

describe meckels diverticulum

Answer 15

Tubular structure, 2 inches long, 2 foot above IC (illeocecal) valve in 2% of people

May contain heterotopic gastric mucosa

Question 16

what can a mekels diverticulum cause

Answer 16

bleeding, perforation or diverticulitis which mimicks appendicitis, peptic ulcers

Commonly assymptomatic, incidental finding

Question 17

what tumours are most common in the small bowel

Answer 17

primary tumours rare 
secondary tumours (metastases from ovary, colon and stomach) more common 
primary tumours include 
-lymphomas
-carcinoid tumours
-carcinomas
(in order of commonness)

Question 18

what type are the lymphomas of the bowel

Answer 18

non hodkins in type

Question 19

how are lymphomas of the bowel treated

Answer 19

surgery and chemotherapy

Question 20

where is the most common site for a carcinoid tumour in the small bowl

Answer 20

the appendix

Question 21

describe carcinoid tumours of the bowel

Answer 21

small, yellow, small growing, locally invasive, produces hormone like substances, if metastases to liver causes a carcinoid tumour producing flushing, diarrhoea and head aches

Question 22

what cancer is associated with coeliac disease

Answer 22

lymphomas

Question 23

describe carcinomas of the small bowel

Answer 23

rare, presents late, metastases to lymph nodes and liver occur

Question 24

what bowl cancer is associated to crohns and coeliac disease

Answer 24

carcinoma (as they are predisposed to rarer cancers)

Question 25

what are the symptoms of an appendicitis

Answer 25

vomiting, abdominal pain, right illiac fossa, increased white cell count

Question 26

what can cause an cute appendicitis

Answer 26

unknown (most common), faecoliths (dehydration), lymphoid hyperplasia, parasites, tumours (rare)

Question 27

describe the pathology of an acute appendicitis

Answer 27

Acute inflammation (neutrophils)- must involve a muscle coat Mucosal ulceration Serosal congestion, exudate Pus in lumen

Question 28

what happens to the wall of the appendix during an acute appendicitis

Answer 28

is thickened, neutrophils invade it, inflammation

Question 29

what are the complications of an appendicitis

Answer 29

peritonitis, rupture, abscess, fistula, sepsis and liver abscess

Question 30

how can an acute appendicitis cause a liver abscess

Answer 30

can spread to liver via portal system causing abscess of liver

Question 31

what is coeliac disease caused by

Answer 31

an abnormal reaction to a constituent of wheat flour, gluten, which damages enterocytes and reduces absorptive capacity- damages villi

Question 32

when can coeliac disease present

Answer 32

any time

Question 33

what is coeliac disease strongly associated with

Answer 33

HLA-B8, dermatitis herpeformis, childhood diabetes

Question 34

what is the suspected auto antigen (toxic agent) in coeliac disease

Answer 34

gliadin (component of gluten) -tissue injury may be a bystander effect of abnormal immune reaction to Gliadin

Question 35

what is T cells role in coeliac disease

Answer 35

Mediated by T-cell lymphocytes which exist within the small intestinal epithelium ‘intraepithelial lymphocytes’ (IELS)

Question 36

what is the normal lifespan of an enterocyte

Answer 36

72 hours

Question 37

how is coeliac disease seen in the gut

Answer 37

increasing loss of enterocytes due to IEL mediated damage This leads to loss of villous structure, loss of surface area, a reduction in absorbtion and a flat duodenal mucosa (e.g. flat mucosal biopsy with total villous atropy)

Question 38

what is the morphology of coeliac disease

Answer 38

increased inflammation in lamina propria, increased intraepithelial lmphocytes

Question 39

what part of the bowl is usually worse in coeliac disease

Answer 39

proximal

Question 40

what antibodies will be found in someone with coeliac disease

Answer 40

anti-TTG, anti-endomesial, anti glandin

Question 41

what are the metabolic effects of coeliac disease

Answer 41

Malabsorbtion of sugars, fats, amino acids, water and electrolytes Malabsorbtion of fats leads to steatorrhea (excessive fat in poo) Reduced intestinal hormone production leads to reduced pancreatic secretion and bile flow (CCK) leading to gallstones

Question 42

what are the clinical effects of malabsorption

Answer 42

weight loss, anaemia, abdominal bloating, failure to thrive, vitamin deficiencies

Question 43

what are 4 rare complications of coeliac disease

Answer 43

T-cell lymphomas of GI tract Increased risk of small bowel carcinoma Gall stones Ulcerative-jejenoilleitis