Alimentary tract pathology

Question 1

What are the notes of mention for the hiistology of the small bowel?

Answer 1

The mucosa has innumerable villi
There are goblet cells, columnar absorbitive cells and endocrine cells
Also crypts have 4 cell types - stem, goblet, paneth, endocrine

Question 2

What cell types are found in the crypts within the large bowel?

Answer 2

goblet, endocrine and stem

Question 3

What are the chronic and acute causes for dysfunction of the GI tract immune system?

Answer 3

chronic disease and acute life threatening conditions including ecoli and salmonella

Question 4

How is peristalsis mediated?

Answer 4

intinsic - myenteric plexus and extrinsic by the autonomic nervous system

Question 5

What is idiopathic inflammatory bowel disease?

Answer 5

Chronic inflammatory conditions resulting from inappropriate and persistent activation of the mucosal immune system driven by the presence of normal intraluminal flora

Question 6

Where can crohns disease effect in the GI tract?

Answer 6

any part from mouth to anus

Question 7

Where can ulcerative coltits effect in the GI tract?

Answer 7

the large bowel

Question 8

What are the genes linked in genetics to crohn’s disease and ulcerative colitis?

Answer 8

NOD2

HLA

Question 9

What is the antibody pANCA role in inflammatory bowel disease?

Answer 9

75%+ in ulcerative colitis but only 11% in crohn’s disease

Question 10

What is the epidemiology of ulcerative colitis?

Answer 10

Male=female, peaks at 20-30 and 70-80 years old

Question 11

What is proctitis?

Answer 11

ulcerative colitis limited to the rectum

Question 12

What is pancolitis?

Answer 12

ulcerative colitis spanning the entire colon

Question 13

What is backwash ileitis?

Answer 13

ulcerative colitis with inflammation seen in the distal ileum

Question 14

How does ulcerative colitis spread?

Answer 14

rectum –> proximal

Question 15

Does crohns or ulcerative colitis have granulomas?

Answer 15

crohns - non caseating

Question 16

Does crohns or ulcerative colitis have skip lesions with a patchy distribution?

Answer 16

crohn’s

Question 17

Explain the epidemiology of crohn’s disease

Answer 17

female predominant, effects anywhere from mouth to anus and also have peaks at ages 20-30 and 60-70 with the majority being found in the small intestine

Question 18

What are the long term features of crohn’s disease?

Answer 18

increased cancer risk
malabsorption
strictures, fistulas, abscesses and perforation

Question 19

What can acute occlusion of one of the 3 main vessels of the gut lead to?

Answer 19

infarction - can lose part of the bowel

Question 20

What are predisposing conditions for ischaemic enteritis?

Answer 20

arterial thrombosis eg oral contraceptives, atherosclerosis

arterial embolism and non occlusive ischaemia eg shock and dehydration

Question 21

Where is particular;y vulnerable in acute ischaemia?

Answer 21

splenic flexure

Question 22

Explain the difference between arterial and venous appearance in acute ischaemia?

Answer 22

arterial is sharp whereas venous is a gradual fade

Question 23

What can ischaemia lead to?

Answer 23

necrosis and gangrene accompanied by oedema and indistinct nuclei

Question 24

What can chronic ischaemia lead to?

Answer 24

ulceration, fibrosis and stricture

Question 25

What parts of the gut tube histologically are effected in chronic ischaemia by inflammation?

Answer 25

mucosa and submucosa

Question 26

What is radiation colitis?

Answer 26

abdominal irradiation impairing the normal proliferative activity of the small and large bowel epithelium, usually with rectum-pelvic radiotherapy targeting blood vessels and crypts

Question 27

symptoms of radiation colitis?

Answer 27

anorexia, abdominal cramps, diarrhoea and malabsorption

Question 28

What are the 2 knock-on effects of acute inflammation of the appendix?

Answer 28

obstruction | increased intraluminal pressure - ischaemia

Question 29

What is seen both macroscopically and microscopically in appendicitis?

Answer 29

exudate, perforation and abscess | inflammation, necrosis and gangrene

Question 30

What are the 2 grades of large bowel dysplasia and differentiate them

Answer 30

low - increased nuclear size and number with reduced mucin | high - carcinoma in situ, crowded and irregular

Question 31

What are the 3 types of adenoma in large bowel dysplasia?

Answer 31

tubular villous tubulovillous

Question 32

what are the majority of carcinoma in the large bowel cell type?

Answer 32

adenocarcinoma usually of pre-existing polyps

Question 33

What are risk factors for adenocarcinoma of the large bowel?

Answer 33

lifestyle family history genetics eg FAP, HNPCC IBD

Question 34

Symptoms of right and left sided bowel neoplasia?

Answer 34

``` right = anaemia, vague pain, weakness left = blood from rectum, altered bowel habit ```

Question 35

What are the 2 scales used to stage large bowel cancer for prognosis?

Answer 35

TNM | Dukes - A,B,C1,C2