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Flashcards in Pathology of Small bowel Deck (28)
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1
Q

What supplies the small bowel?

A

Superior mesenteric artery

2
Q

What are the 2 types of ischeamia of the small bowel?

A

Mesenteric arterial occlusion

Non-occlusive perfusion insufficiency

3
Q

What causes mesenteric arterial occlusion?

A

Mesenteric artery atherosclerosis

Thomboembolism from the heart (A.fib, subactute endocarditis, mural thrombus)

4
Q

What can cause non occlusve perfusino insufficiency?

A

Shock
Strangulation obstructing venous return (hernia, adhesion)
Drugs e.g. cocaine (vasospasm)
Hyperviscosity

5
Q

What part of the bowel is most sensitive to the effects of hypoxia?

A

The mucosa is the most metabolically active part of the bowel wall and therefore the most sensitive to the effects of hypoxia

6
Q

What occurs the longer the hypooxia occurs?

A

The greater the depth of the damage to the bowel wall and the greater the likelyhood of complications

7
Q

When does the tissue damage occur in non occlusive ischaemia?

A

After reperfusion

8
Q

What are the complications of ischaemia of the small bowel?

A

Resolution
Fibrosis, stricture, chronic ischaemia, mesenteric angina, obstruction
Gangrene, perforation , peritonitis, sepsis and death

9
Q

What is meckel’s diverticulum?

A

A result of incomplete regression of the vitello-intestinal duct. Tubular structure, 2 inches long, 2 foot above the ileocaecal valve
May contain heterotropic gastric mucosa

10
Q

What are the complications of meckel’s diverticulum?

A

Bleeding, perforation or diverticulitis that mimicks appendicitis

11
Q

What are the primary tumours that can occur in the small bowel (rare)?

A

Lymphomas
Carcionid tumour
Carcinomas

12
Q

What is non-hodgkin’s lymphoma?

A

Non-Hodgkin lymphomas (NHLs) are tumors originating from lymphoid tissues, mainly of lymph nodes.

13
Q

What is a carcinoid tumour?

A

Carcinoid tumors are of neuroendocrine origin and derived from primitive stem cells in the gut wall

14
Q

What is carcinoid sydrome?

A

Paraneoplastic syndrome that causes flushing and diarrhea, and less frequently, heart failure, emesis and bronchoconstriction. It is caused by endogenous secretion of mainly serotonin and kallikrein.

15
Q

What is a carcinoma?

A

Cancer of the epithelium - can be basal, squamous cell, adenocarcinoma

16
Q

Where are carcinoid tumours of the small bowel usually found?

A

Commonest site is the appendix, small, yellow, slow growing tumours

17
Q

What are carcinoma’s of the small bowel associated with?

A

Crohn’s disease and coeliac disease. Crohn’s predisposes to adenocarcinomas

18
Q

Where will carcinoma’s of the small bowel metastasise to?

A

Lymph nodes and liver

19
Q

What are the symptoms of appendicitis?

A

Vomiting, abdominal painn, right iliac fossa tenderness and increased white cell count

20
Q

What is the aetiology of acute appendicitis?

A
Unkown 
Faecoliths
Lymphoid hyperplasia 
Parasites
Tumours (rare)
21
Q

What is the pathology of acute appendicitis?

A
Acute inflammation (neutrophils) 
Mucosal ulceration 
Serosal conngestion , exudate 
Pus in lumen 
Acute inflammation MUST involve the muslce coat
22
Q

What are the complications of acute appendicitis?

A
Peritonitis
Rupture
Abscess
Fistula
Sepsis and liver abscess
23
Q

What is coeliac disease?

A

Abnormal reaction to a connstituent of wheat flour, gluten, which damages enterocytes annd reduces absorbtive capacity

24
Q

What are the metabolic effects of coeliac disease?

A

Malabsorbtion of sugars, fats, amino acids, water and electrolytes
Reduced inntestinnal hormone production leads to reduced pancreatic secretion and bile flow (CCK) leading to gallstones

25
Q

What does malabsorbtion of fats lead to?

A

Steatorrhea

26
Q

What is stearorrhea?

A

The excretion of abnormal quantities of fat with the faeces owing to reduced absorption of fat by the intestine.

27
Q

What are the effects of malabsorbtion?

A
Loss of weight
Anaemia (Fe, Vit B12, Folate) 
Abdominal bloating
Failure to thrive
Vitamin deficiencies
28
Q

What are other complications (excluding malabsorbtion) of coeliac disease?

A

T-cell lymphoma
Increased risk of small bowel carcinoma
Gall stones
Ulcerative-jejenoilleitis