Intestinal pathology

Question 1

clinical presentation - abdominal pain

Answer 1

acute or chronic

Causes - Torsion, Obstruction (internal/external), Rupture

Question 2

pedunculated lipoma

Answer 2

tumour attached by a small stalk
the stalk wraps around intestine and cuts off blood supply
red/black appearance of intestine

Question 3

consequences of obstruction of the upper intestinal tract

Answer 3

Presentation generally acute and severe 
Fluid and gas above obstruction 
vomiting 
metabolic alkalosis (loss of acid in vomitus) 
dehydration 
reduced renal flow and resultant uraemia

Question 4

consequences of obstruction of the lower intestinal tract

Answer 4

Presentation less acute than upper (vomiting reduced + fluid resorption proximal to obstruction delays serious distension)
Pressure -ulceration and infarction, haemorrhage/peritonitis
metabolic acidosis due to dehydration + catabolism of fat + muscle (producing keto acids)

Question 5

acute diarrhoea - causes

Answer 5

Often involves infectious disease 
Viruses 
Bacteria
Endoparasites 
Protozoa

Question 6

5 mechanisms of pathogenesis of diarrhoea

Answer 6

Altered epithelial cell transport (secretory diarrhoea) 
Altered structure / permeability 
Osmotic effects 
Altered motility 
Damage to colonic mucosa

Question 7

consequences of acute diarrhoea

Answer 7

Loss of water - Dehydration, Haemoconcentration, Hypovolaemic shock
Loss of ions - Hypokalaemia, Metabolic acidosis

Question 8

chronic diarrhoea +/- weight loss - causes

Answer 8

Chronic enterocolitis (inflammatory bowel disease)
Lymphangiectasia (dilation of lymph vessels)
Endoparasitism
Neoplasia
Grass sickness

Question 9

maldigestion - liver - define

Answer 9

decreased bile secretion or obstruction to biliary outflow

Question 10

maldigestion - pancreas - define

Answer 10

decreased enzymes (exocrine pancreatic insufficiency): 
major cause of intraluminal maldigestion

Question 11

malabsorption - intestine - define

Answer 11

decreased surface area for adsorption of nutrients

Question 12

Bacterial overgrowth and maladsorption - causes

Answer 12

decr gastric acidity
motility disturbances
obstruction of intestine
immunodeficiency
cachexia (weight loss)
gastrectomy
colonicjejunal fistula

Question 13

protein losing enteropathy

Answer 13

Main protein lost is albumin. Loss exceeds ability of liver synthesis and leads to hypoalbuminaemia

Question 14

protein losing enteropathy - effects

Answer 14

Incr permeability to plasma proteins - lost to intestinal lumen
Chronic inflammation - lymphatic blockage
decr plasma osmotic pressure - oedema and ascites

Question 15

inflammatory bowel disease

Answer 15

persistent intestinal inflammation

eosinophilic or lymphoplasmacytic enteritis

Question 16

endoparasitism - effects

Answer 16

Maladsorption (e.g. cyathostominosis) 
Obstruction (e.g. ascariasis) 
Vascular compromise (e.g. large strongyle disease)

Question 17

grass sickness - acute presentation

Answer 17

Nasogastric reflux and oesophageal ulceration

Gastric dilation and rupture

Question 18

grass sickness - subacute to chronic

Answer 18

Weight loss 
Muscle tremors 
Rhinitis sicca (dry membranes)
Dysphagia 
Patchy sweating 
Constipation 
Large colon impaction