Lecture 7 Flashcards
What does disease affecting crypts of Lierberkuhn cause
Severe mucosal loss
Does the GIT have a large surface area
Yes
What happens when the GIT is damaged
Loss of large amounts of protein, fluid and electrolytes
List the defence mechanisms of the intestinal tract
- Normal bacterial flora
- Gastric and intestinal secretions
- Bile and pancreatic secretions
- Peristalsis
- Epithelial turnover
- Antibodies Ig A and M
- Gut associated lymphoid tissue
- Kupffer cells of liver
What are the pathogenic mechanisms of diarrhoea
- Malabsorption
- Hypersecretion
- Exudation
- Hypermotility
What sort of diarrhoea does malabsorption cause
Osmotic esp in small intestine
What is hypersecretion by and what does it cause
By structurally intact mucosa
Efflux of fluid and electrolytes
What does exudation cause
Increased permeability and protein losing enteropathy
What are the consequences of acute gastro-entero-colitis
- Dehydration
- Acid base disturbances
- Electrolyte imbalances
- Hypovolaemic shock and death
With dehydration what does hypovolaemia cause
Reduced tissue perfusion
What is metabolic acidosis
Tissue hypoxia -> anaerobic glycolysis -> ketoacidosis and there is a bicarbonate loss from diarrhoea
What is metabolic alkalosis from
HCl loss from vomiting
What does the electrolyte imbalance cause
Decreased neuromuscular control of myocardium
What can be caused with chronic diarrhoea
Hypoproteinaemia
What is hypoproteinaemia caused by
- Loss of protein and other nutrients
- Weight loss
- Oedema, bottle jaw, anasarca
What is atresia
Occlusion of lumen due to abnormal development - segment of intestine occluded or completely missing
What is Meckel’s diverticulum
Blind ended sac near jejunum-ileum junction
What is a megacolon
Large colon, usually faecal filled absent or damaged colonic innervation
What can cause intestinal obstruction
- Foreign bodies
- Impaction
- Strictures
- Enteroloths
What are some examples of foreign bodies
Obstruction +/ or toxicosis
Linear foreign bodies
Phytobezoars, trichobezoars
What are some examples of impaction
Feed
Sand
Nematodes
What does trichobezoar cause
Generally incidental finding but may cause partial/complete obstruction
What is trichobezoar
Composed of hair
What is intussusception
A segment of intestine telescoped into the immediately distal segment
What is intussusception associated with
Intestinal irritability and hyper motility
What does intussusception cause
Obstruction of intestine
Whta is paralytic ileus
Non-mechanical hypo motility - intestine is refractory to nerve discharge
What does paralytic ileus result in
Functional obstruction
What can cause paralytic ileus
Intestinal manipulation at surgery Anaestheia/drugs Peritonitis Toxaemia Shock Electrolyte imbalances Uraemia Tetanis
What is the process of intestinal hernias
Herniation -> incarceration -> strangulation
What is internal herniation
Displacement though a normal or pathological foramen in the abdominal cavity
What is an external herniation
A pouch (sac) of peritoneum penetrates outside abdominal cavity Protrusion of intestines out through abdominal wall
What is included in the small intestine
Suodenum, jejnum, ileum
What is included in the large intestine
Colon, caecum
What is steatorrhoea
Yellow faeces due to excessive fat
What are M cells good for
The uptake of antigens
