Pathology of the Alimentary Tract III Flashcards
What is the definition of Intestine stenosis?
intestine contains areas of blockage that prevents food moving through
What is intestinal atresia?
Intestine is closed or absent
What is megacolon?
abnormal dilation of the colon
What is Aganglionosis?
a blockage of the large intestine due to improper muscle movement in the bowel.
What can cause intestinal stenosis?
Compression via granulomas, abscesses, tumours
What is atresia coli?
colon is occluded
What is atresia ani?
anus is occluded
what is segmental atresia?
a segment of the bowel is either entirely missing or completely occluded due to a lack of epithelila development
What are the general causes of atresia?
malpositioning of the foetus, mechanical lesion to the vessel in a portion of the gut , vascular accidents
What is the usual cause of congenital megacolon?
A developmental lack of ganglion cells due to the myenteric plexus
What is the usual cause of acquired megacolon?
Can be secondary to atresia ani
* damage to the colonic innervation
What is the cause of agangliosis?
Congenital absence of ganglion
cells from the myenteric
(Auerbach’s) plexus or
submucosal (Meissner’s) plexus
more common in overo foals
What can cause generalised obstruction and impaction?
- foreign bodies
- copper/ zinc toxicosis
- lead (common in cows ingesting batteries)
- linear foreign bodies
*
What three things can cause heavy impactions in horses?
- heavy ascarid infections (ascardid is a parasite)
- poor dentition (diets with high roughage)
- ingested sand accumulating in the colon
What can cause narrowing of the intestinal lumen in horses?
can occur from fibrosis
What is Intussusception?
One segment of intestine becomes telescoped into the immediately distal segment of the intestine
What are the consequences of intestinal obstruction and impaction?
Death from -
* Toxemia
* Starvation
* Dehydration and emaciation
Gross lesions
* distended abdomen
* dilated bowel
* perforation
What is the Intussuscipiens and Intussusceptum?
the *trapping *segment and the trapped segment
What does causes Intussusception
- altered mobility/ peristalsis
- peritonitis/enteritis
- foreign bodies/ masses
- idiopathic
What is an Eventration?
protrusion of the intestine through the abdominal wall or diaphragm
What is a volvulus?
Twisting of the intestine along its mesenteric axis
What is a torsion?
rotation of a tubular organ along its long axis
How does strangulation by pedunculated lipomas occur?
Pedunculated lipomas wrap around the intestinal mesentry or the bowel
they may rotate around their pedicle
usually in horses
What is an internal herniation?
Formed through a normal or pathological foramen in the abdominal cavity
- e.g the Foramen of Winslow which is between the greater peritoneal sac
