Pathology of the alimentary tract III Flashcards
What are the congenital abnormalities of the intestine?
- stenosis
- atrisia
- megacolon
- aganglionosis
What is stenosis?
- narrowing of the intestinal lumen
- caused by compression by tumous, granulomas, abscesses
- or hyperplasia of intestinal mucosa
What is atresia?
- occlusion of the intestinal lumen - caused by an anomalous development of intestinal wall
- A.coli
- A.ani
- Segmental atresia - if a segment of the bowel is missing or completed occluded - due to lack of ep development between the 2 continuous parts
Causes of atresia?
- malpositioning of foetus
- mechanical lesion to vessel in part of gut
- vascular accidents
- ischaemia
What is Megacolon?
- large, faeces filled colon
- congenital - fewer ganglion cells in mesenteric matrix
- acquied - A.ani, damage to innervation
What is Aganglionosis>
- congenital lack of ganglion cells in enteric plexus
What is Merkels diverticulum persistence?
- remnant of the omphalomesenteric duct
- should disappear in 1st trimester
What can block the intestine?
- physical
- foreign bodies
- enteroliths
- impaction
- stenosis
- Functional
- grass sickness
- paralytic ileus
- feline dysautonomia
How do obstructions cause death?
- toxaemia
- shock
- dehydration
- starvation
Gross lesions due to obstructions?
- distended abdomen
- dilation proximal to blockage
- empty after/ collapsed
- perforation
- congested/ infarcted area
What are the classifications for displacement of the intestine?
- eventration
- displacement
- strangulation
- mesenteric volvulus
- intrussusception
- hernias
What is Intussesception and what are the causes?
- telescoping of the intestine
- intussuscepten - trapping segment
- intussusceptum - trapped
- causes - altered motility, peristalsis, foreign body, peritonitis, enteritis
What herniations occur?
- internal
- Foramen of Winsloe
- mesenteric tears
- retrosplenic ligaments
- External
- scrotal
- umbilical
- perineal
- diaphragmatic
What is inflammation of the SI and rectum called?
SI = enteritis
rectum = proctitis
What part of the villi do enteritis causing viruses target?
- rotavirus - upper 2/3
- coronavirus - middle and tip
- parvo - botoom - crypts, peyers patches
- BVDV - all + PPs
How does rotavirus cause atrophic enteritis?
- faecal-oral infection
- viral replication
- necrosis and sloughing of epithelium
- release of viral particles
- loss of enterocytes
- villous atrophy
- impaired absorption and digestion
- diarrhoea
Enteritis (atrophy to necrotising) - what causes it?
- parvovirus
- panleukopaenia (cats)
- causes intestinal segmental lesions
- crypt necrosis
- villous atrophy hyperplasia
- lymphoid necrosis
- bone marrow necrosis
- fatal cerebellar necrosis
What causes haemorrhagic/ necrotising enteritis?
- C.perfringens
- sudden death in well nourished animals
What is lymphoplasmacytic enteritis?
- lymphoplasmacytic fluid in lamina propria
- dog/cat
- villous atrophy, crypt dilation, ep necrosis
- lymphoma
WHat is granulomatous enteritis caused by?
- Johne’s disease
- granulomatous inflam - lamina propria
- cerebroid appearance of mucus
What is fibrino-necrotising enteritis?
- salmonellosis
- bacterial toxins -> vasculitis -> focal intestinal infarcts -> button ulcers
