Intestine Flashcards
What are 5 morphologic classifications of inflammatory intestinal disease?
What are 5 morphologic classifications of inflammatory intestinal disease?
- Hemorrhagic enteritis (Clostridium)
- Fibrinous, Necrotic & Fibrinonecrotic enterocolitis (Salmonella)
- Ulcerative enterocolitis (ischemia, BVD)
- Suppurative or pyogranulomatous enterocolitis (Rhodococcus)
- Proliferative or hyperplastic enteritis (Coccidiosis)
- Granulomatous enterocolitis (Johne’s)
When is hemorrhagic enteritis mostly commonly seen? (3)
When is hemorrhagic enteritis mostly commonly seen? (3)
- Acute chemical intoxications (such as arsenic posoning)
- Bacterial diseases (Clostridial & Campylobacter infections)
- Actue coccidiosis
Example of fibrinous, necrotic, and fibrinonecrotic enterocolitis
Example of fibrinous, necrotic, and fibrinonecrotic enterocolitis
Salmonella, Swine dysentery, BVD
**Example of Ulcerative enterocolitis **
**Example of Ulcerative enterocolitis **
Hog Cholera
Ischemia
BVD
**Example of suppurative or pyogranulomatous enterocolitis **
**Example of suppurative or pyogranulomatous enterocolitis **
Strep. equi
Corynebacterium equi (Rhodococcus or Actinomyces)
**Example of proliferative or hyperplastic enteritis **
**Example of proliferative or hyperplastic enteritis **
Coccidiosis
Lawsonia intracellularis (pigs)
Campylobacter (hamsters)
Example of Granulomatous enterocolitis
Example of Granulomatous enterocolitis
Johne’s disease
Equine granulomatous enteritis
What form of Escherichia coli infection can cause abnormal intestinal function without producing any morphologic changes in the intestinal mucosa?
What form of Escherichia coli infection can cause abnormal intestinal function without producing any morphologic changes in the intestinal mucosa?
Septicemic colibacillosis
(Intestinal lesions and diarrhea are NOT always present because organisms can penetrate into circulatory system via the umbilicus, intestinal and respiratory tracts)
**Describe septicemic colibacillosis gross lesions **
**Describe septicemic colibacillosis gross lesions **
- Minimal, if death mediated largely by effects of bacterial endotoxin
- When sufficient time for antemortem localization and an inflammatory reaction to occur -
- Acute fibrinous or fibrinopurulent polyarthritis
- Panophthalmitis
- Peritonitis
- Meningitis
- Acute pneumonia
Describe septicemic colibacillosis mechanism of action
Describe septicemic colibacillosis mechanism of action
Describe septicemic colibacillosis histopathology
Describe septicemic colibacillosis histopathology
Describe enterotoxigenic colibacillosis gross lesions
Describe enterotoxigenic colibacillosis gross lesions
Similar to viral enteritis? except villous lesions not usually seen histologically (except in pigs)
**Describe enterotoxigenic colibacillosis mechanism of action **
**Describe enterotoxigenic colibacillosis mechanism of action **
Bacteria adhere to enterocyte surfaces via pili and production of heat-labile (LT) and heat-stable (HT) enterotoxins. Enterotoxins increase chloride and bicarbonate movement into lumen with concurrent water movement -> Secretory diarrhea
Describe enterotoxigenic colibacillosis histopathology
Describe enterotoxigenic colibacillosis histopathology
Describe enteropathogenic colibacillosis gross lesions
Describe enteropathogenic colibacillosis gross lesions
Effaced microvilli
Villous atrophy & fusion
**Describe enteropathogenic colibacillosis mechanism of action **
**Describe enteropathogenic colibacillosis mechanism of action **
Slide
E. coli binds to surface of enterocytes on microvilli > bacterium injects the translocation intimin receptor into host cell > Host cell signalling pathways subverted > Major host cell cytoskeletal changes result in pedestal formation where bacterium attaches
Notes
Bacteria attach via pili and produce Shiga-like cytotoxin to efface microvilli
**Describe enteropathogenic colibacillosis histopathology **
**Describe enteropathogenic colibacillosis histopathology **
Effaced microvilli
Villous atrophy and fustion in ileum and jejunum
(also damage colonic and cecal epithelium)
Colibacillosis Summary
1) Septicemic
2) Diarrheal
a. Enterotoxigenic
b. Enteroinvasive
c. Enteropathogenic
3) Enterotoxemic
(not a study question)
Colibacillosis Summary
1) Septicemic - Endotoxin
2) Diarrheal
a. Enterotoxigenic - Suface adhesion w/ enterotoxin production
b. Enteroinvasive - Invade epithelial cells (Shiga toxin), necrosis
c. Enteropathogenic - Attaching & Effacing microvilli
3) Enterotoxemic - Exotoxin
How does Salmonella cause enteric disease (pathogenesis)?
How does Salmonella cause enteric disease (pathogenesis)?
Salmonella, in membrane-bound vacoules, enters intestinal epithelial cells and are deposited into lamina propria
Proliferate in macrophages and enter blood
Bacteria killed in phagocytes release endotoxins, enterotoxins or cytotoxins
Induce necrosis, erythema and edema
What portions of the villi are affected by:
Rotavirus
Coronavirus
Parvovirus
What portions of the villi are affected by:
- *Rotavirus -** Tip of villi
- *Coronavirus -** Upper & Middle
- *Parvovirus -** Crypt
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Parvovirus
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Parvovirus
Portion of the villus - Crypts (so villi shorten)
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
** Coronavirus**
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Coronavirus
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Rotavirus
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
**Rotavirus **
**List at least three types of conditions that can lead to protein loss and hypoalbuminemia from the GI tract **
**List at least three types of conditions that can lead to protein loss and hypoalbuminemia from the GI tract **
Increased permeability of mucosal epithelium (chronic enteritis)
Exudation (increased epithelial or capillary permeability)
Malabsorption
Disease of what other two organs (other than the GI tract) can cause hypoproteinemia?
Disease of what other two organs (other than the GI tract) can cause hypoproteinemia?
Kidney & Liver
(class google doc)
Define the term “diarrhea”
Define the term “diarrhea”
Frequent passage of soft, unformed or watery feces
One or more of the following are usually increased: Frequency, Fluid, Volume
What are the main pathophysiologic mechanisms responsible for diarrhea?
What are the main pathophysiologic mechanisms responsible for diarrhea?
Increased mucosal permeability
Mucosal hypersecretion
Exudation
Malabsorption and Maldigestion
**Define intusussception **
Define intusussception
Condition where one intestinal segment becomes telescoped into the immediately distal segment of intestine** **
Trapped segment - Intussusceptum
Surrounding portion - Intusscipiens
Define volvulus
Define volvulus
Twisting of the intestine upon the mesentery
**Define torsion **
Define torsion
Rotation of tubular organ on its long axis
Define hernia
Differentiate between incarcerated and strangulated
Define hernia
Displacement of intestine through a normal or pathologic foramen in the peritoneal cavity
Differentiate between incarcerated and strangulated
Incarcerated - herniated segment becomes permanently entrapped due to venous stasis promoting edema and increased fluid movement in intestinal lumen
Strangulation - pressure placed on the venous and arterial supply to intestine produces infarction
**What are pathophysiologic consequences of intussusception **
**What are pathophysiologic consequences of intussusception **
Congestion > Hemorrhage > Necrosis (Ischemia)
What are pathophysiologic consequences of volvulus
What are pathophysiologic consequences of volvulus
Luminal obstruction and ischemic injury
What are pathophysiologic consequences of torsion?
What are pathophysiologic consequences of torsion?
Luminal obstruction and ischemic injury
What are pathophysiologic consequences of hernia (incarcerated vs. strangulated)?
What are pathophysiologic consequences of hernia (incarcerated vs. strangulated)?
**What is a strangulating lipoma and where does it originate? **
**What is a strangulating lipoma and where does it originate? **
Pedunculated lipoma strangulates the mesentery and/or intestine
Most common at the small/large intestine connection (class google doc)
In what species does a strangulating lipoma most commonly occur?
In what species does a strangulating lipoma most commonly occur?
Horses
What is the clinical significance of a strangulating lipoma?
What is the clinical significance of a strangulating lipoma?
Results in infarction
What pathologic processes in the digestive tract are associated with maldigestion and malabsorption? Give examples of diseases
What pathologic processes in the digestive tract are associated with maldigestion and malabsorption? Give examples of diseases
- Reduced mucosal surface area (rotavirus, parvo, coronavirus)
- Infiltration of lamina propria by macrophages, neoplastic cells or amyloid (Johne’s, equine granulomatous enteritis, neoplastic disease: intestinal lymphoma, intestinal amyloidosis)
- Loss of mucosal brush border enzymes (lactase, maltase, sucrose) or transport mechanisms (lactase deficiency, genetic mutations)
- Lympathic obstruction (neoplasms, tuberculosis)
What are the common infectious causes of diarrhea in calves?
Diagnosis?
What are the common infectious causes of diarrhea in calves?
- Rotavirus infection
- Coronavirus (winter dysentery)
- pathogenic E. coli
- Cryptosporidia
- BVD
- Malignant catarrhal fever?
Diagnosis - viral PCR, fecal EM and bacteriologic isolation, gene sequencing, serotyping
What bacterial agent can produce gastric mucosal hyperplasis in dogs?
What bacterial agent can produce gastric mucosal hyperplasis in dogs?
What protozoal agent of goats produces enteritis with marked epithelial hyperplasia?
What protozoal agent of goats produces enteritis with marked epithelial hyperplasia?
Coccidiosis
Give 4 examples of obstructive GI diseases. What pathophysiological characteristic do they have in common?
Give 4 examples of obstructive GI diseases. What pathophysiological characteristic do they have in common?
Intussusception, Volvulus, Torsion, Hernia, Mesenteric pedunculated lipoma, Segmental atresia, Megacolon, Stricture
Foreign bodies, enteroliths, impacted ingesta, parasitic impaction (class google doc)
**What are some of the predisposing factors in the development of intussusception? **
**What are some of the predisposing factors in the development of intussusception? **
Irritation & Hypermotility
Foreign bodies, polypoid tumors, parasitic nodules, parasite infections, viral/enteritis, following surgical handling of intestines, idiopathic
Differentiate intussusceptum vs. intussuscipiens
Differentiate intussusceptum vs. intussuscipiens
Intussusceptum - trapped segment
Intusscipiens - enveloping/surrounding segment
**Reduced mucosal surface area is one process in the digestive tract associated with maldigestion and malabsorption - **
What are specific causes of this pathology?
Reduced mucosal surface area is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?
Viral enteritis with villous atrophy
Examples:
- Rotavirus
- Parvovirus
- Coronavirus
Infiltration of lamina propria by macrophages, neoplastic cells or amyloid is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?
Infiltration of lamina propria by macrophages, neoplastic cells or amyloid is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?
Chronic inflammatory disease - Johne’s, equine granulomatous enteritis
Neoplastic disease - intestinal lymphoma
Intestinal amyloidosis
**Loss of mucosal brush border enzymes (lactase, maltase, sucrose) or transport mechanisms is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?**
Loss of mucosal brush border enzymes (lactase, maltase, sucrose) or transport mechanisms is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?
Lactase deficiency in humans
Genetic mutations of transport proteins in humans
Lympathic obstruction is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?
**Lympathic obstruction is one process in the digestive tract associated with maldigestion and malabsorption -
What are specific causes of this pathology?**
Neoplastic obstructions of lymphatics: lymphoma, sarcomas, carcinomas
Lymphadentis with obstruction: tuberculosis
Lymphangiectasis
What methods would you use to confirm diagnosis in calves with diarrhea? (5)
**What methods would you use to confirm diagnosis in calves with diarrhea? **
Supportive procedures are essential for accurate diagnosis in most cases. Mixed infections are common.
- Viral PCR
- Fecal EM
- Bacteriologic isolation
- Gene sequencing
- Gene serotyping
**How do you diagnose rotavirus infection in calves? **
**How do you diagnose rotavirus infection in calves? **
**How do you diagnose coronavirus in calves? **
**How do you diagnose coronavirus in calves? **
**How do you diagnose cryptosporidia in calves? **
**How do you diagnose cryptosporidia in calves? **
**How do you diagnose pathogenic E. coli in calves? **
**How do you diagnose pathogenic E. coli in calves? **
How do you diagnose Bovine virus diarrhea?
How do you diagnose Bovine virus diarrhea?
**Define atresia and stenosis. Where do they commonly occur? **
**Define atresia and stenosis. Where do they commonly occur? **
Atresia - a segment of bowel is either entirely missing or completely occluded
Jejunum, colon, anus
Stenosis - decreased diameter
Ileum (google doc)
