Intestine Flashcards
1
Q
List 6 types of epithelial cells in the Intestine
A
- Enterocytes
- Crypt epithelial cells
- Goblet cells
- Paneth’s cells
- Enterochromaffin cells
- M cells
2
Q
List 4 types of mesenchymal cells in the Intestine
A
- Thelio-lymphocytes
- Neutrophils
- Eosinophils
- Globule luekocytes
3
Q
Three functions of the intestine:
A
- Absorption
- Digestion
- Secretion
4
Q
The villi of the small intestine greatly increase the absorptive area. They are lined by __________ cells, and have an enzymatically rich brush border consisting of the _________ (a filamentous layer) and ______.
A
- columnar epithelial cells
- glycocalyx
- Microvilli
5
Q
The large intestine’s main functions are (2)
A
- Resorption of fluids
- Lubcrication via goblet cells
6
Q
Crypt epithelial cells migrate up the villi, undergo matration, and eventually shed at the tips into the lumen. This takes about how many days? Is the turnover rate faster or slower in the large bowel?
A
- 2-4 days
- Slower in the large bowel
7
Q
Pathogenesis of Diarrhea
Malabsorption - explain process
A
- Nutrients are not absorbed in small intestine
- Sugars and other nutrients pass to large intestine
- Sugars are split by bacteria in large intestine into osmotically active particles
- Water and other solutes are held in large intestine
- Excreted as diarrhea
8
Q
Gross lesions of malabsorption induced by viral enteropathy
A
- Neonatal animals
- Thin
- Milk curd in stomach
- Thin walled small intestine
- Watery content of colon
- Lacteals empty
9
Q
Several viruses selectively affect the villus absorptive epithelium:
How does the rotavirus do it?
A
- Destroys cells on tip of the villus
- Lose mature enzyme producing and absorptive cells
- Villus atrophy develops
10
Q
Epizootic diarrhea of infant mice, acute gastroenteritis of piglets, neonatal calf diarrhea, and human infantile gastroenteritis are all diseases caused by this type of virus:
A
rotavirus
11
Q
Several viruses selectively affect the villus absorptive epithelium:
How does the coronavirus do this?
A
- Destroys epithelial cells in the middle portion of the villus
- Lose mature enzyme producing and absorptive cells
- Villus atrophy develops
- May infect colonic epithelium
12
Q
Transmissible gastroenteritis in pigs, porcine epidemic diarrhea, neonatal calf diarrhea, turkey bluecomb disease virus are all diseases caused by this type of virus:
A
Coronavirus
13
Q
Several viruses selectively affect the villus absorptive epithelium:
How does parvovirus do this?
A
- Destroy cypt epithelium
- Produces viremia first
- Infects mitotically-active cells of the intestinal crypt epithelium and lymphoid tissues
- Crypts are destroyed. Villus atrophy developes
- Loss of mucosal epithelium expose lamina propria and allows bile to stain inner surface of itnestine
14
Q
Feline panleukopenia virus and mink enteritis virus are examples of this type of viral disease.
A
Parvoviral
15
Q
Feline panleukopenia virus:
- How do bacteria affect the turnover rate of absorptive epithelial cells? And how does this affect the viral infection?
- What is the difference between conventional and specific pathogen-free cats and germ-free cats?
A
- Lesions are most severe in conventional and specific pathogen-free cats, and least severe in germ-free cats
- Bacteria and bacterial products increase the turnover rate of the absorptive epithelial cells. This stimulates crypt cell replication which in turn favors viral replication in the intestines of conventional and SPF cats.
- The intestinal epithelial cell turnover rate is 2-4 days in conventional animals, and 7-10 days for germ-free animals
16
Q
Several viruses selectively affect the villus absorptive epithelium:
How does the BVD virus do this?
What are the lesions?
A
- Destroys crypt epithelium
- Infects mitotically active cells of the intestine and lymphoid system
- Petechial hemorrhages in spiral colon
17
Q
BVD virus is what type of virus? Family?
RNA or DNA virus?
A
- Pestivirus in family Flaviviridae
- RNA virus
18
Q
How is radiation exposure and radiomimetic drugs identical to parvoviral infection? What is the main difference?
A
- They destroy the mitotically-active cell population and produce intestinal lesions that are identical to parvoviral infection
- Except that no inclusion bodies are formed
19
Q
Cryptosporidiosis causes malabsorption of the small intestine.
- Agent?
- Infests _______ of the small itnestine
- Infects ______ hosts
- Produces thick _____ content of small and large itnestines
- Prevents ______ of nutrients
A
- Cryptosporidium parvum
- brush border
- immunodeficient
- mucoid
- absorption
20
Q
In hypersecretion, _____ (old/neonatal) animals are affected. Intestinal epithelium secretes _____ and ______ into lumen.
A
- Neonatal
- Water
- Electrolytes
21
Q
Enterotoxigenic E. coli cause diarrhea due to what kind of pathogenesis?
Describe how they do this.
A
- Hypersecretion
- Enterotoxigenic E. coli attach to enterocyte via pilus
- Produce toxin that activates adenyl cyclase
- This causes intestinal epithelium to secrete water and electrolytes into the lumen
22
Q
Lesions of Colibacillosis:
- Small intestine?
- Thickness of wall?
- Lacteals?
- Intestinal epithelium?
A
- Gross - fluid filled small intestine
- Normal thickness of wall
- Lacteals full
- Intestinal eptihelium is undamaged
23
Q
Exudation
____ - losing enteropathies
A
protein
24
Q
Explain pathogenesis of diarrhea caused by exudation
A
- Protein-losing enteropathies - proteins are lost into the gut lumen
- Increased shedding of mucosal epithelial cells
- effusion of plasma proteins
- Altered permeability of lymphatics, blood vessels or tight junctions between epithelial cells - non selective loss of plasma proteins
25
Intestinal lymphangiectasia, Chronic Inflammatory Bowel Disease, and Intestinal lymphosarcoma are all causes of enteric \_\_\_\_\_-\_\_\_\_
Enteric protein-loss (diarrhea due to exudation)
26
The most commonly reported cuase of protein-losing enteropathy is?
Canine Intestinal Lymphangiectasia
27
Canine Intestinal Lymphangiectasia
* Symptoms
* How do dogs get it?
* Cause?
* Lesions?
* Diarrhea, steatorrhea, hypoproteinemia, ascites
* Congenital or acquired secondarily to lymphatic obstruction
* Usually idiopathic
* Thickened intestinal mucosa, dilated lymphatics and lacteals
28
Hypermotility
* Increased rate, intensity, or frequency of peristalsis
* Not usually a primary mechanism
* Causes decreased mucosal contact time
* May not have a morphologic change
29
*Clostridium perfringens* type C. and *Clostridium difficile* cause severe ______ enteritis via _______ cytotoxicity.
* Severe necrohemorrhagic enteritis
* Direct toxin-mediated cytoxocity
30
Clostridial Enterotoxemia
* Agent
* Occurs in pigs under ____ days of age
* what toxin causes necrosis of epithelium?
* mortality?
* What happens to stomach and intestine?
* *Clostridium perfringens* type C
* 7
* Exotoxin
* High death loss in pigs of susceptible litters
* Distension of stomach with milk causes hypomotility of gut and development of anaerobic environment in intestine.
* Segmental hemorrhage in jejunum
* Mucosa of segments on small intestine may be covered by tenacious tan friable exudate
* Necrosis of epithelial lining with fibrinous exudate and intense infiltration by neutrophils.
31
*Clostridium perfringes* type D
* What animals does it affect?
* How do they acquire it?
* Symptoms?
* This agent causes endothelial cell damage. What results from this?
* Sheep, goats, calves
* Sudden change in diet to easily digested carbohydrates
* Sudden death
* Overgrowth of organism in small intestine
* Endothelial cell damage (fibrinoid necorsis):
* Multisystemic hemorrhages
* Pericardial effusion
* Mild gastroenteritis
* Bilateral symetrical encephalmalacia
32
*Clostridium perfringes* type D infection in sheep is also called \_\_\_\_\_
Puply Kidney Disease
33
Canine Hemorrhagic Gastroenteritis
* Agent suspected?
* What kinds of dogs are affected (breeds/age)
* Symptoms
* Can death result?
* Lesions?
* What part of the intestinal epithelium is spared?
* *Clostridium perfringes* type E
* Toy and miniature breeds 2 years or less
* Depressed, diarrhea, vomiting, blood at anus
* Life threatening
* Hemorrhagic necrosis in mucosa of GI tract and numerous clostridia in intestinal debris
* Crypts are spared
34
Tyzzer's Disease:
* Agent
* What animals does it affect?
* Lesions
* Microscopic lesions
* *Clostridium piliformis* (*Bacillus piliformis*)
* Rodents - guinea pigs, hamsters, gerbils; and lagomorphs (rabbits)
* Less commonly seen in rats, mice, cats, dogs, and horses
* Enterocolitis and necrotizing hepatitis
* "hay stack" arrangement of filamentous organisms in silver or giemsa stained sections
35
Tyzzer's Disease is also called _____ in rodents and lagomorphs.
Wet Tail
36
*Clostridium difficile* is an opportunistic infection that is associated with disruption of normal flora and overgrowth.
* Treatment
* Produces what exotoxins? What test can detect these exotoxins?
* What does it cause in horses, foals, baby pigs, lab animals, primates (and humans), and dogs?
* Antibiotics
* Produces A and B exotoxins - detected by ELISA
* Necrotizing enterocolitis in horses (colitis X?)
* Hemorrhagic necrotizing colitis in foals
* Mesocolonic edema and typhylocolitis in baby pigs
* Enteritis in lab animals
* Pseudomembranous colitis in primates, including humans
* Shed by dogs
37
Numerous agents cause damage of structural integrity of intestinal epithelial cells leading to local inflammation and cytotoxic damage.
How does enteroadherent E. coli do this?
What are the lesions?
* Via intimate contact between pathogen and brush border - attaching and effacing
* Enteroadherent E. coli attach to absorptive epithelium of intestine effacing the microvilli
* Also attaches to gallbladder epithelium
* Intestine is dilated and fluid filled
* Causes exfoliation and villus atrophy
38
Numerous agents cause damage of structural integrity of intestinal epithelial cells leading to local inflammation and cytotoxic damage.
* How do Salmonella sp. do this?
* Symptoms?
* Lesions
* How is it transmitted?
* Invasion of intestinal epithelium - M cells serve as a portal of entry
* Hosts may be inapparent carriers or may have septicemia, acute enteric disease, or chornic enteritic disease
* Salmonellosis may cause enterocolitis = thickening of wall of intestine, and mesenteric lymph nodes may be enlarged, mucosal surface may be covered by tenacious friable diphtheritic membrane
* Paratyphoid nodules in liver and button ulcers in colon may be seen
* Ingested in contaminated feedstuff, from fomites, or contact with infected animals
39
*Rhodococcus equi* in foals localizes in _________ in the small bowel and in _______ in the large bowel and related \_\_\_\_\_\_.
* peyer's patches
* lymphoid follicles
* related lymph nodes
40
Ulcerative enteritis is a ____ infection in the digestive tract. It is often ______ to some other cause. Commonly affects ______ birds, and _____ (type of bird) commonly get it. The agent is \_\_\_\_\_\_\_\_\_. Birds become _______ and weak and die.
There are multiple areas of necrosis and ulceration in the intestines. Ulcers may perforate and cause \_\_\_\_\_\_.
* clostridial
* secondary
* gallincacious
* Quail
* *Clostridium colinum*
* emaciated
* peritonitis
41
Coccidiosis
* What two agents infect all species of domestic animals and fowl?
* Infects these types of cells \_\_\_\_\_, causing \_\_\_\_\_
* Microscipic lesions?
* *Eimeria* sp. and *Isospora* sp.
* Infects enteroyctes, destroys them causing inflammation, villus atrophy, and hemorrhage - reddened hemorrhagic mucosa and bloody diarrhea
* Microscipically see inflammation of mucosa in infected areas of the itnestine and usually see the organism
* Coccidiosis in pigs can result in thickened intestine and mucosa covered by friable tenacious tan exudate
42
* Histomoniasis is also called ______ and is caused by \_\_\_\_\_\_\_.
* Infects what species?
* Agent is carried by _____ which is harbored by \_\_\_\_\_.
* Lesions?
* Blackhead, caused by *Histomonas meleagridis* - protozoan
* Turkeys, chukar partridge, peafowl, chickens
* Carried by cecal worm which is harbored by earthworms
* Typhlitis and hepatitis
* Caseous cecal cores and rount pale spots on liver
43
Proliferative enteritis
* Causes hyperplasia of infected epithelial cells in the ____ and the proximal \_\_\_\_\_.
* Causes _____ in spiral colon.
* Causes ____ in terminal colon.
* Increases ______ material in the ileum.
* Ropy clot in the colon =
* ileum and proximal colon
* hemorrhage in spiral colon
* malena in terminal colon
* Fibronecrotic material
* hemorrhage bowl syndrome
44
Porcine intestinal adenomatosis is a proliferative enteritis and is caused by this agent:
*Lawsonia intracellularis*
45
Define Granulomatous enteritis
Chronic inflammation with macropahges (histiocytes), granulomas, and giant cells.
46
Johne's disease
* Example of ______ enteritis
* Etiology
* Affects these animals
* Pathogen lives in this cell type
* Symptoms/lesions
* Example of granulmatous enteritis
* *Mycobacterium avium* subsp. *paratuberculosis*
* Cattle and other ruminants
* Lives in macrophages
* Affected animals may be emaciated; in cattle see thickened ileum and mesenteric lymph nodes and liquid contents in large intestine; other ruminants usually have only emaciation
* Macrophages (histiocytes), granulomas, giant cells in lamina propria of ileum and in draining lymph nodes
* Acid-fast bacilli in macrophages in lamina propria of ileum
47
Avian tuberculosis
* affects what species?
* Associated with what part of the body?
* Affects older or younger birds?
* Symptoms?
* _____ infection
* Etiologies?
* Can affect any species
* Usually associated with digestive tract
* Older birds
* Emaciation and death
* Granulomatous infection
* *Mycobacterium avium* - wide host spectrium
* *M. genavense*
* *M. tubercuolosis*
* *M. bovis*
48
In histoplasma enteritis, the organism is located where?
Within macropahges of the lamina propria
49
Rhodococcus equi causes?
Equine enteritis
50
Lymphocytic-plasmacytic enteritis and eosinophilic entritis
* Morphologic designators convenient for classifying enteric inflammation without necessarily identifying a specific cause of disease.
* Likely a reflection of an immune mediated response to antigens unknown; bacterial antigens have not been excluded.
51
Swine dysentery:
*Brachyspira hyodysenteriae* results in:
* Mucoid colitis
* Severe bloody diarrhea and high death loss in pigs 50 pounds and up
* Requires multiple factors to become severe disease
52
Equine Monocytic Ehrlichiosis
* Common name
* Etiology?
* Transmission?
* Mortality?
* Symptoms
* Lesions
* Protozoa present in these cells
* Potomac Horse Fever
* *Neorickettsia (Ehrlichia) risticii*
* Proximity of horses to slow moving water - found in trematodes in fresh water snails, carried by mayflied and caddis flies
* 1/3rd of infected die
* Fever, watery diarrhea, depression, dehydration, colic, ventral subcutaneous edema
* Gross changes in colon and cecum, sometimes SI - loss of crypts in LI, collapse of lamina propria; infiltration of lamina propria and submucosa by macropahges
* Protozoa present in macrophgaes
53
Salmon Poisening
* Etiology
* Species affected
* Location
* Transmission
* Symptoms
* Lesions
* Detection?
* Neorickettsia helmintheoca
* Dog and fox
* Pacific northwest
* Consumption of salmonids carrying the fluke *Nanophyetus salminocla* which may harbor ricketssia
* Fever and depression 6 - 8 days eating infected fish, oculonasal discharge, diarrhea, emesis, anorexia
* Acute and fatal hemorrhagic granulomatous enterocolitis
* Splenolymphadenopahty - swollen tonsils, spleen, lymph nodes
* Hemorrhage and necrosis in GALT - trematodes embedded in intestinal mucosa
* Macropahge infiltration of affected tissues and contain elementary bodies vissible with Giemsa or Gram's stain
* Detect fluke ova in fecal smear
54
Elokoman Fluke Fever
* Agent
* location
* Animals affected
* Lesions?
* *Neorickettsia elokominica*
* Limited range in SE WA
* Canids, bears, raccoons, ferrets
* Similar lesions to salmon poisoning
55
Hemorrahgic Enteritis caused by an adenovirus affects:
and leads to:
* Turkeys 6 - 8 weeks of age
* hemorrhage in intestines and necrosis of lymphoid tissue
56
Transmural intestinal infarction results from....
sudden occlusion of an artery or vein
57
Mucosal or mural infection results from ischemic injury related to \_\_\_\_\_
hypoperfusion
58
Intestinal infarction is most common in what part of the intestine, and why?
small intestine because it is totally dependent on its mesenteric vessels
(the colon has some collateral circulation)
59
In an intestinal infarction, typically, hemorrhage and necoris involes the full thickness of \_\_\_\_\_\_\_
one segment of the gut
60
In arterial occlusions in the intestine, the demarcation from the normal bowel is usually _____ defined.
sharply
61
Three causes of occlusive vascular disease
1. Arterial thrombosis
1. Verminous thromboembolic anterior mesenteric arteritis in the horse
1. Strongylus vulgaris
2. Venous thrombosis
3. Mechanical compression - volvulus, intussusception, strangulated hernia, intestinal adhesions, pedunculated lipoma (horse)
62
Mucosal or Mural Infarction is a hemorrhagic \_\_\_\_\_\_\_\_.
It may be multifocal or continuous and is widely distributed. Ischemic injury apepars to relate to ______ damaging only the _____ layers while sparying deeper leveles of the ____ and \_\_\_\_.
* gastroenteropathy
* hypoperfusion
* inner
* muscularis
* serosa
63
atresia
failure of development of a segment
64
Megacolon
* Define
* Seen in:
* Congintal form lack \_\_\_\_
* Large feces-filled colon
* Seen in pigs, dogs, overo foals
* Myenteric plexuses
65
Impactions, enteroliths, strictures, intussusception, paralytic ileus, intestinal displacement, volvulus and torsion, renosplenic entrapment in horses are all examples of intestinal \_\_\_\_\_.
obstruction
66
Intestinal displacement
Internal herniation vs external herniation
* Internal herniation through epiploic foramen or rent in mesentery
* External herniation through body wall opening such as inguinal ring or umbilicus
67
Volvulus vs torsion
* Vovulus is twisting of intestine on its mesenteric axis
* Torsion is rotation of a tubular organ along its axis
68
Example of roundworm in birds
*Ascaridia* sp.
69
Example of round worms in mammals:
*Ascaris* sp.
70
*Ancylostoma* in dogs and cats and *Uncinaria* in dogs are examples of what kind of worms?
Hookworms
71
*Ancylostoma caninum*, a hookwork, passes in milk to puppies from encysted _____ stage larvae.
third
72
Thorny headed worm - hookworm
scientific name?
*Macrocanthorhynchus hirudinaceus*
73
*Trichuris* sp. are examples of what kind of worms? and cause what kind of colitis?
* Whipworms
* Catarrhal colitis
74
Small strongyles are found in the mucosa of the ______ of the horse.
large colon
75
Muscular hypertrophy of the ileum is seen in what two species?
Pigs and horses
76
*Hemomelasma ilei*
* What species?
* Associated with ?
* Horses
* strongyle migration
77
Colitis X
* Species affected?
* Lesions?
* Possible cause?
* Horses
* Edema, congestion, hemorrhage of mucosa of colon and cecum
* Hemorrhage in adrenal glands
* May be due to clostridial infection
78
Jejunal hemorrhage in cattle is also known as ______ or \_\_\_\_\_
* Hemorrhagic Bowel Syndrome
* Intraluminal-Intramural Hemorrhage of the Small intestine
79
What is the cause of jejunal hemorrhage in cattle?
The cause is unknown - occurs sporadically in dairy cattle
80
Jejunal hemorrhage in cattle causes the formation of ____ in \_\_\_\_.
ropy obstructive clots in duodenom and jejunum
81
Adenomatous polyps
* Benign intestinal neoplasm
* Found in anorectal area of dogs - may protrude from anus - may have bright red blood in stool
* Some may undergo malignant transformation - induration due to desmoplastic reaction
82
Leiomyoma can be a \_\_\_\_(benign/malignatn) intestinal neoplasm.
Benign
83
Neoplasms of the Intestine:
Adenocarcinoma
* Most occur in the ______ of the dog; and _____ of the cat.
* Malignant
* may involve small or large intestine particularly in the dog or cat
* most occur in the colon and rectum of the dog; and the small intestine of the cat
* Infiltrate the gut wall causing fibrosis and stenosis
84
Neoplasms of the Intestine:
Lymphosarcoma
* Malignant
* May be segmental or diffuse and infiltrate all layers of the small and large intestine
* Are seen in many species
* Villous atrophy, malabsorption, and ulceration are common
85
Neoplasms of the intestine:
Gastrointestinal Stromal Tumors (GIST)
* Arise from?
* May cause \_\_\_
* Seen in what two species?
* Location?
* Malignant
* Mesenchymal tumors that are thought to arise from smooth muscle (leiomyosarcomas) or myofibroblasts based on immunohistochemical stains
* May cause bowel obstruction
* Are seen mainly in dogs and horses in the SI and cecum
86
Ruminants
E. coli in neonates, Salmonella sp. infection, traumatic reticuloperitonitis in cattle - all can cause inflammation of the \_\_\_\_\_
peritoneal cavity - peritonitis
87
In pigs, glasser's disease is caused by ______ and causes peritonitis.
*Hemophilus parasuis*
88
How can a coronavirus cause feline infectious peritonitis?
Probably a mutated enteric coronavirus
89
Wet form of feline infectious peritonitis results grossly in what kind of exudate?
proteinaceous exudate in the body cavity
90
The dry form of feline infectious peritonitis results in what kind of inflammation in multiple organs?
What is found on serosal linings?
* Pyogranulomatous
* Translucent plaques
91
Underlying lesion of feline infectious peritonitis that kill the cat?
Pyogranulomatous vasculitis
92
Airsacculitis in turkeys is mistakenly called _____ because of habbit. And it means:
peritonitis; inflammation of the air sacs
93
Pedunculated mesenteric lipoma
* Neoplasm of peritoneal cavity
* Can strangulate small intestine or descinding colon in horses
94
Carcinomatosis
* Neoplasms of the peritoneal cavity
* Plaque-like masses of tumor cells on serosal linings of abdominal area in a chicken
95
Mesothelioma is a neoplasm of the peritoneal cavity. True or False.
True
