Special pathology - gastrointestinal Flashcards
bright fresh blood in feces is termed
hematochezia
dark blood in feces is termed
melena
neurogastroenterology is
the field of study of the Enteric nervous system
name the two ganglia of the enteric nervous system and what type of innervtion belongs to each
myenteric ganglia (motoric innervation)
submucosal ganglia (motoric and secretory innervation)
layers of the GI Mucosa
– Mucous epithelium
– Lamina propria
– Muscular layer of mucosa
layers of the GI smooth musculature
– Outer longitudinal
– Middle circular
– Inner oblique
2 types of passive absorption
Diffusion
Osmosis (water, chloride, vitamiin C)
NB concentration gradients
Tenesmus
frequent urge to go to the bathroom without being able to go, unproductive straining to go
what is the clinical technique called ballottement
Ballottement is the technique used to evaluate a flowing or movable structure. The nurse gently bounces the structure by applying pressure against it and then waits to feel it rebound. This technique may be used, for example, to check the position of an organ or a fetus.
used to evaluate density and size of abdominal organs by their movement away from and back to the abdominal wall
name 3 clinical techniques used on teh abdomen of a GI suspect patient
2) observing the contour of the abdomen for distention or contraction
2) palpation through the abdominal wall or per rectum
3) abdominal percussion to detect “pings,” -gas-filled
TLI/PLI
Trypsin-like immunoreactivity for diagnosis of pancreatic exocrine insufficiency
Pancreatic Lipase Immunoreactivity has been shown to be sensitive and specific for pancreatitis and have the advantage of remaining increased after the TLI has returned to normal.
how does B12 relate to GI diseases?
B12 or cobalamin deficiency may cause diarrhea, nausea, constipation, bloating, gas, and other gastrointestinal symptoms
A complex interaction occurs between folic acid, vitamin B12, and iron.
B12 is required as a cofactor by gut microbes for various biological processes.
how does folate relate to GI diseases?
folate/folic acid or vitamin B9 deficiency can cause a range of gastrointestinal problems, including diarrhea, stomach pain, and indigestion.
A complex interaction occurs between folic acid, vitamin B12, and iron.
In addition, it helps to increase appetite when needed and stimulates the formation of digestive acids.
Granulomatous Enteritis
is a form of inflammatory bowel disease that affects predominantly the small intestine in horses.
Clinical parasitism depends on
the number and pathogenicity of the parasites, which depend on the biotic potential of the parasites.
Johne’s Disease
is a contagious, chronic, and usually fatal infection that affects primarily the small intestine of ruminants.
Johne’s disease is caused by Mycobacterium avium subspecies paratuberculosis.
name 4 types of Noninfectious diseases of the GI tract
*dietary overload or indigestible feeds
*chemical or physical agents
*obstruction of the stomach and intestines
*congenital defects
Ptyalism
Ptyalism is a condition where you make too much saliva.
a reflex that occurs as a protective
reaction of the body in response to irritation of the mucous membranes
excessive salivation
name 3 types of receptors of the emetic center
serotonergic
adrenergic receptors
+ neurokinergic receptors
are located in the adjacent nucleus tractus solitarii- stimulate the emetic center
name the 2 ways of activating the emetic center
- indirectly by humoral pathways via the chemoreceptor trigger zone
- directly through neural pathways from the GI tract, cerebral cortex, or vestibular system
the chemoreceptor trigger zone is located in
the area postrema in the floor of the fourth ventricle
lacks a blood-brain barrier!
endogenous substances that can stimulate the chemoreceptor trigger zone for emesis can be (2)
uremic or hepatoencephalopathic toxins
exogenous substances that can stimulate the chemoreceptor trigger zone for emesis can be (2)
drugs, toxins
Abdominal pain is induced by stimulation of
visceral nociceptors
Activation of nociceptors requires previous sensitization by pathological events:
inflammation
ischemia
acidosis
dolor coli
Colic
a number of disease conditions that are associated with clinical signs of
abdominal pain
Colica bilaris seu hepatica
biliary colic
Colica pancreatica
pancreatic colic
Colica renalis renal
colic caused by kidney stones
colic can be divided into 3 types:
- Symptomatic colic
Infectious diseases, invasive surgery, and gynecological conditions that cause pain. - Pseudocolic (pain)
Associated with the pain in the liver, kidneys, lungs, pleura, etc. - True colic
Typically occur with gastrointestinal disorders. Most common in horses.
Some Causes of true colic: (6)
Dental diseases and masticatory muscle disorders
Inflammation
Ulceration
Tumors
proliferation of intestinal parasites
Ileus
4 feed related causes of true colic
Inadequate feeding and keeping conditions:
overfeeding
heavy physical load after feeding
spoiled and contaminated (e.g. soil) feeds
harmful inedible impurities (toxins, mechanical irritation)
Ileal impaction is
a condition in which the terminal end of the small intestine becomes blocked by a bolus of feed, resulting in progressive distension of the small intestine and onset of colic.
Ascarid impaction is
usually occurs after worming a young horse that has a large parasite load. Huge numbers of these large parasites die en masse, drift downstream and obstruct the intestine, causing signs of colic.
intestinal Volvulus is
A small intestinal (SI) volvulus occurs in the horse when the intestine rotates on its mesenteric axis through an angle greater than 180o, resulting in strangulation.
Ileus
Loss of motility in the intestines
Functional obstruction of abnormal gastrointestinal (GI) transit
(Postoperative ileus/ paralytic ileus)
2 types of Obstipation
- Spastic obstipation
- Atonic obstipation
- Spastic obstipation is
associated with slowed transit of chyme due to circular muscular contraction in the colon
- Atonic obstipation
associated with the reduced muscle tone of the colon and stoppage of peristalsis.
diarrhea causing Pathogens can be divided into 3
- induce intestinal secretion enterotoxic or enterotoxigenic (E. coli)
- induce inflammation (Lawsonia intracellularis)
- those that are invasive (Salmonella)
- Noninflammatory diarrheas are produced by organisms that
disrupt the absorptive or secretory mechanisms of the enterocytes without destroying the cells
Usually, affect the more proximal portions of the bowel
e.g. enterotoxic E. coli
Rotavirus
Cryptosporidium parvum
- Inflammatory diarrheas are produced by organisms that
produce cytotoxins or are invasive and activate cytokines that initiate inflammatory cascades
The inflammatory diarrheas generally affect the ileum, cecum, or colon.
e.g. Salmonella
Brachyspira
Lawsonia
Combinations of what mechanisms are present in most enteric diseases
Combinations of (noninflammatory+inflammatory) are present in most
enteric diseases
diarrhea classification based on mechanism/character
Osmotic diarrhea
Secretory diarrhea
Exudative diarrhea
Malabsorption Leads to
osmotic diarrhea
which is usually a problem of the small intestine but can cause secondary colonic malfunction
causes of osmotic diarrhea
osmotic diarrhea
cause:
loss of digestive enzmes secondary to microvillus
disruption
crypt or villus enterocyte death
space-occupying lesions of the lamina propria
Osmotic diarrhea involves an
unabsorbed osmotically active substance that draws water from the plasma into the intestinal lumen along osmotic gradients.
nutrients are maldigested or malabsorbed, remain within the intestinal lumen- osmotically attract water
Maldigestion caused by
Exocrine pancreatic insufficiency
Maldigestion mechanics
Retention of nutrients – alterations in intestinal microflora and fermentation of
carbohydrates
further increasing numbers of osmotically active particle in lumen
exerting an osmotic gradient across intestinal mucosa
= osmotic diarrhea
Secretory Diarrhea is
caused by abnormal ion transport in intestinal epithelial cells
e.g.
endogenous enteric hormones or neuropeptides
inflammatory cell products
bacterial enterotoxins
laxatives