Pathophysiology Flashcards
What induces the primary peristaltic wave?
Caudal pharyngeal muscle contraction
What cranial nerve is associated with muscles of mastication?
CN V - the trigeminal
What cranial nerves are involved in swallowing?
V, VII, IX, X, XII
How does the esophagus differ between dogs and cats/horses?
Dogs- skeletal muscle diffusely Cats/horses - the caudal 1/3 is smooth muscle (myenteric plexus); the cranial 2/3 is striated muscle (PNS/vagus nerve)
Normal gastric peristalsis rate?
3 waves/min
Gastric emptying of LIQUIDS
non-caloric = monoexponential caloric = slower linear rate depending on volume expansion
What are the three phases of solid food emptying? Give a short description of each.
- Initial lag phase - little to no food empties; food ground to 1-2 mm particles 2. Prolonged steady state phase - constant emptying rate determined by caloric density 3. Dogs - Digestive migrating motility complex - late slow phase that occurs when the stomach is nearly empty 3. Cats - Digestive migrative spike complex
What is the difference between the canine digestive motility complex and the feline digestive migrating spike complex?
DMSC - higher propagation speed, shorter contraction duration and greater force of contraction when compared to DMMC in dogs
What are the 3 phases of the digestive migrating motility complex?
Phase 1: quiescent Phase 2: activity Phase 3: intense contractions - sweeping peristaltic waves every 4-5 min; during fasting state occurs every 110 min or so
What are the functions of cholecystokinin? (4)
- gall bladder contraction - stimulates pancreatic exocrine secretion - Relaxation of sphincter of Oddi - Delays gastric emptying (counteracts gastrin)
What is the function of secretin? (2)
- secretion of bicarbonate from the pancreatic ductal cells in response to acid in the SI - slightly delays gastric emptying
What are the functions of gastrin?
- stimulates gastric acid secretion by parietal cells - pancreatic enzyme secretion - gastric motor function and the pyloric pump
What are the normal GI transit times (according to O’Brien and Miyabayashi)?
- Gastric transit: 15-25 minutes to duodenum - Complete gastric empty: 76 min - SI transit: 90-120 minutes to reach the ICJ - SI emptying: 3-5 hours (completely in colon)
Where do epulides arise from?
the periodontal ligament
Where do odontogenic tumors arise from?
Dental lamina
In order, what are the common oral malignancies in cats and dogs?
Dogs: melanoma, SCC, FSA Cats: SCC, FSA
What causes gastric mucosal mineralization in uremia?
metastatic calcification, local acidosis, ischemia, hyperparathyroidism
What would indicate delayed gastric emptying?
- retained liquid barium in stomach >4 hours - some liquid barium present in stomach >12 hours - large amount of barium meal retained >8-10h
In the presence of a GDV, what is the specificity of gastric pneumatosis for gastric necrosis.
high specificity at 93% (pneumoperitoneum 90%)
Where is intestinal adenocarcinoma most commonly found?
dogs - duodenum cats - jejunum and ileum
What bloodwork changes can you see with PLE?
hypoalbuminemia, hypoglobulinemia, hypocholesterolemia and lymphopenia
what paraneoplastic syndromes can be induced by leiomyomas/leiomyosarcomas?
hypoglycemia and nephrogenic diabetes insipidus
In the instance of colonic torsion, what vessels may be involved/occluded?
caudal mesenteric, left colic and occasionally the cranial mesenteric artery (would lead to global mesenteric ischemia)
What are the common feline colonic neoplasms (in order)?
adenocarcinoma, LSA, MCT
How do canine and feline pancreatic ducts differ?
- Cats have one major pancreatic duct that empties with the common bile duct at the major duodenal papilla - Few cats (20%) have a second accessory pancreatic duct that drains via the minor duodenal papilla - Dogs have two pancreatic ducts
What are the functions of alpha, beta and delta pancreatic cells?
- alpha: glucagon - beta: insulin - delta: somatostatin
What breed is predisposed to pancreatic adenocarcinoma?
Airedale Terriers
Ultrasound detection of insulinomas?
56% will show a nodule; 20% show mets
In EHBO, how long does it take for the gall bladder, cystic duct, CBD and IHBDs to dilate?
- GB and cystic duct = 1 day - CBD = 1-2 days - IHBDS = 5-7 days, indicates chronicity
A gall bladder volume of ___ mL suggests obstruction.
10mL, however distension of the GB only occurs in about 50% of cases
What is the determinate of EHBO in dogs?
Dilation of the intra- and extrahepatic biliary ducts. GB dilation is not specific or necessarily indicative of obstruction.
A GB wall thickness of greater than __ mm is suggestive of cholecystitis
> 1 mm
What is the core vs penumbra?
The core is where severe ischemia is present and resulting neuronal death occurs. Penumbra - there is less severe ischemia surrounding the core; neurons are still viable but in danger of neuronal death
Ischemia effects on neuronal elements - in descending order (most affected to least)
neurons>oligodendrocytes>astrocytes>mesidermal microglia>fibrovascular elements
What is the most common territorial infarction site?
cerebellum (rostral cerebellar artery)
Which hemoglobin stages are diamagnetic (have paired electrons)?
Oxyhemoglobin and hemochromes (ferritin, hemosiderin)
What are the paramagnetic stages of hemoglobin (unpaired electrons)?
Deoxyhemoglobin (4 unpaired e), methemoglobin (5 unpaired e)
Which paramagnetic hemoglobin has T1 shortening and why?
Methemoglobin - has 5 unpaired electrons; configuration allows hydrogen to be near the heme, creating T1 shortening
What are the HU of acute and subacute intracerebral hemorrhage/hematoma?
Acute = 55-95 HU Subacute = 40-60 HU
How do you calculate jection fraction?
SV/EDV
How do you calculate % fractional shortening?
(LVIDd- LVIDs)/ LVIDd
