Shrader & Joiner

Question 1

Concerning myocardial necrosis:

1) why is heart muscle at greater risk
2) which spp. are more susceptible

Answer 1

1) bc of its continuous activity

2) herbivores are more susceptible than carnivores

Question 2

What are the sequence of changes seen with myocardial necrosis

Answer 2

1) coagulative necrosis (12-24hrs after insult)
2) leukocytes infiltrate by days 1-3
3) by days 10-20, healing begins (fibroblasts proliferate)
4) fibrosis begins after 6-12 weeks

Question 3

How does myocardial infarction differ between dogs and cats?

Answer 3

in dogs, there’s almost always infarction of the left ventricle & other portions of the heart

in cats, infarctions are in ALL parts of the myocardium

Question 4

Describe the pathogenesis of Japanese ewe

Answer 4

Yew spp. contain toxic alkaloids (Taxine A & B)

they inhibit Na/Ca exchange across myocytes

Question 5

primary cause associated with endocarditis?

How does it differ from endocardiosis?

Answer 5

bacteria

endocardiosis–nodules are limited to the free margins of the valves and aren’t mottled-red in color

Question 6

Which cat breeds are predisposed to HCM and why?

Answer 6

Maine coons and ragdolls

they have a mutation in myosin binding protein C

Question 7

FIP replicates where and causes what type of hypersensitivity?

Answer 7

in macrophages

Type III–immune complexes cause vasculitis

Question 8

Describe the inheritance of duchenne muscular dystrophy (DMD); which gene is mutated?

Answer 8

x-linked recessive

mutation in dystrophin gene

Question 9

6 important roles of dystrophin

Answer 9

myocyte protection
cell motility & division
myocyte contractility
vesicle and organelle movement
cell signaling
maintains cell junctions and shape

Question 10

2 most used models for DMD research?

Answer 10

1) DMD mutant mice (don’t express dystrophin)

2) golden retriever (point mutation creates a nonsense mutation)