Muscles 1

Question 1

composed of actin and mysoin filaments

Answer 1

myofibrils

Question 2

calcium ion storage

Answer 2

sarcoplasmic reticulum

Question 3

thin undifferentiated cells that have the ability to undergo mitosis – muscle regeneration

Answer 3

satellite cells

Question 4

skeletal muscle response to injury

Answer 4

degeneration

Question 5

pale due to sublethal muscle fiber damage and edema or dark due to extensive myofiber damage

Answer 5

degenerative muscle reponse

Question 6

skeletal muscle necrosis

Answer 6

rhabdomyolysis

Question 7

more pale than normal and mildly to moderately swollen

Answer 7

early necrotic muscle

Question 8

result of replacement of necrotic muscle

Answer 8

smaller and firmer muscle

Question 9

muscle fiber hyper-contraction
muscle fiber swelling
hypereosinophilia

Answer 9

microscopic early necrotic muscle lesions

Question 10

responsible for driving muscle fiber regeneration

Answer 10

satellite cells

Question 11

if basal lamina of a damaged myofiber is left intact…

Answer 11

satellite cells with activate forming myoblasts along the endomysium to regenerate

Question 12

if endomysioum does not survive…

Answer 12

muscle regeneration will be inhibited and muscle will be replaced by fibrous tissue leading to scarring and reduced muscle function

Question 13

ischemic myopathy

Answer 13

compartment syndrome
deep pectoral myopathy of poultry

Question 14

muscle degeneration and necrosis secondary to insufficient blood flow caused by muscle swelling in non-expandable space

Answer 14

compartment syndrome

Question 15

cause of compartment syndrome

Answer 15

tissue swelling within the compartment leads to increased compartmental pressure and increased resistance to flow of blood into space

Question 16

green muscle disease of turkeys and chickens caused by vigorous flapping of wings leading to compartment syndrome in the supracoracoid muscles

Answer 16

deep pectory myopathy in poultry

Question 17

nutritional myopathy in calves

Answer 17

white muscle disease

Question 18

nutritional myopathy in sheep

Answer 18

stiff lamb disease

Question 19

nutritional myopathy in pigs

Answer 19

mulberry heart disease

Question 20

muscle damage secondary to a deficiency of free radical scavengers (vitamin E and selenium)

Answer 20

nutritional myopathy

Question 21

reason for muscle susceptibility to nutritional myopathy

Answer 21

high oxygen requirements and contractile activity of striated cardiac muscle

Question 22

species most susceptible to ionophore toxicity

Answer 22

horses

Question 23

most toxic ionophore

Answer 23

monensin

Question 24

location of ionophore toxicity in horses

Answer 24

myocardial

Question 25

location of ionophore toxicity in sheep and pigs

Answer 25

skeletal muscle

Question 26

location of ionophore toxicity in cattle

Answer 26

skeletal cardiac

Question 27

classic clinical sign of ionophore muscle toxicity

Answer 27

myoglobinuria

Question 28

caused by anthraqinones and their derivatives or various plant glycosides and alkaloids

Answer 28

cassia toxicosis

Question 29

CS of cassia toxicosis

Answer 29

diarrhea muscle weakness reluctance to walk myoglobinuria recumbency

Question 30

massive muscle necrosis in wild and zoo animals can be observed secondary to extreme muscle exertion

Answer 30

capture myopathy

Question 31

pathophys of captive myopathy

Answer 31

stress = muscle exertion to exhaustion and elevated catecholamines hyperthermia and metabolic acidosis

Question 32

types of exertional rhabdomyolysis

Answer 32

sporadic exertional rhabdomyolysis chronic exertional rhabdomyolysis

Question 33

CS of sporadic exertional rhabdomyolysis

Answer 33

azoturia paralytic myoglobinuria monday-morning sickness black water and tying up

Question 34

triggering of sporadic exertional rhabdomyolysis

Answer 34

week of hard work followed by weekend stall rest with high grain feed

Question 35

physical CS signs of sporadic exertional rhabdomyolysis

Answer 35

swollen, edematous affected muscles dark red-brown uring **renal failure, profuse sweating, acidosis, muscle weakness

Question 36

categories of chronic exertional rhabdomyolysis

Answer 36

recurrent exertional rhabdomyolysis polysaccharide storage myopathy (PSSM)

Question 37

breeds affected by RER

Answer 37

thoroughbreds standardbreds

Question 38

trigger of RER

Answer 38

acutely by exercise resulting in sharp spikes in serum myoglobin and creatine kinase excitement

Question 39

cause of PSSM

Answer 39

mutation in glycogen synthase 1 gene

Question 40

process of glycogen synthase 1 gene mutation

Answer 40

enhances synthesis and storage of amylase-resistant glycogen disrupt normal metabolism of the glycogen

Question 41

sequelae of Type 1 PSSM

Answer 41

abnormal accumulation of intracytoplasmic glycogen within Type 2 myofibers

Question 42

abnormal appearing amylase-sensitive or amylase-resistant polysaccharide in muscle biopsies of horses lacking the GYS1 mutation

Answer 42

PSSM type 2

Question 43

CS of chronic exertional rhabdomyolysis

Answer 43

exhibit stiff gait, bilaterally symmetrical muscle atrophy, muscle cramping and pain, shivers and generalized weakness

Question 44

affected animals found dead observed sick are lame, run a fever, have swollen muscle and gas in muscle and subQ tissue

Answer 44

C. chauvoei blackleg

Question 45

cause of death in blackleg

Answer 45

cardiovascular collapse and shock due to exotoxemia

Question 46

seen at necropsy of black leg

Answer 46

hemorrhagic and gas-filled muscles hemorrhagic rhabdomyolysis

Question 47

suppurative myositis in cattle

Answer 47

trueperella

Question 48

suppurative mysositis in horses

Answer 48

streptococcus

Question 49

suppurative myositis in small animals

Answer 49

staph and strep

Question 50

young dog fever/anorexia general body pain gait abnormalities respiratory signs xray shows irregular periosteal proliferations *marked leukocytosis and increased CK

Answer 50

Hepatozoon americanum

Question 51

an inherited progressive myopathies characterized histologically by ongoing muscle fiber necrosis and regeneration

Answer 51

muscular dystrophy

Question 52

pathophys of muscular dystrophy

Answer 52

defects in sarcolemmal-associated proteins such as dystrophin

Question 53

sequelae of defects and/or deficiencies in dystrophin

Answer 53

progressive muscle damage and myofiber necrosis leads to muscle atrophy and fibrosis

Question 54

inherited myotonia

Answer 54

HYPP

Question 55

pathophys of HYPP

Answer 55

defective sodium channel activity increasing myofiber excitability increasing potassium outflow from cells (hyperkalemia)

Question 56

initial signs of HYPP

Answer 56

sweating muscle fasciculations flashing of third eye lid muscle spasm inspiratory difficulty

Question 57

pathophys of myasthenia gravis

Answer 57

autoantibodies bind to acetylcholine receptors causing receptor cross-linking and internalization leading to damage to neuromuscular junctions and severe decreases in number of acetylcholine receptors

Question 58

what has a strong association with myasthenia gravis

Answer 58

thymoma