BONE-06 Flashcards
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(Alteraions in myofiber side: Atrophy)
- Reduction in size - reduced fiber diameter of cross sectional area
- Causes? (3 of them)
- see more gross lesions or histological?
- how fast is process?
- different from hypoplasia how?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/946/225/q_image_thumb.jpg?1659445440)
- denervation, disuse, cachexia
- gross
- rapid
- hypoplasia mean incomplete development
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/946/225/a_image_thumb.jpg?1659411734)
(Alteration in myofiber size: Hypertrophy)
- increase in muscle fiber diameter or cross-sectional area by what?
- physiologic hypertrophy considered normal - due to what?
- compensatory hypertrophy is nonspecific and occurs secondary to what two things?
- addition of myofilaments
- exercise conditioning
- decrease number of functional myofibers
or
interference with normal metabolic processes
(pic - monkey has been given anabolic steroid)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/946/996/a_image_thumb.jpg?1659411736)
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(A. Circulatory)
(Downer Syndrome)
- muscle ischemia due to what?
- good condition - what animal most commoly?
- Pressure within muscles exceeds what?
- acute looks how?
chronic?
- external pressure
- cows
- venous and arterial pressure
- muscles dark and hemorrhagic
pale
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/290/a_image_thumb.jpg?1659411736)
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(B. Nurtritional)
- principal deficincies are what?
- resuilt in loss of antioxidant defense
Hi oxygen requirement and high contractile activity make striated muscle sensitive to what?
- Selective, segmental degereneration of what?
what remain intact
- selenium and vitamin E
- oxidative injury
- contractile components
basal lamina and satellite cells
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(Nutritional Myopathy)
- Vitamin E/selenium-containing enzymes are physiologic antagonists to what?
- In absence of protection, cellular membranes modified by what?
altering ability to do what?
- Mitochondrial calcium overload leads to what two things?
- free radicals
- free radicals
maintain ion gradients
- calcium-induced hypercontraction of myofibrils & degeneration of myofibers
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(Nutritional Myopathy)
- occurs in what primarily?
- usually what age?
- Clinical signs may be precipitated by what?
- pigs and herbivores
- _young (_can occur in utero)
(Neonatal animals rely on stores of selenium accumulated during gestation)
- physical activity
(Stiffness, dyspnea (heart failure), shuffling gait, recumbency)
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(Nutritional Myopathy)
(Lesions)
- affected muscle looks like what?
- marked what of muscle?
- Pale, irregularly opaque, yellow to creamy white
- usually what muscles affected?
- what muscles in young?
- uni or bilateral?
- may develop myoglobinuria
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/827/q_image_thumb.jpg?1659445442)
- pale (white muscle disease)
- mineralization
- thigh and shoulder
- tongue and neck
- bilateral
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/827/a_image_thumb.jpg?1659411736)
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(Nutritional Myopathy)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/923/q_image_thumb.jpg?1659445442)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/923/a_image_thumb.jpg?1659411737)
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(Nutritional Myopathy)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/928/q_image_thumb.jpg?1659445442)
(Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(Nutritional Myopathy)
(Pigs)
- Spontaneous disease where intensive pig rearing practiced
- what more common - skeletal lesions or hepatic necrosis (hepatosis dietetica) and mycardial necrosis and hemorrhage (mulberry heart diesease)
- most common when?
- injections of what can cause?
- gross lesions?
- mortality?
- latter
- 6-20 weeks
- iron (catalyst for lipid peroxidation of cell membranes)
- difficult to detect (pale muscles)
- can be high
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/947/931/a_image_thumb.jpg?1659411737)
Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(C. Toxic)
- phytotoxins, chemical toxins, pharmacological toxins
2. may be difficult to distinguish from what?
- segmental or diffuse skeletal muslce or myocardial lesions?
4. Act by destroying vit E or selenium?
inhibited by addition of these nutrients?
- more or less lethal that nutritional deficiencies (persistent or generalized toxic influence)
- unremarkable and nonspecific lesions; less often associated with what?
2. nutritional myopathies
- segmental
- no
no
- generally more
- mineralizeation of tissues
Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(C. Toxic Myopathies)
(Monensin Toxicity)
- what is it?
- used for what in ruminants?
- what in birds and animals?
- very toxic to monogastrics or at high doses for ruminants
- order or toxicity?
- antibiotic fermentation product (Streptomyces cinnamonensis)
- grwoth promotion (added as premix)
- coccidiostat
- Horses>dogs/pigs>sheep/goats>cattle>poultry
Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(C. Toxic Myopathies)
(Monensin Toxicity)
- monensin is an ionophore that does what on molecular level?
- Results in what?
- what may account for the low level of calcification of the muscle fragments?
- distorts membrane transport of sodium and potassium
- calcium overload –> death of skeletal/cardiac muscle
- Early mitochondrial destruction
Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(C. Toxic Myopathies)
(Monensin Toxicity)
(Clinical Signs)
Lethargy
•Stiffness
•Muscular weakness
•Recumbency
•Horses may exhibit colic symptoms
(Postmortem LEsions)
- ill-define pale streaks in myocardium and skeletal muscle
- is minearlization of muscle a feature?
- see what in chronic?
- not a major one
- atrophy of skeletal muscles
![](https://s3.amazonaws.com/brainscape-prod/system/cm/056/948/840/a_image_thumb.jpg?1659411737)
Diseases of Muscle)
(1. Degenerative Diseases of Muscle)
(D. Exertional Myopathies)
- Intensive or exhaustive activity of major muscle masses
- Glycolytic fibers vs. the type 1 oxidative fibers
what gets rapidly/abberantly used?
leading to what?
- coagulation of what?
- diffusion of what?
- water lost to what?
leading to what?
- Myoglobinemia, myoglobinuria, and metabolic acidosis
- glycogen
local heat and lactic acid
- contractile proteins
- lactate and heat
- interstitium
increased pressure/ischemia