MSK and Neuro Path Flashcards
5 causes of muscle atrophy
- neuropathic
- disuse
- malnutrition
- cachexia
- senility
4 histo changes in muscle atrophy
- smaller myofibres
- loss of myofibre
- replacement by fat
- fibrosis
Steps in degeneration of muscle
- swelling
- hypereosinophilia
- loss of striation
- coagulation
- fragment
- tension bands
- mineralization
Which cells make new myofibres
Satellite cells –> myoblasts –> myotube –> differentiate –> myofibre
Least to most susceptible cell type in muscle to ischemia
myofibre > satellite > fibrocyte
Some m. toxins
- monensin
- salinomycin
- doxycyclin overdose in calves
- seasonal pasture myopathy (box elder, maple)
3 Bac that can infect m directly
- Clostridia
- Trueperlla pyogenes
- actinobacillus ligneresi
2 types of bone formation
- endochondral
- intramembranous
2 types of bone and their diff
- lamellar: takes time, trabecular bone
- woven: rapid prod, reactive, periosteal new bone
Stages of joint degeneration
Injury –> degeneration –> fibrillation –> ulceration –> eburnation
5 ways joint capsule can react to injury
- hyperplasia (synovial or villous)
- inflammation
- pannus
- fibrosis (periarticular)
- osteophyte
Define pannus
- covering of articular surface with granulation tissue
Neutrophils in joint fluid in SA vs LA indicates what type of inflammation most likely?
- SA: immune-mediated
- LA: septic
Most common type of skeletal neoplasia in cats
Vx site associated sarcoma
Signs of neoplasia in CSF
- high protein
- normal cell count
4 Histo changes in peripheral NS in nerve injury
- axon swelling
- axon fragmentation
- myeline sheath sheath swelling?
- together = Wallerian degeneration
- may also see digestion chambers = macs degrading tissue
What happens to neuron in neuronopathy? Causes?
- directly target nerve body
- drugs (cisplatin, doxrubricin), B6 toxicosis
What happens to neuron in primary axonopathy? Causes?
- loss of axons, myeline sheath fine
- organophosphate poisoning, laryngeal hemiplagia, diabetes
What happens to neuron in primary demyelination? Causes?
- loss of myelin, axon initially fine but will lose over time if not recovered
- chronic lead toxicity, coonhound paralysis, hypothyroidism, immune mediated
Pathogens that cause malformation of CNS
- BVD
- Classical swine dz
- feline panleuk
- bluetongue
- cache valley
4 routes CNS can be exposed to pathogens
- veins (e.g. face –> pit gland)
- direct penetration (e.g. dehorn)
- nerves
- CSF
Common bac that cause neutrophilic inflamm.
- E. coli
- step
- trueperella (abscess)
- Listeria (via nerve)
- histophilus (via haem)
Histo change in lymphocytic encephalitis
- perivascular cuffs (from lymphocytes)
- gliosis (=clusters of glial cells)
- satellitosis ( = glial cells gathering around necrotic neurons)
- neuronophagia by glial cells
- necrosis
Type of neuro cells most to least susceptible to ischemia
- neurons
- oligodendrocytes
- astrocytes
- microglial
- fibrovascular tissue
Causes of polioencephalomalacia
- thamine deficiency
- sulphur tox
- acute lead tox
- salt tox
- edema dz
3 gross lesions of polioencephalomalacia
- gyri flattened
- tentorial herniation
- coning of cerebellum
What is one predisposition in diet to thiamine responsive polioencephalomalacia
High carbs
Signs of acute vs subacute vs chronic lead tox
- acute: serizure, severe neuro signs
- subacute: diarrhea, depression, blind, head press
- chronic: myelinopathy
