Lecture 27 - Diseases of Motor Units

Question 1

diversity of symptoms in movement disorders?

Answer 1

paralysis, paresis, abnormalities of muscle tone, ataxia (incoordination), involuntary movements (tremor and dyskinesia)

Question 2

Focal/diffuse and acute/chronic combos?

Answer 2

FA: Trauma or vascular, FC: brain tumour, DA: toxin or infection, DC: neuro-degeneration

Question 3

Location of motoneurons?

Answer 3

motor nuclei of the spinal cord, motor nuclei of the brainstem

Question 4

Alpha motoneurons?

Answer 4

innervate extrafusal muscle fibres, responsible for force generation

Question 5

Gamma motoneurons?

Answer 5

control excitability of strech receptors, innervate intrafusal muscles

Question 6

Myotonic muscular dystrophy?

Answer 6

a type of myopathy, myotonia, slowness of relaxation, heart problems, wasting, inherited (dominant), triple CTG on ch19 for myotonin

Question 7

Myasthenia gravis?

Answer 7

autoimmune. fewer ACh binding sites, smalle A of EPPs, reduced safety factor fro transmission reduced, junctional folds shrink

Question 8

Diagnosis of Myasthenia Gravis?

Answer 8

edrophonium - AChE blocker, restored facial movement

Question 9

Botulism?

Answer 9

impairs ACh release at all cholinergic synapses, weakness of striated and smooth muscles (somatic and autonomic)

Question 10

Axotomy?

Answer 10

changes in distal segment (Wallerian degeneration leading to loss in transmission), canges in proximal segment (chromatolysis)