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10 Cards in this Set
- Front
- Back
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what muscles does MG affect first typically?
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eye muscles and eyelid muscles - drooping
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what is a compound action potential
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when you stimulate a motor neuron and record the sum of many action potentials at the muscle
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how does MG change the junctional folds?
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the antibodies make them shallower
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how do the anti-AchR ab's decrease the # of receptors?
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they cross link them and increase their rate of internalization
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what is the structure of AchR?
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2 alpha, beta , gamma, and delta.
5 subunits |
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what is the safety zone
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at a NMJ, stimulation by a motor neuron generate many AP's in the muscle. inb/t motor neuron AP's, ACh is not being released. in a normal person, the synapse level of Ach goes down inb/t motor neuron AP's but it stays above the minimal level needed to stimulate the muscle fiber. This excess Ach is the safety margin
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what is the saftey margin in MG?
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Ach diffuses laterally more (b/c the junctional folds are shallower) this gives it less of a safety margin, and AP's are lost. NMJ is not so hi-fi
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why are anti-AchR antibodies T cell dependent
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the T cell must recognize the primary immunogenic region and release cytokines which cause the B cell to turn into plasma cells producing antibodies.
B and T cells recognize different epitopes on the AchR |
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how do blalock's B and T cell vaccines work?
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take the antibody against AchR and make an idiotype
then immunize the person with the idiotype. the immune system will make an antibody against the immunotype which will also bind to the anti-AchR antibodies. for the T cell, this will cause the T cells responding to the AchR to be destroyed b/c they produce this antibody on their surface. they cant produce cytokines to help the b cells. with the b cells, the immune response will bind the immunoglobin on the b cell surface and will prevent the antibodies from being produced |
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what is the antigen receptor mimic?
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the idiotype - what the pt's are immunized w/
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