Assignment task:
History: Susan, a 31-year-old mother of two, begins to notice that she is having trouble focusing her vision, especially right before bed. Over the next week, Susan begins to notice that not only is she having trouble focusing, but she is also now beginning to have problems making facial expressions and swallowing. Becoming concerned, Susan makes an appointment with her doctor. Upon arrival, the doctor performs a series of movement tests and draws blood to perform an acetylcholine-receptor-antibody test. When the test comes back positive, the doctor diagnoses Susan with Myasthenia gravis, admits Susan to the hospital for observation, and orders neostigmine drug therapy. Susan is in the hospital for a week recovering, and upon release, asks her doctor if there are any long-term concerns she should watch out for.
1. Describe the muscle contraction process from the arrival of an action potential at the neuromuscular junction to a full muscle contraction.
2. Describe how a muscle contraction ends. What steps are necessary? What happens to the neurotransmitter released?
3. What is myasthenia gravis? What signs or symptoms of the disease did Susan show that lead the doctor to that diagnosis?
4. What causes muscle weakness observed in myasthenia gravis? Be specific about which part of the process of muscle contraction is being affected.
5. Why did the doctor admit Susan to the hospital for observation? How serious can myasthenia gravis be?
6. What is neostigmine, and why is it effective in the treatment of myasthenia gravis?
7. As the doctor, how would you have answered Susan's final question? What is the long-term prognosis for myasthenia gravis? What other treatments could be considered for Susan? Is there a cure?