Description
Goals
understanding the role of myelin sheath in function and health of a neuron
Instructions
Part I – Rise and Shine
Kathy, a 20-year-old woman, awakens one morning to a tingling, numb sensation covering both of her feet. This has happened to her a number of times throughout the year. In the past, when experiencing this sensation, within a couple of days to a week the numbness would subside, and so she is not too concerned. About a week later, she notices that the numbness and tingling not only persists, but has also spread up to her knees. Again, she ignores the abnormal sensation. By the end of a month’s time, the numbness spreads to the midline of her body. At this point, she becomes alarmed.
Kathy sees the nurse at her college who tells her that she should see a doctor. Kathy calls her doctor’s office to schedule an appointment, but the soonest slot is in two weeks. She makes the appointment and goes about her daily routine.
The next morning, Kathy wakes, but when she attempts to get out of bed, she comes crashing to the floor. Because she is still groggy from sleep, she doesn’t really understand what has just happened. As she tries to stand up, the muscles of her left leg engage, but as she also attempts pushing up with her right leg, she again falls to the floor. She sits in bewilderment as she tries to make sense of what has just happened and realizes that she has seriously scraped her knee in her fall.
She does not feel the pain from her wound. Kathy thinks about how odd this year has been. She remembers another medical issue she had earlier in the year when she had lost hearing in her right ear and wonders if there is a connection to her current condition. At that time, Kathy underwent extensive testing, but the ear, nose, and throat specialist remained baffled. He thought that a severe inner ear infection could have destroyed her ability to hear on that side, but there was no conclusive evidence to support this. In an attempt to recover any hearing he could, the doctor prescribed very high dosages of steroids; he told Kathy that she probably wouldn’t see a change, but there were rare occurrences where steroids helped. To both Kathy and her doctor’s surprise, after about a week of steroids, she completely regained hearing in her right ear. It was a “miracle.”
Kathy wonders whether she can count on a new miracle to heal her current medical issues.
Questions:
What components of the nervous system are involved in physical sensation? How does sensory impulse move throughout the body?
What components of the nervous system are involved in skeletal muscle movement? How does motor impulse move throughout the body?
What movements are involved in the action of standing up? What muscles need to contract to perform these actions?
Are Kathy’s medical problems related to her sensory neurons, motor neurons, or both? What in Kathy’s medical history supports your answer?
