Leah, a 20-year-old woman, awakens one morning to atingling, numb sensation covering both of her feet. This hashappened to her a number of times throughout the year. In the past,when experiencing this sensation, within a couple of days to a weekthe numbness would subside, and so she is not too concerned. Abouta week later, she notices that the numbness and tingling not onlypersists, but has also spread up to her knees. Again, she ignoresthe abnormal sensation. By the end of a month’s time, the numbnessspreads to the midline of her body. At this point, she becomesalarmed. Leah sees the nurse at her college who tells her that sheshould see a doctor. Leah calls her doctor’s office to schedule anappointment, but the soonest slot is in two weeks. She makes theappointment and goes about her daily routine. The next morning,Leah wakes, but when she attempts to get out of bed, she comescrashing to the floor. Because she is still groggy from sleep, shedoesn’t really understand what has just happened. As she tries tostand up, the muscles of her left leg engage, but as she alsoattempts pushing up with her right leg, she again falls to thefloor. She sits in bewilderment as she tries to make sense of whathas just happened and realizes that she has seriously scraped herknee in her fall. She does not feel the pain from herwound.

Leah thinks about how odd this year has been. Sheremembers another medical issue she had earlier in the year whenshe had lost hearing in her right ear and wonders if there is aconnection to her current condition. At that time, Leah underwentextensive testing, but the ear, nose, and throat specialistremained baffled. He thought that a severe inner ear infectioncould have destroyed her ability to hear on that side, but therewas no conclusive evidence to support this. In an attempt torecover any hearing, he could, the doctor prescribed very highdosages of steroids; he told Leah that she probably wouldn’t see achange, but there were rare occurrences where steroids helped. Toboth Leah and her doctor’s surprise, after about a week ofsteroids, she completely regained hearing in her right ear. It wasa “miracle.” Leah wonders whether she can count on a new miracle toheal her current medical issues.

1. What movements are involved in the action of standingup? What major muscles need to contract to perform theseactions?

Example: Movements and muscles involved in scratchingyour nose: Elbow flexion - Biceps Brachii, Shoulder flexion, -Deltoid

2. Are Leah’s medical problems related to her sensoryneurons, motor neurons, or both? What in Leah’s medical historysupports your answer?