Science Homework Help

Jordan is now 19-years old. As an infant, Jordan reached many gross motor skill milestones, such as holding his head up, rolling over, sitting, and standing, at normal times. However, he was considered a “late walker” because he took his first steps at 17 months. By 2 years old, his parents noticed a hyperlordotic posture while he was standing. A Gower’s sign and Trendelenberg gait were noted by age four. Throughout his childhood, he suffered progressive muscle weakness, especially in the proximal musculature of the arms, pelvis, and legs. He required orthotic braces to assist his walking and was confined to wheelchair ambulation by age 13.

At 16, he was hospitalized with bronchitis requiring antibiotic treatment, but recovered. Jordan has a history of progressive muscle weakness, but no history of muscle pain or spasm, chest pain, or irregular heartbeat. The only medications that he normally takes are calcium and fluoride supplements. Jordan has three siblings. His older and younger sisters have never had any major medical issues. Jordan’s older brother is also to a wheelchair with problems similar to Jordan’s. No other immediate or distant family members have musculoskeletal issues.

1. Jordan had a biopsy of the left gastrocnemius muscle when he was 5 years old. Based on your answer for his diagnosis, describe the microscopic pathological changes that the pathologist would have noted in her report.

2. Explain, in your own words, why Jordan’s brother appears to have the same disease and why his sisters are unaffected.

3. In your own words, please explain why Jordan must take calcium supplements for the rest of his life. (Hint: Think about your prior material and Wolff’s law.)

4. In your own words, briefly describe the role of dystrophin within the motor unit

Colette has been experiencing some muscle pain and soreness after workouts this last week. She decides to research how muscles work because she wants to find ways to help alleviate her pain. She is hoping to find out the names of the muscles that are aching and find ways to stretch and strengthen them. Answer the following questions to help her find the answers she is looking for.

1. Colette is having trouble understanding the role of fascia within the musculoskeletal system. Explain, in your own words, how fascia is related to the muscles of the human body.

2. In your own words, describe how acetylcholine, calcium, and ATP are involved in the process of muscle contraction.