BSC 2346 Module 4 Case Study

BSC 2346 Module 4 Case Study • Question 1 1 out of 1 points 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. Jordan’s history aligns most closely with which diagnosis? Selected Answer: Duchenne muscular dystrophy Answers: Multiple sclerosis Myotonic dystrophy Amyotrophic lateral sclerosis • Question 2 Duchenne muscular dystrophy 0.5 out of 1 points 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. Selected Answer: Correct Answer: the muscle would show degeneration in comparison to earlier biopsy Degenerating skeletal muscle fibers. Proliferation of connective tissue around the degenerating muscle cells. Numerous macrophages in the area. Muscle fibers that appear more dense or dark in color. Response Feedback: • Question 3 [None Given] 1 out of 1 points Explain, in your own words, why Jordan’s brother appears to have the same disease and why his sisters are unaffected. Selected Answer: Correct DMD or Duchenne muscular dystrophy is inherited and typically boys affected as girls are typically just carriers. Answer: Duchenne muscular dystrophy (DMD) is a progressive form of muscular dystrophy that occurs primarily in males. Genetic changes causing Duchenne muscular dystrophy (DMD) can be passed down in families. The DMD gene is located on the X chromosome, one of the two types of sex chromosomes. Males have an X and a Y chromosome; whereas females have two X chromosomes. Response Feedback : [None Given] • Question 4 1 out of 1 points Jordan’s calves appear enlarged. Which of the following statements explains this phenomenon? Selected Answer: Answers: As his muscles degenerate, the muscle tissue is replaced by collagen and adipose tissue. As Jordan ages, the neuromuscular junction loses its neurotransmitters. Jordan’s muscle cells are experiencing calcification because the actin and myosin filaments are no longer able to release from each other. As his muscle degenerate, calcium replaces the water in the muscle cells. As his muscles degenerate, the muscle tissue is replaced by collagen and adipose tissue. • Question 5 1 out of 1 points Jordan displayed Gower’s sign at a young age. Which of the following statements explains why this this true? Selected Answer: The weakness of his proximal leg muscles and erector spinae muscles force Jordan to use his arms to push on the floor. Answers: His neuromuscular junctions were interrupting the signals to contract his muscles. The chronic contractures in Jordan’s lower legs cause him to be reliant on his upper body for strength. Jordan’s quadriceps and gluteus maximus are in spasm, which causes him to fall to his knees when trying to stand. The weakness of his proximal leg muscles and erector spinae muscles force Jordan to use his arms to push on the floor. • Question 6 0 out of 1 points Weakness in his erector spinae muscles forces Jordan to assume which exaggerated position when standing? Selected Answer: Scoliosis Answers: Lumbar hyperlordosis Cervical hyperlordosis • Question 7 Scoliosis Thoracic hyperkyphosis 1 out of 1 points 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.) Selected Answer: He will take calcium supplements because if he doesn't bear weight on his legs, his legs will think they don't need to build and maintain the strength and bone density Correct Answer: Calcium provides material to build bone extracellular matrix Response Feedback: [None Given] • Question 8 1 out of 1 points Jordan is prone to respiratory infections, in part because of the weakness of which muscles? Selected Answer: Diaphragm and abdominal wall muscles Answers: Serratus anterior and scalene muscles Pectoralis major and pectoralis minor Diaphragm and abdominal wall muscles • Question 9 Hyoid muscles 1 out of 1 points Genetic testing would reveal that Jordan has a y-linked disorder. Selected Answer: Fals e Answers: True Fals e • Question 10 1 out of 1 points In your own words, briefly describe the role of dystrophin within the motor unit. Selected Answer: Correct Dystropin is a protein that helps build muscle cells- strengthen muscle fibers, and protect from injury when muscles contract and relax. Answer: Mechanical: 1. stabilization of membrane (sarcolemma) during contraction & relaxation 2. link between intracellular cytoskeleton & extracellular matrix Functional: 1. differentiation of muscle fibers 2. organization of postsynaptic membrane and ACh receptors Response Feedback: [None Given] • Question 11 1 out of 1 points 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. Colette has been sore “all over,” but her primary area of concern is the posterior right thigh. Which of the following muscles could be causing the soreness in this region? Selected Answer: Biceps femoris Answers: Biceps femoris Vastus lateralis Rectus femoris • Question 12 Peroneus longus 1 out of 1 points Colette has played softball for over 20 years and has been told in the past that she may have a rotator cuff injury. Which of