Please use the following background information to answer questions 2-4: Jack, a
ID: 3476193 • Letter: P
Question
Please use the following background information to answer questions 2-4: Jack, a student in BIO 131, is the subject for this lab and has his EMG recorded during a maximal contraction. To achieve a maximal contraction, he must lift 45 pounds. Six months later, after working out steadily and maintaining a healthy diet, Jack's muscles are noticeably bigger. He decides to try to elicit a new maximal contraction (and record the EMG), and is now able to lift 60 pounds. 2. (2 points) Compare the EMG recordings for Jack's maximal contraction "before" and after" his 6-month training sessions. Circle the correct answer a. The EMGs will have the same amplitude. b. The "before" EMG will have a larger amplitude. c.) The "after" EMG will have a larger amplitude. (4 points) After his muscle growth, did Jack need greater or fewer motor units to lift 45 pounds as he did "before"? As a result, would the amplitude of Jack's EMG be larger or smaller compared to the amplitude "before". Please explain your answer. 3. 4. (2 points) Suppose we take samples of Jack's muscle before and after his training period and look at them under a microscope (note: the samples are the same size). After Jack's 6-month training period, you would expect the "after" muscle sample to contain (circle the correct answer below).. the same number of muscle fibers with a reduced amount of thick and thin filaments per fiber. the same number of muscle fibers with an increased amount of thick and thin filaments per fiber. an increased number of muscle fibers with the same amount of thick and thin filaments per fiber. a. b. c.Explanation / Answer
1) After muscle growth did Jack need greater or fewer motor units to lift 45 pounds as he did before?As a result would the amplitude of Jacks EMG be larger or smaller compared to amplitude before?
answer :-Jack will need fewer motor units to lift 45 pounds due to constant exercise his body is accustomed to carry heavy weights. The EMG depends on the strength of the muscle, hence the amplitude will be larger compared to amplitude before as strenth of muscle has increased.
2)would number of musvle fibre increase or decrease or stay the same.
Answer:-c) the same number of muscle fibre with increase of thin and thick filaments per fibre.
because:an increase number of actin and myosin filaments in each muscle fibre which causes enlargement of muscle fibre called as fibre hypertrophy. Hypertrophy occurs to a much greater extent when the muscle is loaded during contractile process.only a few strong contractions each day are required to cause significant hypertrophy within 6 to 10 weeks.