Skeletal Muscle Essay

1087 Words 5 Pages
One thing that many living things require is the need for muscles in order to function. Humans are composed of more than half their body weight of muscle (Saunders, 2016). Muscles are the building blocks of an abundant amount of functions. For example, muscles are required in order to help many organisms eat, protect themselves, most movements, etc. The basic unit of muscles is referred to as a sarcomere, and when it contracts it excretes a force. The contraction is the result of the interaction between cross-section bridges. There are three major types of muscles; skeletal, smooth, and cardiac muscle (Saunders , 2016). For the following experiment, skeletal muscle will be utilized and its structure begins with the myofibrils. Multiple myofibrils …show more content…
To be more specific, how size and mass of the muscle affect the force exerted and the super maximal value, how interval time between stimuli affect force, and how summation and tetanus can be resulted if intervals between stimuli are to short. Examining these areas are important because muscles are responsible for a majority of functions that are required for life. For the experiment it was hypothesized that when the voltage being applied to the muscle was increased so will the strength of the contraction, the larger the muscle the larger the force exerted will be, and when the time between stimuli frequencies is decreased it will eventually morph the contraction into one, tetanus. In terms of cross sectional area and stretch, it was expected that as cross section area increased so would the force exerted and the more the muscle is stretched the larger the force exerted will be (Deban & Olberding, …show more content…
Then the muscle was severed at the achilles and above the knee joint. Next the power lab and the force transducer was setup and then calibrated. Recording for 5 seconds, adding 50 grams to the hook, and recording for another 5 seconds did this. The N-value was calculated and entered into the program, concluding the calibration. Next the calf muscle was connected to the force transducer, by placing a hood through the achilles and the knee was clamped. Also an electric probe was put on the muscle. Then the super maximal stimulus was determined, setting the interval time to 1,000ms and the voltage to 50mV did this. Several trials were conducted until three successive peaks appeared. The voltage was increased by intervals of 50mV until the three successive peaks appeared. The voltage where the three peaks appeared was multiplied by 1.5, resulting in the super maximal stimuli. Next the stimuli frequency was tested by setting the voltage to the super maximal stimuli and setting the time to 400ms. It was then repeated 6 more time at 200ms, 100ms, 80ms, 60ms, 40ms, and 20ms. The time that gave the highest tetanic force was noted. Lastly, force and length relationship was tested. The slack was removed from the muscle, voltage was set to the super maximal amplitude, and time was set to the highest tetanic force. Then 20 trials were conducted, increasing the tension by 1mm each time

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