The skeletal muscle is a fixed muscle attached to bones and skin and it is responsible for all voluntary and involuntary movements. The skeletal muscles are controlled by the somatic nervous system (Vander, 288). The gastrocnemius is a whole skeletal muscle, comprised of many single muscle fibers. “The gastrocnemius muscle is one of the frog’s extensor muscles and it aids the frog in its jumping movement” (Meisami, 100). It is possible to do the same experiment on a single muscle fiber, as well as the whole muscle fiber.

The second part of this experiment was a direct stimulation of the human forearm muscle and induction of finger movements. Once again, this involved stimulation of the muscle with a direct electrical current. We placed the electrical stimulator on the flexor digitorum sperficialis muscle of the forearm. When we did this experiment we found the minimal electrical stimulus required to achieve a movement and contraction of the FDS. During this experiment there was a time from when the electrical charge starts to move through the sarcolemma to the time when the muscle contraction begins. The brief period of time we learned is called the latent period. We also found that there is a greater latent period in the human than the frog. In this experiment we used a stimulator, which is the same device as earlier stated. The McADDAM is part of the computer, which moves the signals from the Physiogrip trigger to electronic signal. With these electronic signals, the computer is able to recognize what is happening with the muscle movement. The Physiogrip Transducer is shaped like a pistol trigger and the twitching finger will be placed on and the transducer will help display the mechanical force to an electrical signal for the Macintosh computer to read. Therefore, in both labs we were able to determine an intensity-tension relationship, length-tension relationship, and frequency-tension relationship.

As the frequency was increased, the muscle went through summation. The twitches added together until they reached their maximum, and tetanus was achieved. This is because the calcium ions did not have time to go back into the Sarcoplasmic Reticulum and restart the entire process. The sarcomeres are the smallest unit of muscle cell that are separated by elastic fibers called z-lines. We can find within each sarcomere two typed of myofilaments. These myofilaments are positioned along the sarcomere’s length. Thick myofilaments are made up of myosin, and thin myofilaments are made up of actin molecules. A sliding movement of the thin filaments with the thick filaments causes contraction. This results in the shortening of the sarcomere.

Some topics in this essay:
Physiogrip Transducer, Sarcoplasmic Reticulum, Laboratory Manuel, , Macintosh Computer, Function Lab, Finally MacLab/4-Chart, muscle fatigue, muscle contraction, gastrocnemius muscle, skeletal muscle, action potential, force transducer, frog’s gastrocnemius, muscle function lab, nervous system, graded potential, frog’s gastrocnemius muscle, muscle tension, relationship length tension, increasing frequency stimulation, single muscle fiber,