Skeletal Muscle Lab Report

Movements propagated by skeletal muscle both simple and complex also require interaction with nerve. The nerves and muscle work together to help us do out conscious task with ease. The purpose of this lab is to identify how changes in such variables will affect the properties of the muscle in a human flexor digitorium superficialis (FDS) and to extrapolate the nerve changes from a sciatic nerve of a frog. Neurons are excitable cells structural features such as dendrites, cell body and axon. Excitable cells generate electrochemical impulses also known as an Action Potentials (AP), which propagate down an axon to transmit a signal to another cell. The signal may be transmitted to another neuron through a synapse of another dendrite or will form a Neuromuscular junction with a skeletal muscle cell. Skeletal muscle consists of many multinucleated muscle fibers connected to intercalation of sarcoplasmic …show more content…
However, this requires a cell to maintain a negative electrical potential also known as the resting membrane potential (RMP). This is achieved due to the semi permeable nature of the plasma membrane and multiple V-gated ion channels that are found on it. In a nerve cell, when a dendrite receives a signal, a depolarization event occurs which causes the electrical potential to drop. If it reaches a threshold of (-55 mV) the fast V-gated Sodium channels activate at the axon hillock. This brings the membrane potential to +30 mV in a quick burst as the Na+ ions escape and the sodium channels inactivate. At this point the relatively slower V-gated K+ channels activate and the movement of K+ bring the membrane potential to -90 mV thus hyperpolarizing it. The V-gated K+ channel eventually closes and the membrane potential is brought to RMP (-70 mV) by the Cl- channels. The depolarization then travels through the nerve until it reaches another dendrite synapse or a Neuromuscular Junction