For this lab experiment we used electrical stimulation to measure the force-frequency relationship of the quadriceps femoris muscle groups. Doing this allowed us to see how motor unit recruitment and motor unit frequency increased and decreased at varying forces.
Muscle contraction occurs when an electrical impulse is sent from the neuromuscular junction. This impulse causes a depolarization of the muscle membrane. The sarcoplasmic reticulum then begins to release calcium ions which bind to troponin in the muscle. This subsequently causes the tropomyosin to slide along the actin filament causing the muscle to contract. (Squire, 2010)
Excitation-contraction coupling occurs in the plasma membrane and is the sequence of events that allows action
Muscle contraction occurs when an electrical impulse is sent from the neuromuscular junction. This impulse causes a depolarization of the muscle membrane. The sarcoplasmic reticulum then begins to release calcium ions which bind to troponin in the muscle. This subsequently causes the tropomyosin to slide along the actin filament causing the muscle to contract. (Squire, 2010)
Excitation-contraction coupling occurs in the plasma membrane and is the sequence of events that allows action