Travels through the central nervous system (spinal cord)
Sent to motor neurons, which get depolarized by the electrical signal
Motor neurons then release neurotransmitters
Neurotransmitters bind to receptors on the muscle fiber.
Signals the release of calcium
Calcium binds to Actin (long, thin contractile protein)
Actin then binds to Myosin (short, thick contractile protein). ATP is bound to Myosin
The “sliding filament theory” occurs
Myosin pulls Actin filaments toward the center.
ATP hydrolysis occurs and Myosin dissociates from Actin
Source: Hatfield, Phd, F. C., & Davis, Phd, FASCM, P. O. (2004). Muscle Anatomy and Physiology. Fitness: The Complete Guide (pp. 70-121). Santa Barbara, California: International Sports Sciences Association.
