PSYCH261 Chapter Notes - Chapter 8.1 and 8.2: Extrafusal Muscle Fiber, Intrafusal Muscle Fiber, Gamma Motor Neuron

• School: University of Waterloo
• Department: Psychology
• Course: PSYCH261
• Professor: Christopher Lee

Document Summary

Psych 261 textbook chapter 8. 1 and 8. 2 reading summary. Skeletal muscle: one of the striated muscles attached to bones. Flexion: a movement of a limb that tends to bend its joints; the opposite of extension. Extension: a movement of a limb that tends to straighten its joints; the opposite of flexion. Extrafusal muscle fiber: one of the muscle fibers that are responsible for the force exerted by contraction of a skeletal muscle. Alpha motor neuron: a neuron whose axon forms synapses with extrafusal muscle fibers of a skeletal muscle; activation contracts the muscle fibers. Intrafusal muscle fiber: a muscle fiber that functions as a stretch receptor, arranged parallel to the extrafusal muscle fibers, thus detecting changes in muscle length. Gamma motor neuron: a neuron whose axons form synapses with intrafusal muscle fibers. Motor unit: a motor neuron and its associated muscle fibers.