PSYC 106 Chapter Notes - Chapter 8: Reticular Formation, Motor Planning, Vestibulospinal Tract
Document Summary
Can perform 2 classes of movement: flexion- movement that bends joints; opposite of extension, extension- movement that straightens joints; opposite of flexion, *muscles contract, limbs flex. Contains 2 types of muscle fibers: extrafusal- responsible for force exerted by contraction of skeletal muscle form synapses with alpha motor neurons. 1 axon serves multiple muscle fibers (number depends on the amount of control that we have of that muscle. Muscle contraction is not an all or none response: strength of contraction depends on the average rate of firing of motor units. Brain"s control of movement primary motor cortex- arranged as a map (homunculus), where each point corresponds to a muscle in body: called somatotopic organization, stimulation of these areas causes muscle movement in that body part. Connections between motor and sensory areas that correspond to same body part. Allows for rapid feedback to the motor system during manipulation of objects.
