BIOL 121 Lecture Notes - Lecture 26: Withdrawal Reflex, Motor Program, Premotor Cortex
Document Summary
Skeletal muscles are broken into functional groups known as motor units. Each motor unit is controlled by a motor neuron. The cell bodies of the motor neurons for a given muscle are clustered in the ventral horn known as the motor neuron pool. Input to the pool equally distributed among all neurons. The neural systems that control body movement are arranged in a motor control hierarchy composed of. Sensorimotor cortex, cerebellum, basal nuclei, brainstem nuclei, thalamus. Distribution of plan to the motor neurons. Spinal cord and brainstem, motor neurons and afferent nerves. Intention to move leads to formation of a motor program. Motor program sent down descending pathways to the local level, where it is integrated with incoming afferent signals and local interneurons to create a pattern of motor neuron excitement. Afferent feedback during movement used to make modifications. Also used to adjust motor program for better future. Most input to motor neuron pool is by interneurons.
