PSYC 427 Lecture Notes - Lecture 3: Postcentral Gyrus, Alpha Motor Neuron, Primary Motor Cortex
Document Summary
Descending brainstem pathways contribute to type of gait. Locomotor example with totally spinal cord cat. Remarkable capacity for coordinated locomotion that change in an adaptive way with sensory input that resonates in spinal cord and brainstem only. Connections between cortex and spinal cord in terms of outflow - how cortex influences state of spinal cord. Central sulcus divides motor cortex from somatosensory cortex. Can see where outputs go in spinal cord, and can influence different things. Output from primary motor cortex terminates in a variety of places in spinal cord. Terminates in ventral horn (lateral part and medial part) and connect monosynaptically to alpha motor neurons (large diameter, have efferent fibers that connect to peripheral muscles to produce contraction). Majority of connections in primary motor cortex go to intermediate zone - interneurons (reflexes, and project onto motor neurons, produce elaborate behaviours) Outputs from premotor cortex cross at pyramid so innervate contralateral muscles (3/4 of neurons cross here)
