Kinesiology 1080A/B Lecture Notes - Lecture 6: Intrafusal Muscle Fiber, Alpha Motor Neuron, Lower Motor Neuron

• School: Western University
• Department: Kinesiology
• Course: Kinesiology 1080A/B
• Professor: Matthew Heath

Document Summary

Green dot is the cell body of an alpha motor neuron. Thinner, smaller fibre is intrafusal muscle fibre that sends information to the spinal cord via the dorsal root ganglia. Alpha motor neurons cause extrafusal fibres to contract, gamma motor neurons control sensitivity of stretch fibres to. Propriospinal neuron is a neuron existing in the spinal cord allowing neurons to communicate with one another. Can have one that directly synapses between two alpha motor neurons. Pyramidal tract is composed of corticobulgar tract. Cc modulates action of motor neurons in brain stem and spinal cord:corticobulgar tract. At the point of the bulb in the brain stem where the upper motor neurons innervate their lower motor neurons. Circles represent cell body of neuron (descending motor pathway where a single neuron innervates directly with an alpha motor neuron) Upper motor neuron composed of neuron from cortex, cell body and axon, that synapses onto spinal cord (red neuron)