Kinesiology 1080A/B Lecture Notes - Lecture 12: Corticobulbar Tract, Upper Motor Neuron, Alpha Motor Neuron
Document Summary
Cc modulates action of motor action of motor neurons in rain stem and spinal cord: corticobulbar tract: motor neuron activity organized by cerebral cortex (cc) Corticobulbar fibres extend from the motor cortex to the bulb (i. e. , the brain stem) Control facial musculature and muscles of mastication. Upper and lower motor neurons: diagram: red line is axons connecting bilaterally within the cns very dependent on what muscles are going to be activated and innervated. Red line is an upper motor neuron (any neuron that originates in the cortex) these synapse with an alpha motor neuron (green) or lower motor neuron. Type of impairment someone has will be different based on their upper or lower motor neuron. Majority of fibres (60-70%) associated with pt are found in frontal motor areas. The other percent of fibres are found in the somatosensory areas (parietal lobe) Ten percent of the million fibres are fast (have very large diameters) important for human movement (quick reaction)