Brain Control of Voluntary Movements1. Descending pathways from multiple brain regions (Upper motor neurons) influence activity of lower motor neurons2. Hierarchy of controls (organization of cortex)Highest level: Strategy (Association Cortical Areas and Basal Ganglia)Middle level:Tactics (Motor cortex and Cerebellum)Lowest level: Execution (Brainstem and Spinal cord)Sensorimotor systemSensory information used by all levels of the motor system (Hapsis, Pain, and Proprioception)Major Descending Motor Pathways1. Axons from brain descend along two major pathwaysLateral Pathways (Tracts): arms, hands, feet controlVentromedial Pathways (Tracts): posture, reflexesLateral Pathways1. Voluntary movement - originates in cortex;Mostly arms/hands movement control;Corticospinal tract (pyramidal tract) and Rubrospinal tract:Cross at medullary-spinal junction;Run in lateral dorsal spinal columnVentromedial Pathways1. Posture, reflexes, and locomotion: originates in brainstemVestibulospinal tract: head/upper body balance, head turningTectospinal tract: orienting responseVentromedial Pathways1. The Pontine and Medullary Recticulospinal tractsPontine: enhances antigravity reflexesMedullary: inhibits axial extensor musclesSensorimotor Cortical RegionsArea 4 = Primary motor cortex (M1, precentral gyrus)Area 6 = Premotor cortexLateral region  Premotor area (PMA)Medial region  Supplementary motor area (SMA);Motor maps present in all regions: PMA –sensory-guided movements; SMA – internally-guided movementsPrimary Motor Cortex Organization1. Somatotopic organization of precentral gyrus (like postcentral gyrus);2. Contralateral representationPlanning of Voluntary MovementsThe Contributions of Posterior Parietal and Prefrontal Cortex:Represent highest levels of motor controlDecisions made about actions and their outcomeArea 5: Inputs from areas 3, 1, and 2Area 7: Inputs from higher-order visual cortical areas such as MTNRSC 2200 1st Edition Lecture 21Brain Control of Voluntary Movements1. Descending pathways from multiple brain regions (Upper motor neurons) influence activity of lower motor neurons2. Hierarchy of controls (organization of cortex)– Highest level: Strategy (Association Cortical Areas and Basal Ganglia)– Middle level:Tactics (Motor cortex and Cerebellum)– Lowest level: Execution (Brainstem and Spinal cord)• Sensorimotor system– Sensory information used by all levels of the motor system (Hapsis, Pain, and Proprioception)Major Descending Motor Pathways1. Axons from brain descend along two major pathways – Lateral Pathways (Tracts): arms, hands, feet control– Ventromedial Pathways (Tracts): posture, reflexesLateral Pathways1. Voluntary movement - originates in cortex;– Mostly arms/hands movement control;– Corticospinal tract (pyramidal tract) and Rubrospinal tract:• Cross at medullary-spinal junction;• Run in lateral dorsal spinal columnVentromedial Pathways1. Posture, reflexes, and locomotion: originates in brainstem• Vestibulospinal tract: head/upper body balance, head turningThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.• Tectospinal tract: orienting responseVentromedial Pathways1. The Pontine and Medullary Recticulospinal tracts• Pontine: enhances antigravity reflexes• Medullary: inhibits axial extensor musclesSensorimotor Cortical RegionsArea 4 = Primary motor cortex (M1, precentral gyrus)Area 6 = Premotor cortexLateral region  Premotor area (PMA)Medial region  Supplementary motor area (SMA);Motor maps present in all regions: PMA –sensory-guided movements; SMA – internally-guided movementsPrimary Motor Cortex Organization1. Somatotopic organization of precentral gyrus (like postcentral gyrus);2. Contralateral representationPlanning of Voluntary MovementsThe Contributions of Posterior Parietal and Prefrontal Cortex:Represent highest levels of motor controlDecisions made about actions and their outcomeArea 5: Inputs from areas 3, 1, and 2Area 7: Inputs from higher-order visual cortical areas such as