Premotor cortex Damage to descending motor pathways Friday

  • Slides: 10
Download presentation
Premotor cortex Damage to descending motor pathways Friday Jan. 27 03 -55 -485 1

Premotor cortex Damage to descending motor pathways Friday Jan. 27 03 -55 -485 1

Friday Jan. 27 03 -55 -485 2

Friday Jan. 27 03 -55 -485 2

Premotor cortex -movement selection • Reciprocal connections • with the primary motor cortex •

Premotor cortex -movement selection • Reciprocal connections • with the primary motor cortex • And project axons through corticobulbar and corticospinal pathways • Uses information from other cortical regions • Active during association of visual (sensory) to movement. Friday Jan. 27 03 -55 -485 3

Lateral premotor cortex • Cell activity associated with movement in a particular direction. •

Lateral premotor cortex • Cell activity associated with movement in a particular direction. • For conditional motor tasks, cells become active at the appearance of a cue. • Before the signal to make the movement Friday Jan. 27 03 -55 -485 4

Lateral premotor cortex • Encode a monkey’s intention to perform a particular movement. •

Lateral premotor cortex • Encode a monkey’s intention to perform a particular movement. • Involved in the selection of movements based on external events. Friday Jan. 27 03 -55 -485 5

Lateral premotor cortex • If lesioned – --> monkey has difficulty performing visually cued

Lateral premotor cortex • If lesioned – --> monkey has difficulty performing visually cued conditional tasks. Friday Jan. 27 03 -55 -485 6

Lateral premotor cortex • Patients with frontal lobe damage: – Difficulty learning to select

Lateral premotor cortex • Patients with frontal lobe damage: – Difficulty learning to select a particular movement to be performed in response to a visual cue. Friday Jan. 27 03 -55 -485 7

Medial premotor cortex • Mediates internal cues to movement initiation. • f. MRI scans

Medial premotor cortex • Mediates internal cues to movement initiation. • f. MRI scans in humans: activated when subjects perform movements from memory. Friday Jan. 27 03 -55 -485 8

Damage to descending motor pathways • Upper Motor Neuron Syndrome – Damage to cortex

Damage to descending motor pathways • Upper Motor Neuron Syndrome – Damage to cortex or anywhere along the descending tracts – --> muscles contralateral side become flaccid on limbs and face. – Brainstem preserves trunk muscles Friday Jan. 27 03 -55 -485 9

Babinski sign • Maturation of corticospinal pathway • An indicator of damage to descending

Babinski sign • Maturation of corticospinal pathway • An indicator of damage to descending upper motor neuron pathways. Friday Jan. 27 03 -55 -485 10

Motor cortex Organization of motor cortex Motor corticalMotor cortex Organization of motor cortex Motor cortical
Motor cortex Organization of motor cortex Motor corticalMotor cortex Organization of motor cortex Motor cortical
Motor Skills Motor Cortex Anatomy The motor cortexMotor Skills Motor Cortex Anatomy The motor cortex
Premotor cortex brainstem and emotional motor system DominaPremotor cortex brainstem and emotional motor system Domina
Motor cortex Somatosensory cortex Sensory associative cortex ParsMotor cortex Somatosensory cortex Sensory associative cortex Pars
Motor cortex Somatosensory cortex Sensory associative cortex ParsMotor cortex Somatosensory cortex Sensory associative cortex Pars
Motor cortex Somatosensory cortex Sensory associative cortex ParsMotor cortex Somatosensory cortex Sensory associative cortex Pars
Motor cortex Somatosensory cortex Sensory associative cortex ParsMotor cortex Somatosensory cortex Sensory associative cortex Pars
THE DESCENDING MOTOR TRACTS The descending tracts mayTHE DESCENDING MOTOR TRACTS The descending tracts may