MOTOR SYSTEMS:POSTURE AND LOCOMOTION

D. C. MIKULECKYPROFESSOR OF PHYSIOLOGY

ANDFACULTY MENTORING PROGRAM

CONTROL OF POSTURE BY THE BRAIN STEM

THE VENTROMEDIAL PATHWAY

THE LATERAL RETICULOSPINAL TRACT

THE RUBROSPINAL TRACTH

BRAIN STEM CENTERS FOR MOTOR CONTROL

RED NUCLEUSLATERALRETICULARFORMATION

LATERAL AND MEDIALVESTIBULARNUCLEI

MEDIAL RETICULAR FORMATION

TECTUM

THE VENTROMEDIAL PATHWAY

VESTIBULOSPINAL TRACT: CARRIES INFORMATION FROM VESTIBULAR NUCLEUS FOR REFLEX CONTROL OF EQUILIBRIUM

TECTOSPINAL TRACT: ORIGINATES IN TECTUM FOR CONTROL OF HEAD AND EYE MOVEMENTS

MEDIAL RETICULOSPINAL TRACT: ORIGINATES IN RETICULAR FORMATION FOR MAINTAINING POSTURE BY ACTIVATION OF EXTENSORS

PATHWAYS FROM BRAINSTEM FOR MOTOR CONTROL: VENTROMEDIAL

VESTIBULO-SPINALTRACTS

RETICULO-SPINALTRACT

TECTO-SPINALTRACT

LOCATION OF CELL BODIES FOR EXTENSORS AND FLEXORS

FLEXORS

EXTENSORS

THE LATERAL RETICULOSPINAL TRACT

FROM LATERAL RETICULAR NUCLEUS

DESCEND IN LATERAL REGION OF THE SPINAL CORD

PATHWAYS FROM BRAINSTEM FOR MOTOR CONTROL:LATERAL RETICULOSPINAL TRACT

LATERALRETICULO-SPINALTRACT

THE RUBROSPINAL TRACTH

FIBERS ORIGINATE IN RED NUCLEUS

DESCEND ALONG DORSAL AND LATERAL BORDERS OF CORD

INNERVATE DISTAL FLEXOR MUSCLES

PATHWAYS FROM BRAINSTEM FOR MOTOR CONTROL: RUBROSPINAL

SUMMARY OF CONTROL OF SPINAL

MOTOR NEURONS BY BRAIN STEM

TO EXTENSORS

TO FLEXORS

RUBRO-SPINALTRACT

LATERAL RETICULO- SPINAL TRACT

(+)

(-)

(-)

(+)(-)

TO EXTENSORS

TO FLEXORS

VENTROMEDIAL PATHWAY

THE MOTOR CORTEX

ORGANIZATIONDESCENDING PATHWAYSSENSORY FEEDBACKCORTICAL CODING OF REACHING

MOVEMENTS

ORGANIZATION OF THE MOTOR CORTEX

CORTICAL EFFERENT ZONES: VERTICAL COLUMNS OF CELLS

EACH ZONE CONTROLS ONE MUSCLESIX DIFFERENT LAYERS OF CELLSOUTPUT LAYER IS LAYER VEXCITE BOTH ALPHA AND GAMMA

MOTOR NEURONS

CORTICAL AREAS INVOVED IN MOTOR CONTROL

SOMATOTOPIC ORGANIZATION OF THE MOTOR CORTEX

DESCENDING PATHWAYS FROM THE MOTOR CORTEX

CORTICOSPINAL PATHWAYCORTICOBULBAR PATHWAYPYRAMIDAL TRACTLATERAL CORTICOSPINAL TRACT

PATHWAYS FROM CORTEX FOR MOTOR CONTROL: LATERAL CORTICOSPINAL TRACT

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PREMOTORAREA

PRIMARYMOTORCORTEX

PYRAMIDALTRACT

DORSALCOLUMN NUCLEI

LATERALCORTICO-SPINALTRACT

REDNUCLEUS

PATHWAYS FROM CORTEX FOR MOTOR CONTROL: CORTICOSPINAL TRACTS

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PREMOTORAREA

PRIMARYMOTORCORTEX

PYRAMIDALTRACT

DORSALCOLUMN NUCLEI

LATERALCORTICO-SPINALTRACT

REDNUCLEUS

VENTRALCORTICO-SPINALTRACT

SENSORY FEEDBACK TO THE MOTOR CORTEX

VIA SOMATIC SENSORY CORTEXCONNECTED IN A TOPOGRAPHIC

MANNERMONITOR MOVEMENT AND SMOOTH

AND CORRECT

CORTICAL CODING OF REACHING MOVEMENTS

DYNAMIC NEURONS CODE FOR RATE OF FORCE DEVELOPMENT

STEADY STATE FORCENEURONS CONTROLLING RATE AND

DIRECTION OF MOVEMENT ARE DISTRIBUTED (NO ONE NEURON HAS ALL THE INFORMATION)

SUPPLIMENTAL MOTOR AREAS PROGRAM MOVEMENT

HYPOTHALAMUS INVOLVED IN MOTIVATIONAL FACTORS

TRANSMIT INFORMATION TO SUPPLIMENTAL AND PREMOTOR CORTEX

HERE THE DESIGN OF THE MOVEMENT IS EXECUTED

REHERSAL OF MOVEMENTS AS WELL

POSTERIOR PARIETAL CORTEX INTEGRATES SENSORY STIMULI FOR PURPOSEFUL MOVEMENT

RECEIVES BOTH SOMATIC AND VISUAL SENSORY INFORMATION

TRANSMITS IT TO SUPPLIMENTAL AND PREMOTOR AREAS

CORTICAL AREAS INVOVED IN MOTOR CONTROL

THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS

THE CEREBELLUM IS INVOLVED IN PLANNING, COORDINATION, AND POSTURE

ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT

FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE

FUNCTIONS OF THE CEREBELLUM

PLANNING OF A MOVEMENTCONTROL OF POSTURE AND

EQUILIBRIUMCONTROL OF SMOOTH LIMB

MOVEMENT

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES

TWO INPUTS: CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS

OUTPUT VARIES ACORDING TO INPUT: CLIMING FIBERS LEAD TO COMPLEX PATTERNS WHILE PARALLEL FIBERS GENERATE SIMPLE PATTERNS

THE BASAL GANGLIA

THE BASAL GANGLIA PLAN MOVEMENTS

PRIMARY INPUT FROM NEOCORTEXOTHER INPUTS FROM THE THALAMUS

AND SUBSTANTIA NIGRAGLOBUS PALLIDUS PROVIDES

OUTPUTCOGNITIVE FUNCTIONS

BASAL GANGLIA: AFFERENT CONNECTIONS

CORTEX

CAUDATE

THALAMUSPUTAMEN

SUBSTANTIANIGRA

BASAL GANGLIA: INTRINSIC CONNECTIONS

CORTEX

CAUDATE

THALAMUSPUTAMEN

SUBSTANTIANIGRA

GLOBUSPALLIDUS

BASAL GANGLIA: EFFERENT CONNECTIONS

CAUDATE

THALAMUSPUTAMEN

SUBSTANTIANIGRA

GLOBUSPALLIDUS

BASAL GANGLIA OUTPUT TO CORTEX VIA THALAMUS

MODULATE DESCENDING COMPONENTS OF THE MOTOR SYSTEM

ADDITIONAL OUTPUTS TO SUBSTANTIA NIGRA USE DOPAMINE AS NEUROTRANSMITTER: THESE DEGENERATE IN PARKINSON’S DISEASE

THE VESTIBULAR APPARATUS

SEMICIRCULAR CANALS: HAIR CELLS SENSE MOTION

THREE COORDINATE PLANES: SUPERIOR, INFERIOR, AND HORIZONTAL

UTRICLE AND SACCULE DETECT LINEAR ACCELERATION IN HORIZONTAL AND VERTICLE PLANES

DISEASES OF THE MOTOR SYSTEM

UPPER-MOTOR-NEURON LESIONSCORTICOSPINAL TRACT LESIONSLOWER MOTOR NEURON LESIONSCEREBELLAR LESIONS

UPPER-MOTOR-NEURON LESIONS

PARALYSIS ON SIDE OF BODY OPPOSITE LESION

INCREASED MUSCLE TONEEXTENSION OF BIG TOE AND

BABINSKI SIGNLACK OF MUSCLE ATROPHY

CORTICOSPINAL TRACT LESIONS

LOSS OF STRENGTH AND MOVEMENT OF MUSCLE GROUPS

LOSS OF STRENGTH IN VOLUNTARY MUSCLE CONTRACTION

BABINSKI SIGN

LOWER MOTOR NEURON LESIONS

IPSOLATERAL HYPOACTIVE REFLEXESPARALYSISFLACID MUSCLES WITH PROMINENT

ATROPHY

CEREBELLAR LESIONS

IPSILATERAL DISTURBANCESLATERAL LESIONS RESULT IN

COORDINATION LOSSLESIONS IN THE VERMIS PRODUCE

ATAXIA (LOSS OF COORDINATION)FLOCCULONODULAR LOBE LESIONS

PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA