MOTOR SYSTEMS POSTURE AND LOCOMOTION D C MIKULECKY

MOTOR SYSTEMS: POSTURE AND LOCOMOTION D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY AND FACULTY MENTORING PROGRAM

CONTROL OF POSTURE BY THE BRAIN STEM z. THE VENTROMEDIAL PATHWAY z. THE LATERAL RETICULOSPINAL TRACT z. THE RUBROSPINAL TRACTH

BRAIN STEM CENTERS FOR MOTOR CONTROL TECTUM LATERAL RETICULAR FORMATION LATERAL AND MEDIAL VESTIBULAR NUCLEI RED NUCLEUS MEDIAL RETICULAR FORMATION

THE VENTROMEDIAL PATHWAY z VESTIBULOSPINAL TRACT: CARRIES INFORMATION FROM VESTIBULAR NUCLEUS FOR REFLEX CONTROL OF EQUILIBRIUM z TECTOSPINAL TRACT: ORIGINATES IN TECTUM FOR CONTROL OF HEAD AND EYE MOVEMENTS z MEDIAL RETICULOSPINAL TRACT: ORIGINATES IN RETICULAR FORMATION FOR MAINTAINING POSTURE BY ACTIVATION OF EXTENSORS

PATHWAYS FROM BRAINSTEM FOR MOTOR CONTROL: VENTROMEDIAL TECTOSPINAL TRACT VESTIBULOSPINAL TRACTS RETICULOSPINAL TRACT

LOCATION OF CELL BODIES FOR EXTENSORS AND FLEXORS EXTENSORS

THE LATERAL RETICULOSPINAL TRACT z. FROM LATERAL RETICULAR NUCLEUS z. DESCEND IN LATERAL REGION OF THE SPINAL CORD

PATHWAYS FROM BRAINSTEM FOR MOTOR CONTROL: LATERAL RETICULOSPINAL TRACT

THE RUBROSPINAL TRACTH z. FIBERS ORIGINATE IN RED NUCLEUS z. DESCEND ALONG DORSAL AND LATERAL BORDERS OF CORD z. INNERVATE DISTAL FLEXOR MUSCLES

PATHWAYS FROM BRAINSTEM FOR MOTOR CONTROL: RUBROSPINAL

SUMMARY OF CONTROL OF SPINAL MOTOR NEURONS BY BRAIN STEM LATERAL RETICULOSPINAL TRACT RUBROSPINAL TRACT (-) (+) TO FLEXORS TO EXTENSORS (-) ( (+) ) VENTROMEDIAL PATHWAY TO FLEXORS TO EXTENSORS

THE MOTOR CORTEX z. ORGANIZATION z. DESCENDING PATHWAYS z. SENSORY FEEDBACK z. CORTICAL CODING OF REACHING MOVEMENTS

ORGANIZATION OF THE MOTOR CORTEX z. CORTICAL EFFERENT ZONES: VERTICAL COLUMNS OF CELLS z. EACH ZONE CONTROLS ONE MUSCLE z. SIX DIFFERENT LAYERS OF CELLS z. OUTPUT LAYER IS LAYER V z. EXCITE BOTH ALPHA AND GAMMA MOTOR NEURONS

CORTICAL AREAS INVOVED IN MOTOR CONTROL

SOMATOTOPIC ORGANIZATION OF THE MOTOR CORTEX

DESCENDING PATHWAYS FROM THE MOTOR CORTEX z. CORTICOSPINAL PATHWAY z. CORTICOBULBAR PATHWAY z. PYRAMIDAL TRACT z. LATERAL CORTICOSPINAL TRACT

PATHWAYS FROM CORTEX FOR MOTOR CONTROL: LATERAL CORTICOSPINAL TRACT DORSAL COLUMN NUCLEI PREMOTOR AREA RED NUCLEUS 1 2 3 PYRAMIDAL TRACT 4 6 PRIMARY MOTOR CORTEX

PATHWAYS FROM CORTEX FOR MOTOR CONTROL: CORTICOSPINAL TRACTS LATERAL CORTICOSPINAL TRACT DORSAL COLUMN NUCLEI PREMOTOR AREA RED NUCLEUS 1 2 3 VENTRAL CORTICOSPINAL TRACT PYRAMIDAL TRACT 4 6 PRIMARY MOTOR CORTEX

SENSORY FEEDBACK TO THE MOTOR CORTEX z. VIA SOMATIC SENSORY CORTEX z. CONNECTED IN A TOPOGRAPHIC MANNER z. MONITOR MOVEMENT AND SMOOTH AND CORRECT

CORTICAL CODING OF REACHING MOVEMENTS z. DYNAMIC NEURONS CODE FOR RATE OF FORCE DEVELOPMENT z. STEADY STATE FORCE z. NEURONS CONTROLLING RATE AND DIRECTION OF MOVEMENT ARE DISTRIBUTED (NO ONE NEURON HAS ALL THE INFORMATION)

SUPPLIMENTAL MOTOR AREAS PROGRAM MOVEMENT z. HYPOTHALAMUS INVOLVED IN MOTIVATIONAL FACTORS z. TRANSMIT INFORMATION TO SUPPLIMENTAL AND PREMOTOR CORTEX z. HERE THE DESIGN OF THE MOVEMENT IS EXECUTED z. REHERSAL OF MOVEMENTS AS WELL

POSTERIOR PARIETAL CORTEX INTEGRATES SENSORY STIMULI FOR PURPOSEFUL MOVEMENT z. RECEIVES BOTH SOMATIC AND VISUAL SENSORY INFORMATION z. TRANSMITS IT TO SUPPLIMENTAL AND PREMOTOR AREAS

CORTICAL AREAS INVOVED IN MOTOR CONTROL

THE CEREBELLUM AND BASAL GANGLIA COORDINATE MOVEMENTS z. THE CEREBELLUM IS INVOLVED IN PLANNING, COORDINATION, AND POSTURE z. ANTERIOR AND POSTERIOR LOBES INVOLVED IN LIMB MOVEMENT z. FLOCCULONODULAR LOBE IS INVOLVED IN EQUILIBRIUM AND POSTURE

FUNCTIONS OF THE CEREBELLUM z. PLANNING OF A MOVEMENT z. CONTROL OF POSTURE AND EQUILIBRIUM z. CONTROL OF SMOOTH LIMB MOVEMENT

CELL TYPES AND CIRCUITS IN THE CEREBELLUM

PURKINJE CELLS ARE THE MOST PROMINENT OF ALL THE CEREBELLAR CELL TYPES z. TWO INPUTS: CLIMBING FIBERS (FROM OLIVARY NUCLEUS) AND PARALLEL FIBERS FROM GRANULE CELLS z. 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 z. PRIMARY INPUT FROM NEOCORTEX z. OTHER INPUTS FROM THE THALAMUS AND SUBSTANTIA NIGRA z. GLOBUS PALLIDUS PROVIDES OUTPUT z. COGNITIVE FUNCTIONS

BASAL GANGLIA: AFFERENT CONNECTIONS CORTEX CAUDATE THALAMUS PUTAMEN SUBSTANTIA NIGRA

BASAL GANGLIA: INTRINSIC CONNECTIONS CORTEX CAUDATE THALAMUS PUTAMEN GLOBUS PALLIDUS SUBSTANTIA NIGRA

BASAL GANGLIA: EFFERENT CONNECTIONS CAUDATE THALAMUS PUTAMEN GLOBUS PALLIDUS SUBSTANTIA NIGRA

BASAL GANGLIA OUTPUT TO CORTEX VIA THALAMUS z. MODULATE DESCENDING COMPONENTS OF THE MOTOR SYSTEM z. ADDITIONAL OUTPUTS TO SUBSTANTIA NIGRA USE DOPAMINE AS NEUROTRANSMITTER: THESE DEGENERATE IN PARKINSON’S DISEASE

THE VESTIBULAR APPARATUS z. SEMICIRCULAR CANALS: HAIR CELLS SENSE MOTION z. THREE COORDINATE PLANES: SUPERIOR, INFERIOR, AND HORIZONTAL z. UTRICLE AND SACCULE DETECT LINEAR ACCELERATION IN HORIZONTAL AND VERTICLE PLANES

DISEASES OF THE MOTOR SYSTEM z. UPPER-MOTOR-NEURON LESIONS z. CORTICOSPINAL TRACT LESIONS z. LOWER MOTOR NEURON LESIONS z. CEREBELLAR LESIONS

UPPER-MOTOR-NEURON LESIONS z. PARALYSIS ON SIDE OF BODY OPPOSITE LESION z. INCREASED MUSCLE TONE z. EXTENSION OF BIG TOE AND BABINSKI SIGN z. LACK OF MUSCLE ATROPHY

CORTICOSPINAL TRACT LESIONS z. LOSS OF STRENGTH AND MOVEMENT OF MUSCLE GROUPS z. LOSS OF STRENGTH IN VOLUNTARY MUSCLE CONTRACTION z. BABINSKI SIGN

LOWER MOTOR NEURON LESIONS z. IPSOLATERAL HYPOACTIVE REFLEXES z. PARALYSIS z. FLACID MUSCLES WITH PROMINENT ATROPHY

CEREBELLAR LESIONS z. IPSILATERAL DISTURBANCES z. LATERAL LESIONS RESULT IN COORDINATION LOSS z. LESIONS IN THE VERMIS PRODUCE ATAXIA (LOSS OF COORDINATION) z. FLOCCULONODULAR LOBE LESIONS PRODUCE EQUILIBRIUM DISTURBANCE AND ATAXIA