Motor System Overview

A system that controls voluntary, precise, and coordinated movements.

Movement disorders often appearing in psychiatric patients due to medication side effects.

Brain cells initiating movements from the cortex.

Brain cells connecting to muscles to enable movement.

Damage to UMN resulting in spasticity, exaggerated reflexes, and positive Babinski sign.

Damage to LMN resulting in flaccid paralysis, muscle atrophy, and loss of reflexes.

Brain pathway controlling fine voluntary movements.

Brain region crucial for movement coordination.

Initiates and regulates movement by receiving input from the cerebral cortex and sending output via the thalamus back to the cortex. It has two pathways: direct to facilitate and indirect to inhibit movement.

Damage to dopamine-producing neurons in the substantia nigra, leading to overactivity in the basal ganglia's inhibitory pathways.

Basal ganglia plans movement—cognitive aspect—while the cerebellum refines and coordinates the ongoing actions—real-time adjustment.

The basal ganglia are composed of caudate, putamen, globus pallidus, subthalamic nucleus, and substantia nigra.

The basal ganglia receive primary input from the cerebral cortex and send output through the thalamus back to the cortex. This process of sending information back and forth is crucial to the coordinated planning and execution of motor tasks

The deep cerebellar nuclei receive inhibitory signals from Purkinje cells and send excitatory signals to various brain regions, such as the thalamus, red nucleus, and vestibular nuclei, modulating motor control and coordination.

The cerebellum is organized into midline (trunk control), paravermal (limbs), and lateral (digits) zones.

Signal from various brain sources, like cerebral cortex and spinal cord, to granule cells in the cerebellar cortex

Originate from inferior olivary nucleus and have strong excitatory input to Purkinje cells, creating complex spikes.

Cerebellar dysfunction results in ataxia (uncoordinated movement), tremors, slurred speech, hypotonia, and postural issues such as the contra-lateral face turn and lowered ipsilateral shoulder.

Outputs from the deep nuclei (dentate, globose, emboliform, fastigial) influence motor control, coordinating actions, and adjusting learned movements.

The cerebellum plays a crucial role in motor learning, balance, posture, fine tuning motor commands, prevents excessive correction of movements, and coordinates movements

In mild cerebellar dysfunction, visual cues play an extremely important role for smooth and purposeful movements.

System controlling voluntary, complex movements, carefully timed and coordinated.

Movement disorders often linked to psychiatric patients or medication side effects.

Adjusts movements by comparing intended vs. actual movements.

Anticipates and adjusts for rapid movements using past experience.

Brain cells initiating movement from the cortex.

Brain cells connecting to muscles to enable movement.

Brain pathway controlling fine, voluntary movements.

Influence posture and reflexive movements.

Brain region crucial for movement coordination and adjusting actions.

Sequence of movements planned in premotor and supplementary motor areas, to 1° motor cortex.

The deep cerebellar nuclei receive inhibitory signals from Purkinje cells and send excitatory signals to various brain regions (thalamus, red nucleus, vestibular nuclei), influencing motor control and coordination.

The cerebellum is organized into midline (trunk control), paravermal (limbs), and lateral (digits) zones.

Weak excitatory input from various sources (cortex, spinal cord, brainstem) to granule cells in the cerebellar cortex.

Strong excitatory input from the inferior olivary nucleus directly to Purkinje cells, creating complex spikes.

Symptoms include ataxia (uncoordinated movement), tremors, slurred speech, hypotonia, and postural issues like a contra-lateral face turn and ipsilateral shoulder drop.

In mild cases, visual cues are crucial for purposeful movements.

The deep nuclei (dentate, globose, emboliform, fastigial) send output, coordinating movements and adjusting learned ones.

The four deep nuclei of the cerebellum: dentate, globose, emboliform, and fastigial.

Outputs from the deep nuclei coordinate actions, adjust learned movements, and reduce over-corrections.

The cerebellum plays a crucial role in coordinating movement, balance, posture, timing, precise motor commands, motor learning, and preventing overcorrections.

The basal ganglia initiate and regulate movement, receiving input from the cortex and sending output back through the thalamus. Two main pathways, direct (facilitating) and indirect (inhibiting), work together for coordinated movement.

Parkinson's is caused by damage to dopamine-producing neurons in the substantia nigra, leading to overactivity of inhibitory pathways within the basal ganglia.

Basal ganglia plan movement (cognitive) while the cerebellum coordinates and refines ongoing movements (real-time adjustments).

The basal ganglia's five main components are the caudate, putamen, globus pallidus, subthalamic nucleus, and substantia nigra.

The basal ganglia receive their main input from the cerebral cortex and send output through the thalamus, connecting back to the cortex.

Parkinson's shows tremors, stiffness, slow movement, and an expressionless facial appearance.

Indirect pathway within the basal ganglia suppresses unneeded movements by increasing inhibition.

Direct pathway within the basal ganglia facilitates movement by reducing inhibition.

Lesions in the basal ganglia can cause either hyperkinetic (excessive movement) or hypokinetic (reduced movement) disorders.

Alcohol and thiamine deficiency can often affect the Basal Ganglia.