Exam 3 final review Flashcards
Inputs of Striatum
Cerebral cortex - GABA (inhibitory)
Substantia Nigra - Pars Compacta - Excitatory or Inhibitory (Dopamine)
Outputs of Striatum
Globus Pallidus
Substantia Nigra - Pars reticulata
Inputs of Globus Pallidus
Striatum - Inhibitory (GABA)
Subthalamic Nucleus - Excitatory (Glutamate)
Outputs of Globus Pallidus
Internal Segments - Striatum
External Segments - Subthalamic Nucleus
Input of Subthalamic Nucleus
Globus Pallidus - External Segments - Inhibitory (GABA)
Output of Subthalamic Nucleus
Globus Pallidus - Internal Segment
Inputs of Substantia Nigra
Striatum - Inhibitory (GABA)
Globus Pallidus - Inhibitory (GABA)
Outputs of Substantia Nigra
Pars Compacta - Striatum - Modulates inputs from the cerebral cortex
Pars Reticulata - Superior Colliculus - Neural control of saccade
Dendritic tree of Purkinje Layer
Projects into molecular layer, receives input from Parallel fibers of Granule cells and afferent climbing fibers
Axon of Purkinje Layer
Projects into vestibular or cerebellar nuclei
Purkinje cells
Only efferent neurons of the cortex: leaving the cerebellar cortex
Superior Peduncles
Output to the thalamus and brainstem (motor cortices and upper motor neurons)
Middle Peduncles
Input from the pontine nuclei (from the motor cortices)
Inferior Peduncles
Input from the brainstem and spinal cord (sensory)
Pontine Nuclei
Information about intended movement
Internal feedback
Sensory input to the cerebellum
Information about actual movement
external feedback
Inferior Olivary Nucleus receives input from
Cerebral cortex, brainstem, and spinal cord
Output of Cerebellum
Motor Cortex
Brainstem
no direct output to the lower motor neurons of the brainstem and spinal cord
Input of Primary somatomotor cortex
Premotor cortex
Primary somatosensory cortex & posterior parietal cortex
Basal ganglia & cerebellum
Output of Primary somatomotor cortex
descending system
Input of Premotor cortex
Prefrontal cortex
Primary somatosensory cortex & posterior parietal cortex
Output of Premotor cortex
Primary motor cortex
Brainstem
Spinal Cord
Input of Posterior Parietal Cortex
Primary Somatosensory cortex
visual association cortex
Output of Posterior Parietal Cortex
Primarily premotor cortex
Origin of Corticospinal
Primary Somatomotor Cortex
Premotor and supplementary motor areas
Primary Somatosensory cortex
Superior Parietal Lobule
Cingulate Gyrus
Hypokinetic
- lack of disinhibition of the thalamus by the direct pathway
- Increased inhibition of the thalamus by the indirect pathway
Hyperkinetic
Disruption of the indirect pathway
Input of Vestibulocerebellum
Vestibular neuron & nuclei, visual
Output of Vesstibulocerebellum
Vestibular nuclei, Reticular nuclei, superior colliculus
Input of Cerebrocerebellum
Pontine Nuclei, Inferior Olive Nucleus
Output of Cerebrocerebellum
Motor cortices, Red nucleus
Outputs of Cerebellar cortex
- Motor Cortices
- Brainstem
Dysdiadochokinesia
unable to sustain a regular rhythm or produce an even force
Akinesia
Impairment of initiation of movement
Oculomotor Loop is involved in?
Control of saccades, by releasing the superior colliculus from inhibition
Prefrontal loop has which two separate pathways? and what are they involved in?
- Dorsolateral Prefrontal - initiation and termination of cognitive processes
- Lateral Orbitofrontal - mediation of empathic and socially approriate behavior
Ballismus
Hyperkinetic Disturbances
Which category of movement is adaptable to changes in behavioral goals?
Reflexive
Which category of movement can be improved with experience?
Voluntary
What does neural noise limit?
Accuracy of sensory input and motor output
What is the elementary unit of motor control?
Motor Unit
Muscle unit doesn’t have?
Alpha motor neuron
What does alpha motor neuron innervate?
Extrafusal skeletal muscle fibers
Where does alpha motor neuron terminate?
Neuromuscular junctions on skeletal muscle fibers
LMNs that innervate axial muscles are?
Medial
LMNs that innervate distal muscles are?
Lateral
LMNs that innervate flexors are?
Dorsal
LMNs that innervate extensors are?
Ventral
Signs of Lower Motor Neuron Damage
Flaccid Paralysis
Fibrillation
Hypotonia
Hyporeflexia
What are the contractile unit of striated muscle fibers?
Sarcomeres
What structure encircle myofibrils?
T-Tubules
What structure surrounds individual myofibrils?
SR
Each muscle fiber is surrounded by?
Endomysium
Skeletal muscles are surrounded by?
Epimysium
Muscle force varies with?
Direction and rate of change
What is the efferent innervation of muscle spindle?
Gamma Motor Neurons
What does Alpha-Gamma Coactivation allow?
Muscle spindles to maintain their sensitivity to changes of muscle length during muscle contraction
What structure detect change in muscle length and rate of change of muscle length?
Muscle Spindle
What is the primary source of input to alpha motor neurons?
Spinal Interneurons
Reflexes are mediated through which pathways?
Spinal and supraspinal pathways
What is the motor response of Myotatic
Contraction of the stretched muscle
What is the Motor Response of GTO Circuit?
Relaxation of the tense muscle
Myotatic Reflex
Collaterals of Type Ia sensory neurons
Volitional Movement
Collaterals of descending axons
What is the main function of reciprocal innervation?
Enhances speed and efficiency
What amplifies the sensory input?
Divergence
What increases the flexibility of reflex responses?
Convergence
Modulation of Local Spinal Circuits can occur at which three sites?
Alpha Motor neurons
Interneurons in polysynaptic pathways
Afferent axon terminals
Muscle TOne is based on?
Intrinsic stiffness of muscle
Myotatic reflex loop
Rhythm Generataor
Flexor & Extensor Half Centers- generating inhibitory interneurons
Brainstem Centers
Initiates and regulates the speed of walking
Cerebellum
Regulates the timing and intensity of the descending input, coordinating the stepping movements
Motor Cortex
Plans, initiates, and executes voluntary movemenets
Motor Response of Corneal Blink Reflex
Contraction of the orbicularis oculi resulting in eyelid closure
Input of Upper Motor Neurons
Brainstem
Cerebral Cortex
Cerebellum
Maintaining Support Against Gravity is controlled at?
Spinal Cord Level
Maintaining Balance is controlled at
subcortical and cortical levels
Extend base of support
stepping or using the upper limb
What is Somatosensory System important for?
Timing and direction of responses
Vestibular System is important for?
Balance on unstable surfaces and during head movements
Cerebellum is interconnected with?
vestibular nuclei and reticular formation
Pontine Reticular Formation
Horizontal Movement
Mesencephalic Reticular Formation
Vertical movements
What neuron gives rise to the pulse of ocular motor nuclei?
Burst
Function of Superior Colliculus
Directs reflexive orienting movements of the eyes and head
Function of Frontal Eye Fields
Direct Voluntary and memory guided eye movements
What does Basal Ganglia inhibit?
Superior Colliculus