Neuromotor Basis For Motor Control Flashcards
Central nervous system
Brain and spinal cord
Neuromotor system
Components of the CNS and PNS involved in control of coordinated movement
Neuron
Nerve cell
Parts of the neuron
Cell body (contains nucleus)
Dendrites (receive info)
Axon
3 types of neurons
Sensory
Interneuron
Motor neuron
Sensory neuron
Afferent (arriving at brain)
- send info to CNS from sensory receptors
Unipolar : 1 axon, no dendrites
Motor neurons
Effferent
Alpha motor neurons
From spinal cord to extrafusal muscle fibers (skeletal muscle fibers contracting)
Gamma motor neurons
From spinal cord to intrafusal muscle fibers (specialized skeletal muscles for proprioception)
Interneurons
- communication between neurons
- within spinal cord
How does an interneuron between afferent and efferent work
Sensory detects heat afferent - interneuron- efferent - muscle contracts withdraws finger
4 areas associated with motor control in brain
Diencephalon
Cerebrum
Brainstem
Cerebellum
Two halves of Cerebrum
Right and left cerebral hemispheres with corpus callosum between
What’s the cerebrum covered by
Cerebral cortex
Cortical lobes of the cerebrum
Frontal
Parietal
Occipital
Temporal
Location of the primary motor cortex
Anterior to central sulcus
Dorsal portion of frontal lobe
function of primary motor cortex
- initiate and coordinate movements
- control fine motor skills
- control and learn postural coordination
Location of somatosensory cortex
Posterior to central sulcus
Function of somatosensory cortex
- receive sensory info from body
- association areas integrate cognitive, sensory and motor signals
Location of pre motor cortex
Frontal lobe, anterior to primary motor cortex
Function of pre motor cortex
- organization of movements before initiation
- involved in observational learning
- selecting voluntary movements (simple)
Mirror neurons
Visuomotor neurons within premotor cortex that activate when observing movement
Location of supplementary motor area (SMA)
Medial surface of frontal lobe anterior to portions of primary motor cortex (above premotor)
Function of supplementary motor area
- controls movement sequences
- coordinates movement between limbs
- controls posture
- involved in control of complex movements
Location of parietal lobe
Posterior to central sulcus
Anterior to occipital lobe
Function of parietal lobe
- perception of sensory input (taste, touch, temp, pain)
- integration of sensory input with movement prep and execution (integration with premotor, primary motor and SMA cortexes before and during movement)
- involved in speech production and language processing
Location of basal ganglia
Below cerebral hemispheres
Function of basal ganglia
- manage voluntary movement (planning and initiation)
- motor learning and adaptation
- control size of movement
- involved in cognition
2 parts of diencephalon
Thalamus and hypothalamus
Location of thalamus
- superior to brainstem between cortex and midbrain
Function of thalamus
- relay station
- involved in control of attention, mood, perception of pain, consciousness, sleep, alertness
- connects with cortex and midbrain
Location of hypothalamus
- below thalamus
- part of limbic system
Function of hypothalamus
- control of endocrine system and body homeostasis
Two pathways of basal ganglia
Direct and indirect
Direct pathway of basal ganglia
- makes movement
- facilitates movement by removing inhibition of thalamus
- allows thalamus to be more active to transport signal to motor cortex then muscles
Indirect pathway of basal ganglia
- inhibits movements
- prevents unwanted movement by increasing inhibition of thalamus
Location of cerebellum
- attached to brainstem
- inferior to occipital lobe
Function of cerebellum
- control of smooth and accurate movements
- motor learning
What are the functions of cerebellum involving motor learning
Error detection and correction system
Eye-hand coordination, movement timing, and posture
Planning movement
Involved in speech production
What is it called when a person has no cerebellum
Primary cerebellar a genesis
What is affected by cerebellar a genesis
Walking and balance, speech and arm movements
Why is their mild or moderate motor deficiency from primary cerebellar agenesis
Extra cerebellar motor system plasticity
3 parts of brainstem involved in motor control
Pons
Medulla oblongata
Reticular formation
Location of pons
Middle of brain stem
Function of pons
- bridge between cerebral cortex and cerebellum
- involved in control of various body functions (chewing, bladder control, sleep cycles)
- involved in balance control
Location of medulla oblongata
Lowest portion of brain stem below pons
Function of medulla oblongata
- regulatory center for internal physiologic process (breathing, heartbeat, BP)
- cross over point for many neural pathways (tracts)
Location of reticular formation
Throughout brainstem
Function of reticular formation
- integrates sensory and motor info
- inhibits/excites neural signals to skeletal muscle
What is Parkinson’s disease
Basal ganglia dysfunction
- decreased dopamine neurons in basal ganglia and formation of proteins
Progressive and terminal
Cause of Parkinson’s
Unknown etiology
Cardinal features of Parkinson’s
- Slow movements (bradykinesia)
- Resting tremor
- Rigidity (tight muscles)
- Postural instability
Premotor symptoms of Parkinson’s
- loss of smell
- constipation
- REM sleep behaviour disorder
- can be ongoing for 5-15 years before motor symptoms
Gait in Parkinson’s
Stiff, shuffling, slow
Lack of arm swing
Forward stooped posture
Festination during stopping
Freezing of gait
Stroke
Damage to brain caused by an interruption to brains blood flow (aneurysm, blockage)
Recovery from stroke includes
Natural recovery
Relearning skills (plasticity of CNS)
- depends on location of stroke
Multiple sclerosis
Disease caused by inflammation and damage to the myelin covering nerves
- impairs communication between cells
How is MS diagnosed
MRI
Symptoms of MS
Fatigues
Weakness
Lack of coordination
Impaired sensation, vision, and bladder control
Cognitive changes
Mood changes
