The Motor System Flashcards
What is the motor system
-extremely complex system
- includes parts of the motor system that control voluntary movement, allowing thought to be turned into movement
The type of motor speech disorder depends on?
Location & extent of damage to the motor system
Two main components of the motor system?
Central Nervous System & Peripheral Nervous System
The CNS consists of?
The brain and spinal cord
The PNS consists of?
-12 pairs of cranial nerves
-31 pairs of spinal nerves
What is the most complex and important part of the nervous system?
The brain
Function of the brain?
-initiates or controls actions- almost all nervous system activity originates in or is processed by the brain
-Brain sends motor commands
-Brain receives sensory commands and controls cognitive functions
Voluntary motor commands go in what direction
Descending
Away from the CNS
Sensory commands go in what direction
Ascending
Accessing the CNS
Primary divisions of the brain?
- Cerebrum
- Brain stem
- Cerebellum
What is the largest and most prominent part of the brain
The cerebrum
Division of the cerebrum?
-Divided into 2 hemispheres by the longitudinal fissure
-Consists of 4 lobes
What are the primary lobes of the cerebrum
-frontal lobe
-temporal lobe
-parietal lobe
-occipital lobe
What are the 2 additional cerebrum lobes?
-insular lobe
-limbic system
What is the surface of the cerebrum called?
Cerebral cortex
The cerebral cortex is known as ___, why?
Gray matter
It is called this because of its color. Soma’s (or cell bodies) are present in the cerebral cortex, giving it a pinkish-gray color.
Function of the cerebral cortex
Higher order functioning
Responsible for consciousness, thought, and cognitive activities (motor planning, problem solving, sensory perception, and language)
The surface of the cerebrum consists of what?
Sulci, which are the grooves or indentations
Gyri, which are the projections or humps
What are the two main sulci on the cerebrum
Lateral sulcus- separating the frontal lobe from the temporal lobe
Central sulcus- separating the frontal lobe from the parietal lobe
What are the two main gyri on the cerebrum
Precentral gyrus = primary motor cortex = motor strip
Postcentral gyrus = primary sensory cortex = sensory strip
Main function of the primary motor cortex
Sends out motor signals for motor movement
Main function of the primary sensory cortex
Receives all sensory information
Where is the brainstem located?
Between the cerebrum and the spinal cord
What structures make up the brainstem
Midbrain
Pons
Medulla oblongata
Which nerves originate in the brainstem area?
Cranial nerve pairs 3 through 12
What is the attachment point for the brainstem to the cranial nerve?
The cranial nerve nuclei
Function of the brainstem
- passageway for descending and ascending neural tracts traveling between the cerebrum and spinal cord
- controls certain integrative and reflexive actions (such as automatic body functions, respiration, and consciousness)
- conveys motor impulses from the CNS to the articulation muscles (larynx, face, tongue, pharynx, and velum)
Which structure is attached to the back of the brainstem?
Cerebellum
Divisions of the cerebellum
-Divided into two lobes by a fissure (like the cerebrum)
-Vermis is a mass of tissue connecting the two cerebellum lobes
Function of the cerebellum
-coordinates voluntary movements so the muscles contract with correct force at the appropriate times
-Makes neural connections with cerebrum/cerebral cortex and other parts of the brain
The cerebellum regulates …?
-Muscle tone
-maintenance of balance
-coordination of skilled motor movements
-posture
-support
-equilibrium
What is the process to initiating a voluntary movement?
10 steps
-Desire to move
-Association cortex
-Basal ganglia
-Cerebellum
-Thalamus
-Primary Motor Cortex
-Pyramidal system
-Extrapyramidal system
-Cranial and Spinal nerve nuclei
-Neuromuscular junction
What is the first step to produce a voluntary movement?
The desire to move- you must first think and desire to produce any voluntary movement
What structure/system initiates the plan to move? Explain this
The association cortex
Here, the association cortex makes sense of sensory information and creates the initial, rough gross movement plan sequence
The association cortex consists of?
4 areas of corticies
What would be an example of an initial rough gross motor plan sequence
After having the desire to pick up a pencil, recognizing that some amount of grip is needed to pick up the pencil
The basal ganglia consists of what 3 structures?
-caudate nucleus
-putamen
-global pallidus
How does the basal ganglia assist in the production of a voluntary movement
It serves as the link between the association cortex and the PMC
It refines the planning of slow and continuous movement to occur in a controlled manner
If the basal ganglia is impaired what can happen?
-Hyperexcited neurons in the basal ganglia (increased activity) can lead to hypokinetic dysarthria
-Degenerating neurons in the basal ganglia (cell death/less activity) can lead to hyperkinetic dysarthria