Neural System of Motor Speech Flashcards
The nervous system is divided into the ___ and ___.
CNS
PNS
The CNS includes the ____ and ______.
Brain
Spinal Cord
The PNS includes parts of the nervous system that go ____ the brain and spinal cord. Also includes the _____ system and _____ system.
outside
Somatic System (cranial nerves/spinal nerves)
Automatic System
The most important cells of the nervous system.
Neurons
Means by which neural impulses are transmitted from one part of the nervous system to another.
Neurons
What are the 3 primary components of the neuron?
Cell body
Axon
Dendrites
Small substances released at end points (synaptic cleft) once charge reashes axon terminal
Neurotransmitters
What are 2 types of neurotransmitters?
Excitatory
Inhibitory
What are 2 important neurotransmitters in the motor system?
Acetylcholine (Ach)
Dopamine
______: junction between 2 neurons :: ______: junction between a neuron and a cell in the muscle
Synapse
Neuromuscular Junction
______: can be excitatory and inhibitory :: _____: is only excitatory and always uses ACH
Synapse
Neuromuscular Junction
Nuclei (Gray matter) makes up what 3 structures?
Cerebral Cortex
Subcortical Structures
Nuclei at brainstem
Types of Neurons
Motor Neurons (upper and lower)
Sensory Neurons
Interneurons
Bundles of axons : ____
fasciculi or tracts
Transmit impulses to other neurons/areas
tracts in CSN
transmit impulses from nerves to end organs
Nerves in PNS
The frontal lobe is in charge of …
the motor cortex, Broca’s area, executive functions, and personality
The temporal lobes are in charge of …
auditory cortex, Wernicke’s area and lang comp
Parietal Lobes are in charge of …
Sensory cortex
The occipital lobe is in charge of …
visual cortex
Cortices that first analyze sensory info
Primary Cortex : auditory, visual and sensory
cortex that receives planned motor impulses from cortical and subcortical areas of the brain
Primary motor cortex
Where does planning for voluntary movement originate in?
The association cortex
What occurs in the association cortices?
Different modalities are combined
attention is shifted
planning occurs
things are remembered
Where do the association cortices send rough sequence of motor impulses?
down to the subcortical structures for further processing and refining
- found in precentral gyrus
- somatotopically organized
- source for descending motor pathways
Primary Motor Cortex
Why is the primary motor cortex different from other primary cortices?
It is an actual commander; it receives neural motor impulses that have been processed, smoothed and coordinated
- postcentral gyrus
- primary receptor of general body sensations
- somatotopically arranged
Primary somatosensory cortex
primary motor cortex + primary sensory cortex = ?
sensorimotor area
What are the subcortical structures?
Basal Ganglia
Substantia Nigra
Subthalamic Nucleus
Diecephalon: Thalamus and Hypothalumus
What does the basal ganglia consist of?
The caudate nucleus, putamen and globus pallidus
What important role does the basal ganglia play?
Plans and refines slow, continuous movements.
Fuction of BG
has a dampening effect on cortical discharges and helps initiate movements
Damage to BG tends to result in …
excess involuntary movement or reduced movement
What structures influence the BG?
subcortical gray matter such as the substantia nigra and thalamus
If not enough dopamine is produced : it affects ________ :: if too much dopamine is produced : we _______
it affects gait and muscles become rigid; does not allow for smooth movements
we cannot control our movements
The thalamus is …
a doorway through which subcortical systems of nervous system communicate with cerebral cortex
Fuction of Thalamus
“a relay center”
receives neural inputs of planned motor movements from BG and cerebellum
may further refine motor impulses
The cerebellum receives neural impulses of intended movements from ….
the association cortices
How does the cerebellum communicate with the rest of the CNS?
through 3 bundles of neural tracts called cerebellar peduncles
What are the 3 peduncles of the cerebellum called?
Inferior peduncles (receives sensory info, monitors timing & force of movement)
Middle peduncles (receive & coordinates preliminary info from cortex regarding planned movements)
Superior peduncles( main output channel to CNS)
What is the most important function of the cerebellum?
Coordination of rapid alternating movements, body balance during movement and motor programming (timing) & maintenance of muscle tone.
The cerebellum is _______ innervation.
double crossing
this means symptoms are ipsilateral
What is the brainstem divided into?
- midbrain
- pons
- medulla
What originates in the brainstem?
the cranial nerves
Why is the brainstem important?
acts as a passageway for descending and ascending neural tracts;
controls respiration and consciousness;
conveys motor impulses from CNS to muscles of larynx, face, tongue, pharynx and velum
There are ___ sensory only CNs, ___ motor only CNs and ___ mixed CNs.
3
5
4
How many CNs are important for speech and swallowing?
5 to 6 CNs
The innervation of CNs to muscles is _______.
ipsilateral
CN V (Trigeminal)
jaw open and close
CN VII (Facial)
muscles of lips, cheeks, facial expressions
CN IX (Glossopharyngeal)
elevates pharynx, gag reflex
CN X (Vagus)
larynx pharynx, soft palate muscles; recurrent laryngeal branch and superior laryngeal branch
CN XI (Accessory)
motor to pharynx, larynx, soft palate and neck; supports CN X
CN XII (hypoglossal)
muscles of the tongue
What CNs are most relevant to speech functions?
CNs V, VII, IX, X, XI, and XII
Most CNs recieve innervation bilaterally from cerebral cortex, except CN ___ and CN ___.
VII; XII
Why do spinal nerves play an important role in speech production?
Spinal nerves are important for breathing functions in relation to swallowing and phonating
What levels of the nervous system does the speech motor system involve?
CNS, PNS, control circuites and descending motor pathways
Motor planning =
structure specific
Motor programming =
muscle specific
Motor execution =
primary motor cortex
Upper motor neurons originate in the ______ and terminate on _____.
cortex; LMN
T or F? All UMNs cross over to the opposite side before synapsing on LMNs.
True
Where do LMNs originate; terminate?
originate= in spinal cord or lower level of brainstem in PNS terminate = on muscles they innervate
LMN system =
final common pathway
UMNs cross over at ?
Pons or medulla level
T or F?
UMN: Neuron cell bodies are not found within the CNS.
False;
all neuron cell bodies are in CNS.
UMN system tracts are termed ______ and ______.
direct and indirect activation pathways.
certain muscles are continuously contracted; leads to weak/slow movements and reduced range of motion
Muscle spasticity
abnormally increased muscle tone
hypertonia
exaggerated muscle’s stretch reflex; indication of UMN disease
hyperreflexia
muscular spasm involving repeated, often rythmic contractions
clonus
signs of UMN damage includes…
muscle spasticity, hypertonia, hyperreflexia, and clonus
LMN system: neuron cell bodies are found where?
in cranial/spinal nerves (PNS)
reduced muscle tone; results in paralysis/paresis/weakness
hypotonia
loss of muscle bulk due to lack of innervation (only seen MSD associated with LMN)
atrophy
involuntary muscle contractions (visible to eye)
fasciculations
involuntary contraction of individual muscles (not visible)
fibrilliations
signs of LMN damage includes…
hypotonia, atrophy, fasiculations, and fibrilliations
direct activation pathway AKA pyramidal system
system for voluntary motor control for face and body
indirect activation pathway AKA extrapyramidal system
mostly involuntary/automatic control
Function of Pyramidal system
pathways are faciltory for skilled, discrete movements; very important for speech
corticobulbar tract : supplies musculature of ______ :: cortispinal tract : supplies musculature of _____.
head/face and neck
limbs
Corticobulbar tract: comprised, originates, crosses, & synapses?
comprised: of UMN
originates: in primary motor cortex
crosses: to opposite side of brain at brainstem
synapse: on cranial nerve nuclei at various levels of brainstem
Corticobulbar projection to most cranial nerve nuclei is bilateral, but is contralateral to CN ____ and ____.
CN VII and CN XII.
Function of Extrapyramidal System
helps regulate reflexes and maintain posture, tone and associated activities that provide framework for skilled movements; many inhibitory movements
Speech Motor System
higher cognitive center (intent) –> association areas (motor plans) –> association areas + control circuits (programming)
–> primary motor cortex
Corticospinal tracts: _____ UMN input to spinal nerve.
contralateral
corticobulbra tracts: _____ UMN input to most crabial nerves (except CNs VII and XII)
bilateral
LMN system = _____ innervation
ipsilateral
Which cranial nerve has 3 branches?
CN V
Unilateral LMN damage to CN V symptoms
- jaw deviates to weak side when opened
- mildly reduced strength of masticator muscles on same side as lesion
- no major effects on speech
Bilateral LMN damage to CN V symptoms
- jaw hangs open & cant be closed; slow or limited range
- reduced strength of masticator muscles on both sides
- artic affected in major way
Unilateral UMN damage to CN V sympotoms
No real affect on speech; other side will accommodate
Bilateral UMN damage to CN V symptoms
- limited jaw movement
- mandible hangs low; exaggerated jaw jerk
- artic affected in major way
CN VII innervates ____ of the face bilaterally and _____ of the face contralaterally.
upper 1/3
lower 2/3
Unilateral LMN damage to CN VII
- entire side of face ipsilateral to lesion droops
- no wrinkles, difficult to close eye, corner of mouth droops, flattened nasolabial fold
- atrophy of muscles on side of face ipsilateral lesion
- speech is not negatively affected to great extent
Bilateral LMN damage to CN VII
- paralysis on upper and lower facial muscles on both sides of face
- (may) preserve emotional expression (laugh)
- hearing is affected bilaterally
- major difficulty producing labial and labiodental sounds
Unilateral UMN damage to CN VII
- lower 2/3 of face on contralateral side of lesion will be affected
- flatted nasolabial fold
- corner of mouth drops
- little effect on speech
Bilateral UMN damage to CN VII
- both sides of face affected
- (may) preserve emotional expression (laugh)
- hearing is affected bilaterally
- major difficulty producing labial and labiodental sounds
Unilateral LMN damage to CN X
- palate droops on ipsilateral side to lesion
- mild hypernasality
- VF paralyzed on same side as lesion
- breathy
- dipholphonia
- weak pharynx on same side as lesion
- swallowing difficulty
Bilateral LMN damange to CN X
- serious life risks b/c airway compromised
- palate droops bilaterally
- severe hypernasality
- bilateral VF paralysis
- severe breathiness
- inhilation stridor
- severe swallowing difficulty
Unilateral UMN damage to CN X
- minimal to no effect on phonation, resonance or swallowing
- harsh voice quality
Bilateral UMN damage to CN X
- paresis of VFs
- spasticity of VFs
- strained-strangled phonation
- hypernasality
- swallowing difficulty
Unilateral LMN damage to CN XII
- atrophy, weakness and fasciculations of the tongue on same side as lesion
- tongue deviates to side of lesion (weak side) on protrusion
- mild imprecise artic
- may have difficulty moving food around mouth
Bilateral LMN damage to CN XII
- bilateral atrophy, weakness and fasciculations of tongue
- tongue protrusion may be limited/nonexistant
- no tongue deviation
- mild-severe imprecise artic
- severe difficulty swallowing and eating
Unilateral UMN damage to CN XII
- some weakness of tongue on opposite side of lesion
- tongue deviates to side opposite of lesion on protrusion
- mild imprecise artic
bilateral UMN damage to CN XII
- bilateral tongue weakness
- no tongue deviation
- tongue protrusion may be limited/nonexistant
- mild-severe artic imprecisio n
- severe difficulty in swallowing and eating
