SPLH 620 Exam 3
What two motor neurons does the CNS possess? - ANS-1. UMN (cerebrum)
2. LMN (brainstem, spinal cord)
What is Dysarthria? - ANS-poor movement of the vocal tract
What is Ataxia? - ANS-poorly coordinated movements
What is Apraxia of speech? - ANS-errors in planning speech
movements
What are the three most important motor cortical areas? - ANS-1. Primary motor
2. Premotor
3. Supplementary motor
What is the pathway of the Spinal Motor Pathway? - ANS-—Upper motor neurons
1. Cerebral cortex to spinal cord
2. Descend through the internal
capsule
3. Decussates in medulla
(brainstem)
4. Synapse in anterior horn of
spinal cord: Corticospinal tract
5. Does not go through thalamus
—Lower motor neurons
6. Cell body in anterior horn of SC
7. Synapse with muscle fibers =
Motor Unit
What is the internal capsule? - ANS-It contains collections of axons that belong to both
spinal motor pathway and some ascending pathways (containing descending and
ascending)
What is the pathway of the bulbar motor pathway? - ANS-• Upper motor neurons
1. Cerebral cortex to
Brainstem
2. Descend through the
,internal capsule
3. Synapse on Cranial Nerve
Nuclei: Corticobulbar tract
4. Does not go through
thalamus
• Lower motor neurons
5. Cell body in cranial nerve
nuclei
6. Synapse with muscle fibers
= Motor Unit
What are the brainstem's 3 functions? - ANS-1. Functions as a conduit: corticospinal
tract, DCML & ALS
2. Cranial nerve function: Spinal cord-like function for the head
3. Integrates information: reticular information, complex motor patterns
What are the 3 parts/areas in the brainstem? - ANS-1. Midbrain
2. Pons
3. Medulla
What is the reticular formation involved in? - ANS-1. Control of movement
2. Modulating transmission of info in
pain pathways
3. Autonomic reflex circuitry: breathing,
heart rate, blood pressure
4. Control of arousal and consciousness
How exactly does brainstem integration work? - ANS-The central pattern generator
(which is enabled by the working of the reticular formation). The reticular formation
makes rhythmic behavioral patterns by integrating motor and sensory info by having the
excitatory and inhibitory neurons work together (i.e. when one neuron is firing the other
one isn't). loose interconnected neuron in BS responsible for integrating motor and
sensory info to make such rhythmic patterns
What do the dorsal and ventral rootlets of the spinal cord control? - ANS-Dorsal:
sensory
Ventral: motor
(These merge to form the spinal cord)
, What is the difference between the spinal cords horns and its funiculi? - ANS-Horns are
the grey matter structure (butterfly like), Funiculi is the white matter surrounding it
Spinal injury examples study!! - ANS-STUDY
What is the definition of reflex and what does it involve? - ANS-1. Involuntary
stereotyped response to sensory input
2. Sensory neuron, Motor neuron, and (Interneuron)
What are motor units? - ANS-Motor unit: motor neuron + muscle fiber
• Motor neuron "activates" with action potential and releases acetylcholine (ACh)
• ACh is an excitatory neurotransmitter of the PNS
Each X innervates a fraction of the muscle
fibers in one muscle. The combination of and all the muscle fibers it innervates is a Y. -
ANS-1. lower motor neuron
2. motor unit
What are small vs. large motor units in charge of? Also how does motor unit recruitment
work? - ANS-1. - Small: fine control, low force - Large: gross control, high force
2. Smallest to largest according to needs
• Managed by the CNS
Increasing X firing frequency recruits
motor units in order of their strength.
• Muscle contraction strength is therefore controlled by Y. - ANS-X = UMN
Y = the number and rate of neurons firing
What do 1) somatic 2) special and 3) visceral motor all innervate? - ANS-1. Innervate
skeletal muscle
2. - Innervates "special" branchiomeric skeletal muscles
3. Innervates (smooth) visceral muscle
FIND OUT WHAT CN EACH FALLS INTO!
What are the motor branchial cranial nerves ? - ANS-V, VII, IX, X, XI
What is the pathway of motor for the body? - ANS-- UMN
• Corticospinal tract
1. From Motor cortex (frontal lobe)
2. Pyramidal decussation
What two motor neurons does the CNS possess? - ANS-1. UMN (cerebrum)
2. LMN (brainstem, spinal cord)
What is Dysarthria? - ANS-poor movement of the vocal tract
What is Ataxia? - ANS-poorly coordinated movements
What is Apraxia of speech? - ANS-errors in planning speech
movements
What are the three most important motor cortical areas? - ANS-1. Primary motor
2. Premotor
3. Supplementary motor
What is the pathway of the Spinal Motor Pathway? - ANS-—Upper motor neurons
1. Cerebral cortex to spinal cord
2. Descend through the internal
capsule
3. Decussates in medulla
(brainstem)
4. Synapse in anterior horn of
spinal cord: Corticospinal tract
5. Does not go through thalamus
—Lower motor neurons
6. Cell body in anterior horn of SC
7. Synapse with muscle fibers =
Motor Unit
What is the internal capsule? - ANS-It contains collections of axons that belong to both
spinal motor pathway and some ascending pathways (containing descending and
ascending)
What is the pathway of the bulbar motor pathway? - ANS-• Upper motor neurons
1. Cerebral cortex to
Brainstem
2. Descend through the
,internal capsule
3. Synapse on Cranial Nerve
Nuclei: Corticobulbar tract
4. Does not go through
thalamus
• Lower motor neurons
5. Cell body in cranial nerve
nuclei
6. Synapse with muscle fibers
= Motor Unit
What are the brainstem's 3 functions? - ANS-1. Functions as a conduit: corticospinal
tract, DCML & ALS
2. Cranial nerve function: Spinal cord-like function for the head
3. Integrates information: reticular information, complex motor patterns
What are the 3 parts/areas in the brainstem? - ANS-1. Midbrain
2. Pons
3. Medulla
What is the reticular formation involved in? - ANS-1. Control of movement
2. Modulating transmission of info in
pain pathways
3. Autonomic reflex circuitry: breathing,
heart rate, blood pressure
4. Control of arousal and consciousness
How exactly does brainstem integration work? - ANS-The central pattern generator
(which is enabled by the working of the reticular formation). The reticular formation
makes rhythmic behavioral patterns by integrating motor and sensory info by having the
excitatory and inhibitory neurons work together (i.e. when one neuron is firing the other
one isn't). loose interconnected neuron in BS responsible for integrating motor and
sensory info to make such rhythmic patterns
What do the dorsal and ventral rootlets of the spinal cord control? - ANS-Dorsal:
sensory
Ventral: motor
(These merge to form the spinal cord)
, What is the difference between the spinal cords horns and its funiculi? - ANS-Horns are
the grey matter structure (butterfly like), Funiculi is the white matter surrounding it
Spinal injury examples study!! - ANS-STUDY
What is the definition of reflex and what does it involve? - ANS-1. Involuntary
stereotyped response to sensory input
2. Sensory neuron, Motor neuron, and (Interneuron)
What are motor units? - ANS-Motor unit: motor neuron + muscle fiber
• Motor neuron "activates" with action potential and releases acetylcholine (ACh)
• ACh is an excitatory neurotransmitter of the PNS
Each X innervates a fraction of the muscle
fibers in one muscle. The combination of and all the muscle fibers it innervates is a Y. -
ANS-1. lower motor neuron
2. motor unit
What are small vs. large motor units in charge of? Also how does motor unit recruitment
work? - ANS-1. - Small: fine control, low force - Large: gross control, high force
2. Smallest to largest according to needs
• Managed by the CNS
Increasing X firing frequency recruits
motor units in order of their strength.
• Muscle contraction strength is therefore controlled by Y. - ANS-X = UMN
Y = the number and rate of neurons firing
What do 1) somatic 2) special and 3) visceral motor all innervate? - ANS-1. Innervate
skeletal muscle
2. - Innervates "special" branchiomeric skeletal muscles
3. Innervates (smooth) visceral muscle
FIND OUT WHAT CN EACH FALLS INTO!
What are the motor branchial cranial nerves ? - ANS-V, VII, IX, X, XI
What is the pathway of motor for the body? - ANS-- UMN
• Corticospinal tract
1. From Motor cortex (frontal lobe)
2. Pyramidal decussation
