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Physiology exam 2- Motor Nervous system
Terms in this set (242)
Motor _________ serve essential needs (locomotion, posture, breathing).
Motor programs range from _______ actions (withdrawl reflexes) to complex ___________ activities.
Motor control depends on ______________ signals (stretch receptors) and _________ activity (spinal cord)
sensory signals, reflex activity
Higher ______________ (brain) superimpose commands (____________) on spinal cord reflexes
motor centers, motor programs
Motor __________ superimpose motor __________ on the spinal cord
What makes up a motor unit?
The motor neuron and the muscle fiber(s) it innervates.
The _________ is the basic element in motor control.
The ______________ is the final common pathway by which the CNS causes muscle contraction.
alpha motor neuron
The alpha motor neuron is an ___________________ only pathway.
Skeletal muscles =
The regulation of the saccades in the eye are an example of ___________ movement control over skeletal muscles.
Skeletal muscle itself has __________ in it and is part of a ________ loop.
receptors, reflex loop
The skeletal muscle is the __________ of the reflex loop.
The alpha motor neuron is an _____________. If you ose the alpha motor neuron, the muscle won't contract.
The alpha motor neuron is efferent and ___________ only.
The alpha motor neuron is governed by the _________ nervous system.
One alpha motor neuron can control ____ to more than ______ muscle fibers (cells) and all will be in the same ___________.
a motor neuron and all of the muscle fibers it controls = __________
A small motor unit has few fibers (3-10) and these motor units are for _________________.
A large motor unit has more fibers (up to or more than 1,000) and is for ______________
The skeletal muscle is the _________ nervous system
The ________ of the motor unit is sitting in the spinal cord. It sends its axon out through the ________ root.
A motor neuron can innervate more than one ___________
Some muscles have few fibers. Some have many. Regardless of the number of fibers, the alpha motor neuron plus all of the fibers it controls is one ____________.
Motor reflexes (ex- lifting finger from hot stove) occur at the level of the _____________.
Motor reflexes occurring at the spinal cord are independent of the ________.
In a motor reflex, the alpha delta pain fiber comes into the dorsal horn and we have ___________ (where a lateral signal is sent over to the alpha motor neuron in the ventral horn).
In the motor reflex, the sensory input (alpha delta pain fiber) enters the _______ root of the cord. It synapses with an interneuron, which activates the ______________, which exits the ________ horn to activate the skeletal muscle.
dorsal, apha motor neuron ventral
most skeletal muscles move the _________ (with the exception of muscles like the esophagus, muscles of lips, and middle ear).
Skeletal muscle often inserts just behind a __________.
Skeletal muscle just beyond a joint is important for _______ action, where small degrees of ______ cause large movements.
There is usually skeletal muscles on either side of a joint. One is a ___________ and one is an __________.
__________ close the angle of a joint
__________ open the angle of a joint
Flexors and extensors are ___________ pairs of muscles.
What does it mean to say that flexors and extensors are antagonistic pairs of muscles?
When I am contracting a flexor, I am relaxing the extensor. Antagonistic movement in relation to one another.
Antagonistic pairs of muscle have ___________ innervation.
If we have __________ innervation from the spinal cord, its close to the midline.
Muscles that control posture are coming out of the spinal cord near the __________ of the ventral horn.
Muscles that are distal, away from the midline, like the hands and forearms, are innervated by fibers that are located more _______ within the ventral horn of the spinal cord.
laterally (away from the midline). They are in the outer portion of the ventral horn.
Three levels of complexity/control occur in the motor control ______________.
The __________ is the lowest level of control, and controls reflex coordination.
To have postural control, we need more than just the spinal cord. To add these kinds of complications to our movement/motion, we need the ____________.
The ___________ is our highest level of motor control, and is involved in planning, initiating and directing voluntary movements.
In motor neuron pathology, we have a problem with our _______________.
alpha motor neuron.
In upper motor diseases are diseases that are affecting the _____________.
input from the cortex (the higher order)
What is misleading about the phrase "upper motor neuron pathology?"
There are no actual alpha motor neurons up in the cortex. This is not a true disease of the alpha motor neuron, rather, they are diseases in which the input from the cortex TO the alpha motor neuron is affected.
Motor neurons located in the medial part of the ventral horn of the spinal cord (cervical and lumbar) govern ___________.
Motor neurons located in the lateral ventral horn govern _____________ of forearm, hand, and (most lateral) fingers, extensors and flexors.
fine skilled behavior
Motor neurons in the medial ventral horn of the spinal cord govern postural control and receive input from _________________ and _______________.
upper motor neurons, local interneurons
Interneurons of the medial region of the spinal cord project __________.
Motor input exits from the ____________ horn.
Alpha motor neurons innervate __________ muscle fibers.
Alpha motor neurons innervate extrafusal muscle fibers to _____________ for posture and movement.
Gamma motor neurons innervate __________ muscle fibers (muscle spindle)
Intrafusal muscle fibers are also known as the _________-
The muscle spindle shortens concurrent with the shortening of the ________________ muscle fibers.
Why does the muscle spindle shorten concurrent with the shortening of the extrafusal muscle fibers?
It enable the muscle spindle to correctly "sense" the fiber's length and stretch.
ALpha and gamma motor neurons are ___________ fibers.
During muscle contraction, the alpha and gamma motor neurons are ____________.
Alpha motor neurons activate the extrafusal muscle fibers to generate force for posture and movement. This gives us ________.
When gamma motor neurons innervate the intrafusal muscle fibers (muscle spindle), does this generate tension?
When gamma motor neurons innervate the intrafusal muscle fibers, it enables the muscle spindle to correctly sense how far we've ___________ the fiber, and how long it is when stretched.
gamma motor neurons allow the __________ muscle fibers to prevent damage from overstretching.
The muscle spindle (intrafusal muscle fibers) do not relay information about how quickly the muscle _________, only relays info about __________.
The muscle spindle is a _________________ that reports stretch (muscle length and speed of stretch)
The muscle spindle is ___________ and sends info through the __________ horn.
sensory, dorsal horn.
What information does the muscle spindle relay?
How long the muscle is, that it's being stretched, and the speed of the stretch.
What info does the muscle spindle NOT relay?
Info about relaxation.
What is the importance of the muscle spindle?
If a muscle is being stretched, the spindle sends info to the spinal cord via the dorsal horn. The spinal cord has the muscle contract to oppose the stretching activity, to bring the muscle back to its original state.
Activation of the muscle spindle leads to ___________ of the stretched muscle and concurrent __________ of the antagonistic muscle.
Activation of the spindle leads to contraction of the stretched muscle and concurrent relaxation of the antagonistic muscle by _______________.
reciprocal innervation (reciprocal inhibition)
The spindle is __________ muscle fibers innervated by _____________ neurons.
intrafusal, gamma motor neurons
When the spindle is stretched, the ___________ fiber informs the spinal cord of the change.
a1 sensory fiber
In the muscle stretch reflex, the ___________ sensory fiber from the spindle sends info into the dorsal horn and we have __________. This ___________ the alpha motor neuron to the extensor (to contract) but also _____________ the alpha motor neuron to the flexor (to relax). The ____________ neuron is coactivated to the hamstrings to maintain length of the spindle.
1a, divergence, activates, inhibits, gamma motor
Antagonistic muscle pairs have ___________ innvervation, as well.
The _______________ is encapsulated afferent nerve endings located in the tendon, which are in series with the extrafusal muscle fibers.
golgi tendon organ.
The golgi tendon organ is encapsulated __________ nerve endings located in the tendon which are in series with ________ muscle fibers.
The golgi tendon organ is activated by ___________ of the muscle and not by ____________.
The afferent sensory signal from the Golgi tendon organ is sent to the spinal cord by the ___________ sensory neuron.
The golgi tendon organ is a second _______________, sitting at the tendon. (Muscle itself attaches to the bone through the tendon).
When a muscle starts to contract, it is very ____________. It puts a lot of _________ on the tendon when it pulls. Tendon is made out of __________ tissue and is not very elastic.
powerful, force/tension, connective
The little sensor that is the Golgi tendon organ is telling the body how much ________ is being developed by the muscle.
What does the body do in response to the Golgi tendon organ sending afferent signal about the tension being created by muscles?
It responds by counteracting the tension that the muscle is causing. The alpha motor neuron will send a signal to inhibit, which will counteract the tension.
The 1b fiber is a __________ neuron.
In the withdrawal reflex, ____________ mediates withdrawal of a limb from a painful sensory stimulus.
Reflex circuitry, which is also known as __________, is what mediates the withdrawal of a limbfrom a painful sensory stimulus (ie- stepping on a sharp shell on the beach_
In the withdrawal reflex, on the __________ side to the injury, the flexor is activated, and the __________ is inhibited.
ipsilateral, extensor inhibited
In the withdrawal reflex, the extensor is activated and the flexor is inhbited on the _____________ side to the injury.
During the withdrawal reflex, we are sending information to the side that opposes the injury, too. This provides postural support during the withdrawal of the affected limb, and is called the _________________.
crossed extensor reflex.
The crossed extensor reflex provides ___________ support during withdrawl of the affected limb during the withdrawal reflex.
Pain input to the spinal cord excites/inhibits reciprocal muscles on the injured side of the body causing ____________ relfex, and on the opposite side of the body to _____________.
withdrawl reflex, to support body weight.
We can use the ___________ reflex to walk.
Locomotion uses _________ innervation and ________ reflex.
reciprocal innervation, withdrawal reflex.
Reciprocal swing phase of a limb (________ flex) and stance phase (__________ extension) is used in walking.
forward flex,backward extension
Locomotion, and the swing and stance phases are a __________ spinal reflex.
repeated spinal reflex.
In ________ innervation, the contralateral side is doing the opposite of the first side.
What are the two parts to the locomotion of walking?
stance and swing
In ________, the ankle is unloaded. This is the signal to shift weight to the opposite side and contract the _________.
In the stance phase of locomotion of walking, the unloading of the ankle is the _________ to the reflex loop.
The sensory input from unloading the ankle tells the body to contract the ____________ on the opposite side, and contract the _____ on the ipsilateral side.
The _________ reflex is the reflex loop.
The stance and swing are controlled by the ___________. The postural support in walking comes from the ___________.
spinal cord, brain stem
The withdrawal reflex only needs the spinal cord, but to walk we still need a _________ support element.
In lower motor neuron syndrome, we have ________- there is damage to the spinal cord and we lose the ___________ neuron.
pathology, alpha motor
When we lose the alpha motor neuron, there is no ___________ to the skeletal muscle
Lower motor neuron pathology is characterized by:
1. Damage to the __________ of the spinal cord.
2. _________ paralysis (loss of movement) or _________ (weakness) of the affected muscles
3. _________ reflexes
3. Loss of ___________ (i.e., resistance to stretch), and later, ________ of the affected muscle.
1. Alpha motor neuron
2. flaccid paralysis, paresis
4. muscle tone, atrophy
Why is there atrophy of muscle with lower motor neuron syndrome and hypotonia?
Loss of the alpha motor neuron means loss of the growth factor that it secretes. As a result, the muscle will atrophy.
___________ is unique to lower motor neuron pathology. It does not happen with upper neuron pathology/disease.
Loss of muscle tone means decreased resistance to __________ .
Spinal Central Pattern Generators occur independent of _______________ input
___________________: neural circuits that produce timing and coordination of movement independent of sensory input.
spinal central pattern generators (CPG).
____________ is a CPG. It happens rhythmically, but there is nothing "telling us" to do it.
Breathing, a CPG, is happening due to input from the _____________.
The respiratory control center is in the __________, setting timing for breathing. (a CPG)
Spinal central pattern generators (CPG) are characterized by being ___________ and ___________.
Oscillatory and flexible.
Our normal walking is ____________...we have a swing and a stance phase, and that's at the level of the spinal cord.
Central pattern generators can be at the level of the ___________ (walking) or at the level of the ____________ (breathing)
spinal cord, brain stem
Central pattern generators are ____________ - you can change from walking to running by decreasing stance phase and sequence of limb movements in quadrapeds).
flexible. (walking to running, change of speed)
What does the brain stem CPG allow to happen with walking, that makes it above and beyond the control of the spinal cord?
Regular walking is done at the level of the spinal cord BUT if you want to walk backwards, you need the brain stem. Brain stem can change the patterns of the movement.
The brain stem can change the ____________ of the movement within the CPG.
In reference to CPG, if I want to run, I need the __________. If I want to skip, I need the _____________.
spinal cord, brain stem
The brain stem can adjust the CPG response to ___________ feedback (smoothing the gait). (Ex- the brain stem coordinates CPG governing the limbs to walk forward OR backward)
When the brain stem adjusts the CPG response to sensory feedback by smoothing the gait, this is ____________ control.
The second level in the hierarchy of control is ___________ control
The brainstem is getting information from the __________, to smooth out the gait.
When the brain stem gets information from the cerebellum to smooth the gait, it is getting _____________ control. The brain stem is giving us _________ control.
We get information into the brain stem through our _________, our ________ system, and the ____________. All this information is coming in and we control our movements from this information.
eyes, vestibular system, cerebellum
Feed forward control is from the ____________.
The ____________ gives us postural control (stand upright against gravity)
feed-forward control controls the limbs and corrects for postural stability. This feedback is a _________ thing. The cerebellum learns to correct! (ex- you fall on your face while learning to walk, but eventually, the cerebellum learns how to do it better.
The cerebellum learns how to control __________ and to control the body system.
The cerebellum learns how to control the body systems and timing. This is all done through the brain stem _____________.
Brain stem motor centers control Spinal CPG without input from __________________.
the motor cortex
Brainstem motor programs serve __________ needs. (breathing, swallowing)
The brain stem mediates __________ and _________ control of posture.
Feed-forward is _____________ and typically ________ the onset of movement.
Feed-back is initiated by sensory inputs that detect __________.
The brainstem pathway starts in the brainstem and will control in an _____________ manner.
The brain stem pathway acting in an ipsilateral manner gives us postural and ________ control.
The brainstem pathway acts as the feed forward for __________ and ____________.
muscle tone and postural adjustments
The brainstem pathway acts as the feed forward for muscle tone and postural adjustements. Then, we can control the opposite side. This is the _________ reflex.
The __________ pathway generates rhythmic CPG and controls ipsilateral postural and proximal limb muscle activity.
The __________ tract controls facial muscles movement of the head face and neck.
What does the corticobulbar tract control?
ipsilateral movement of head face and neck, and bilateral control of facial muscles.
The corticobulbar tract is mostly ipsilateral movement/control, but it also has control of the facial muscles, which is ________ control.
What kind of control does the cortiobulbar tract have over facial muscles?
The corticobulbar tract terminates in the _____________.
The corticospinal tract is also known as the __________ tract.
The corticospinal tract starts in the ______________ in the ________ lobe, adjacent to the _________.
cortex, frontal, parietal
The corticospinal tract sends information starting in the ___________ and descending to the ___________.
frontal lobe, medulla.
In the corticospinal tract, _________% of the information crosses the midline in the medulla.
The 80% of information from the corticospinal tract that crosses the midline in the medulla controls the motor activity of contralateral ______________ and ________.
distal limbs and digits
In the corticospinal tract, we are controlling motor programs in the _________ side by having the information cross the midline at the medulla.
In the corticospinal tract, _________- of the information descends to the spinal cord, where the control will be initiated, and then it crosses the midline.
In the corticospinal tract, the 20% of information that crosses midline in the spinal cord is for ____________ control.
What is the highest level of control for motor programs?
The information descending from the corticospinal tract will always ___________________, just in different locations, which is why it controls contralateral motor activity.
cross the midline
The __________ tract coordinates complex motor programs.
Information from the corticospinal tract comes from the ___________ in the frontal lobe.
primary motor cortex.
The corticospinal tract sends its information from the primary motor cortex in the frontal lobe via ____________ fibers, which descend.
80% of the information from the corticospinal tract descends from the cortex, crosses the midline at the medulla, and then descends in the _______________ of the spinal cord. These are _________ in the _________ horn.
lateral white matter, lateral, ventral
The 80% of information from the corticospinal tract that descends in the lateral white matter gives us __________ movement of our hands, fingers, forearms, etc.
The other 20% of information in the corticospinal tract that descends from the cortex crosses the midline at the level of _______. This information goes to the _______ region of the _____ horn of the spinal cord.
control, middle, ventral
It is important to remember that information coming down the corticospinal tract is just ____________ coming down from the frontal lobe. There are no actual __________ up in the cortex!
motor programs, motor neurons
The descending tracts of the corticospinal tract are ___________ tracts.
The descending tracts that are coming down from the brain are inhibiting the amount of _________ that goes out to the muscles
The alpha motor neuron synapse at the muscles is always ________, and sometimes it gets too much excitation. So the descending pathways coming down from the brain are modulating that.
Inhibition of the amount of excitation that happens at the alpha motor neuron synapse with skeletal muscle is dampened by the ______________ via descending pathways of the corticospinal tract. This is ________ input which dampens the amount of excitations to the muscle.
upper motor neuron control, negative input
The ____________ of the frontal lobe plans and initiates motor programs.
primary motor area
_____________ movement is initiated in the cortex.
The Motor cortex in the frontal lobe has a ___________ (map)
The homunculus of the motor cortex is ________ and less ________ than the one in the parietal lobe for the somatosensory cortex.
smaller, less well-defined
Why is the map of the motor cortex smaller and less well defined than that of the somatosensory cortex?
We don't have robotic movement. We have more flexibility in the motor program- there are several different ways to execute a motor program, the purpose of this map is to choose the way that allows optimal task performance.
Because we have so many choices in the motor cortex, the homunculus is more __________ than that of the somatosensory cortex.
Because the information sent down from the cortex always crosses the midline, the motor cortex homonculus represents _________- control. Therefore, there is a homunculous in both the ___________ and ________.
contralateral, right hemisphere and left hemisphere.
The __________ motor units have the largest motor area in the map of the motor cortex.
The motor units that have the largest motor area in the map of the motor cortex sit __________ on the map.
Why do the smallest motor units take up the largest motor area iand sit laterally n the map for the motor cortex?
The smallest motor units are the areas where we have the largest amount of fine motor control (and not a lot of force).
The larger motor units that give us more force, but less fine motor control, sit ____________ on the map of the motor cortex.
medially (ex- the legs)
The primary motor area (frontal lobe) plans and initiates __________.
The primary motor area (frontal lobe) initiates motor programs and is regulated by the __________-- and ____________ via the _________ and sensory input from the _________-lobe
basal ganglia, cerebellum thalamus, parietal
The objective of the homonculus of the motor cortex is _____________ and not stereotypical movement patterns, like in the somatosensory cortex. So, this map depicts __________ and not specific ___________.
optimal task performance, movements, specific muscles
There is _________ within the cortexes. (the motor programs have more than the somatosensory, though, because of how many different ways we can perform a task).
The brain controls whatever tools you give it....these tools don't have to be _________________. (ex- monkey playing video games with robotic arm)
attached to the body
In situations of upper motor neuron syndromes, there are no _________ in the cortex! Remember, the pathology here is damage to the ___________ or the _________!
alpha motor neurons, corticospinal tract , primary cortex (the signal being sent down to the alpha motor neuron is what's being affected).
Why do you get weakness to the muscle with upper motor neuron pathology?
The signal being sent to the alpha motor neuron is altered.
___________ issues in upper motor neuron pathology are a result of ________ muscle tone, __________ stretch reflexes, and ________ in response to stretch.
Spasticity, increased, hyperactive, spasms
In upper motor neuron pathology, you see _________ of fine, independent (voluntary) motor movement. (ex-fingers)
One of the biggest differences between upper motor neuron pathology and lower motor neuron pathology is that in upper motor neuron pathology, there is no _____________ of the muscles.
Why is there no muscle atrophy with upper motor neuron diseases/pathology?
The innervation for the alpha motor neuron is still present, and it is the alpha motor neuron that secretes growth factor. Therefore, growth factor is still secreted.
In upper motor neuron diseases/pathology, we haven't damaged the spinal cord alpha motor neurons, we have damaged the __________ thats coming down the descending tracts from the cortex.
What are the four main ways to characterize upper motor neuron syndromes/pathology?
1. Damage to corticospinal tracts and/or primary cortex
4. Loss of fine voluntary movement (ex- loss of independent movement of fingers.
Loss of independent movement of the fingers is classified as loss of ____________ movement, and is characteristic of ___________ pathologies.
fine voluntary movement, upper motor neuron
The basal ganglia select which ___________ in the brain stem and spinal cord is initiated.
How do the basal ganglia select which motor program in the brain stem and spinal cord is initiated?
They regulate tonic inhibition of the thalamus.
Basal ganglia reguate __________ inhibition of the thalamus.
The __________ is a relay point that governs how much inhibition is going to be delivered to the spinal cord, but this is regulated by the basal ganglion.
The thalamus is a relay point for ________ coming down from the brain to the spinal cord.
In the case of Parkinson's disease, we have a problem with the _________ of the brain.
In the case of Parkinsons, the loss of ________-- from the basal ganglia (subst. Nigra) to the striatum _________ inhibition of the thalamus by Substantia Nigra, and Globus Pallidus, resulting in ___________.
dopamine, increases, hypokinesis
In parkinson's, dopamine is the ________. If we lose that (have a loss of dopamine we get a lot of inhibition of GABA going into the __________. They have what's called _________ Parkinson's-- they have problems starting and stopping walking.
brake, thalamus, frozen parkinsons
Spinal cord stimulation for dopamine/frozen parkinsons worked in the _______ and the __________ but not in humans.
Frozen parkinsons is a situation where we have too much ____________ coming down from the thalamus.
Loss of dopamine from ___________ (Subst. Nigra) to the __________ increases inhibition of the thalamus by ____________ and _________ resulting in hypokinesis.
basal ganglia, striatum, Substantia Nigra, Globus Palladius
The opposite of Frozen Parkinson's-- when we don't have _________ inhibition, the control of the limbs is affected.
What happens to the limbs without sufficient inhibition from the thalamus?
Hyperkinetic disorder- excessive and abnormal movement (writhing,tremor at rest)
____________ disorder: excessive and abnormal movement (writhing, tremor at rest)
In hyperkinetic disorder, _______________ of the thalamus is altered, resulting in increased excitatory outflow to motor neurons by the thalamus.
In Huntington's disease, there is a problem with the amount of GABA- the thalalmus has in increase of _________ outflow. This means there is not ____________ to allow controlled movement!
excitatory, enough inhibition
____________ disorder: absence of movement (resting tremor, akinesia, muscle rigitity)
In hypokinetic disorder, tonic inhibition of the thalamus is altered due to _____________- in the substantia nigra, resulting in __________ excitatory outflow to motor neurons by the thalamus. (ex frozen parkinsons)
loss of neurons, descreased excitatory outflow
In hypokinetic disorder, there is ____________ inhibition coming from the thalamus to allow movement. ( a person cant start or stop moving)
too much inhibition
The _________ modifies upper neuron activity to provide smooth, well-coordinated movements. (________-forward)
The cerebellum detects _________ between intended and actual movement and _________ this error.
motor error, corrects
How does the cerebellum correct motor error?
The cerebellum influences upper motor neuron output to antagonistic skeletal muscles! (flexor vs extensor, etc).
In the cerebellum, corrections can be made during a movement or as ____________ when the correction is being stored (motor memory)
When the cerebellum allows corections to be made during motor movement due to motor memory, this is called _________ control.
Damage to the _________ causes persistent errors in executing movement.
Cerebellar _______: jerky, imprecise movements
When there are errors in executing movement as a result to cerebellar damage, these movement areas are always on the _________ side of the body as the damage to the cerebellum.
The cerebellum does not _______ movement. It __________ coordinated movement.
An individual who has a problem with the cerebellum presents with _________ (jerky imprecise movements) and _______- gait.
ataxia, wide gait.
Damage to the cerebellum affects the __________ of the movement of the limbs.
What happens without the feed-forward control of the cerebellum?
There are intentional tremors, because a person cannot smoothly target the muscles needed to pick an item up, for example.
Cerebellum control is _________ in direction.
Damage to the right side of the cerebellum = problems controlling the _______ side of the body.
The cerebellum has _______ memory.
Why can the cerebellum make corrections during a movement?
It brings in information from your eyes and your vestibular system. (ex- the tennis player with cerebellum problems could play tennis just fine when the area around him was lit, because that light provided motor memory).
In the instance of the tennis player who had problems with coordinated movement, he could play just fine when the area around him was lit. This is because due to the light, this was in his ____________ memory.
The cerebellum allows a correction to be made during movement or as a __________ when the correction is being stored in the motor memory.
In cases of cerebellum damage, the alpha motor neuron is fine. The ___________ to the alpha motor neuron is affected.
The motor nervous system controls __________, fine _________, body __________- and __________.
locomotion, fine movements, body posture and equilibrium.
How does the motor nervous system control locomotion, fine movements, body posture and equilibrium?
By acting on motor neurons in the spinal cord that innervate skeletal muscles.
________ motor units are for fine movements.
_________ motor units are for strong force.
Motor neurons have _______- located in the __________ matter of the ________ horn of the spinal cord.
cell bodies, grey matter, ventral horn
The spinal cord contains interneurons which play a role in coordinating the response of _________ and ________ muscles to carry out intended movements.
The spinal cord also contains _________ movements initiated by _________ receptors.
Specific ________ systems provide input to the motor system.
Sensory receptors in muscle detect and regulate muscle _______- and the velocity of _________- (spindle) as well as _________ (golgi tendon)
length, stretch, tension
________- actions are initiated when sensory information is sent from muscle, tendon, or skin receptors to the spinal cord, causing movement in the appropriate muscles.
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