Term
|
Definition
“feedforward system”
- Requires experience
- moving smoothly and coordinated |
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Term
|
Definition
• Movement is dependent upon sensory input.
- Error correction
- response to unexpected environmental events |
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Term
|
Definition
- Can be controlled/modulated by higher cortical levels
- Involuntary movements
- always the same movement |
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Term
|
Definition
(Choice)
• Movement that is initiated/generated internally. This initiation is cortical
- Motor learning
• These movements are goal-directed and planned. |
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Term
|
Definition
• Groups of muscles will act together to support types of movements.
• The individual movements become linked and will act together.
- abnormal synergy would be shoulder AB duct when trying to lift forearm |
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Term
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Definition
| • Intermediate neurons that allow communication between neurons • They are very important for a number of functions, including modulating activity, reflexes, etc. |
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Term
|
Definition
• The neurons that go to the muscle that will be activated. Their termination is at a neuromuscular junction
• They have their cell bodies in the CNS and axons that go to IPSILATERAL groups of striated muscle fibers OUTSIDE the CNS |
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Term
|
Definition
• Synapse between the LMN and the striated muscle
• LMN will synapse on multiple muscle fibers. As a result, an action potential traveling along one LMN will cause multiple muscle fibers to contract.
• The neuromuscular junction is a chemical synapse using the neurotransmitter ACh ALWAYS.
- Can only cause a contraction
- To not contract --> inhibit the LMN
• ACh needs to be inactivated rapidly to allow the muscle to be ready for further action. Done through acetylcholinersterase (AChE) breaking the neurotransmitter down |
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Term
|
Definition
- One motor neuron, and all the interacting muscle fingers
• Multiple motor units that act together within a striated muscle are called a motor pool |
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Term
| Distinguish Voluntary compared to reflex |
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Definition
• It involves a decision to act
• It is learned
• It is under conscious control
• Makes use of other types of movement such as reflexes, reciprocal innervation |
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Term
|
Definition
• Large cell bodies and large, myelinated axons
• Synapse at the neuromuscular junction of EXTRAFUSAL striated muscle.
• These are the LMN that will cause muscle contraction and create movement
• MOST of the time we’ll talk about LMN, it’ll be alpha motor neurons. I’ll be specific if I discuss gamma motor neurons
- EXTRAFUSAL MUSCLES DO MOVEMENT |
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Term
|
Definition
• Medium-sized myelinated axons
• Synapse with the INTRAFUSAL fibers in the muscle spindle
• Important for maintaining sensitivity of the muscle spindle to stretch. Also important component of the stretch reflex (more later) |
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Term
|
Definition
| - Muscle spinal length is maintained so that it is sensitive to stretch |
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Term
|
Definition
- Cortex
-Brainstem
- Somatosensory Afferent fibers |
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Term
| Types of muscle fibers (3) |
|
Definition
• Red fibers (AKA slow-twitch fibers)
• Intermediate fibers (AKA fast twitch, fatigue-resistant fibers)
• White fibers (AKA fast-twitch, fatigable fibers) |
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Term
| Red AKA slow twitch fibers |
|
Definition
- Small amount of tension for a long time i.e. sit, stand
• Innervated by small alpha LMN with small axons
• Important for maintaining posture/position in quiet standing |
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Term
Intermediate AKA fast-twitch, fatigue-
resistant fibers |
|
Definition
• Able to provide fast and powerful muscle contraction but not use up too much oxygen while contracting.
• Innervated by alpha LMN of intermediate size
• Important for movement that isn’t too strenuous, such as walking |
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Term
| White AKA fast-twitch, fatigable fibers |
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Definition
- Sprinting
• Contract in brief, powerful twitches and rely on anaerobic catabolism
• Use a lot of energy
• Innervated by the largest alpha LMN
• Provide force for strenuous behavior like jumping |
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Term
|
Definition
• A myotome is the group of muscles that is innervated by a spinal nerve.
• These are similar to dermatomes, but for movement, though it’s not quite as clear cut because there is some overlap with myotomes |
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Term
|
Definition
• Defined as resistance to stretch in a resting muscle i.e. the way the muscle feels
• Continuous state of mild muscle contraction at rest – thought to be due to LOW LEVELS OF ALPHA LOWER MOTOR NEURON ACTIVITY
• Needed to maintain posture and positioning of body
• Unconscious phenomenon
• Depends on a variety of factors, including position of body, alertness, stress, etc.
• Most pronounced in antigravity muscles of trunk and proximal limbs |
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Term
|
Definition
• These are the neurons that send information to the LMN (directly or indirectly through interneurons)
• They have cell bodies rostral to the spinal cord. Their axons are also within the CNS. So no part of them leaves the CNS.
• Axons travel through descending tracts
- Excitatory and Inhibitory |
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Term
|
Definition
| - Higher center to muscles for movement |
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Term
|
Definition
• Innervates cranial nerves to allow voluntary control of face, head, and neck musculature
• MOST of the projections are bilateral
• The exceptions are the lower part of CN VII and CN XII which are innervated contralaterally. |
|
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Term
Corticobulbar Tract
If a person has a stroke that affects the LEFT primary motor cortex, what will the symptoms be? |
|
Definition
- most CN functioning won't be impacted since it is bilateral an intact RIGHT primary motor cortex can't take over
- but
- the loss of innervations on to the lower part of CN VII means a person can have a lower facial droop on the right.
- This combines with dysphagia and dysarthria |
|
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Term
| Spinal Cord Rules: Distal-proximal |
|
Definition
LMN in the ventral horn are organized so that those
innervating distal musculature are lateral. Those LMN that innervate proximal musculature are medial |
|
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Term
| Spinal Cord Rules: Flexor-extensor |
|
Definition
LMN in the ventral horn are organized so that those
innervating flexor musculature are dorsal. Those LMN that innervate extensor musculature are ventral. |
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Term
|
Definition
(Hand Movements)
flexor-mediated discrete movements of the distal musculature |
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Term
|
Definition
| extensor- mediated postural movements of the axial/proximal musculature |
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Term
| Anterior Corticospinal tract |
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Definition
|
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Term
| Lateral Corticospinal tract |
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Definition
|
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Term
|
Definition
• Important for:
• Voluntary movement, especially of the trunk and proximal musculature
• Posture
• Muscle tone
• Regulation of reflexes |
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Term
|
Definition
• From the reticular formation (pons and medulla) to the spinal cord
• Travels in the anterior funiculus
• Contributes to bilateral posture, gross motor movement, and some reflexes.
• Cortical input can modulate activity here. It is believed that the loss of cortical input to reticulospinal tract is what results in abnormal synergy after brain injury. |
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Term
|
Definition
• From the vestibular nuclei to the spinal cord
• Travels in the anterior funiculus
• Contributes to postural muscles and reflexes for helping with balance
• There are two of these pathways: the lateral vestibulospinal (trunk) and the medial vestibulospinal (neck and upper back) |
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Term
|
Definition
• From the superior colliculus to the spinal cord
• Travels in the anterior funiculus
• Helps control movement of the head and upper extremity |
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Term
|
Definition
• Within the spinal cord
• Axons travel in all funiculi
• Important for integrating activity across multiple spinal cord segments
INTEGRATE ACTIVITY |
|
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Term
|
Definition
Several structures can influence UMN activity, including the thalamus,
basal ganglia, and cerebellum
• These can assist with things like error correction and assisting with initiation of movement. |
|
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Term
|
Definition
• A receptor that receives an environmental stimulus
• An afferent fiber that carries information to the CNS
• A reflex center within the CNS – made up of interneurons (at least one)
• An efferent fiber to carry information from the reflex center
• An effector that receives the information and produces a response (Can be striated muscle, smooth muscle, or a gland) |
|
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Term
|
Definition
The set of interneurons that make up the reflex center of a reflex arc
• The interneuronal pool will determine the pattern of the reflex response (e.g. which muscles contract and which relax)
• The interneuronal pool is also the site where modulation from other CNS structures (e.g. cortex) takes place |
|
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Term
| Phasic (myotatic) stretch reflex |
|
Definition
• The patellar and biceps tendon reflexes are examples of stretch reflexes
• Hitting the tendon resulted in a brief and brisk stretch on the muscle
Two Proprioceptors:
• Muscle spindle
• Golgi tendon organ |
|
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Term
| Phasic stretch reflex (Steps) |
|
Definition
• When the patellar reflex is tapped, it stretches.
• That, in turn, causes the quadriceps to stretch, thus activating the muscle spindles
• A signal is sent via the Ia afferent fibers to the dorsal horn in the spinal cord
• Afferents synapse with ipsilateral alpha lower motor neurons in the ventral horn. (Remember no interneuron in this reflex arc)
• These alpha motor neurons send a signal back to the quadriceps muscle, causing contraction.
• The knee then extends. |
|
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Term
| Phasic stretch reflex (opposing muscle) |
|
Definition
• Need reciprocal innervation to happen as well.
• When the quadriceps contracts, knee extension can only happen if
the hamstrings relaxes.
• So there is another part of the reflex arc!
• That needs to happen by HYPERPOLARIZING the alpha lower motor neurons that go to the hamstrings |
|
|
Term
Phasic stretch reflex – part 2 (reciprocal
innervation) |
|
Definition
• The group Ia afferent fibers have branches that innervate other spinal levels.
• Some of those branches will synapse on interneurons in the intermediate gray and cause depolarization
• Those interneurons will, in turn, synapse on the alpha lower motor neurons that innervate the hamstrings and cause hyperpolarization.
• Note: this reflex is believed to be a contributing cause of spasticity |
|
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Term
|
Definition
CORRECTIONS
• Elicited by natural stretches from gravitational forces
• Important for helping maintain upright posture.
• When muscles are stretched in postural sway, there is a reflexive reaction that causes them to contract and correct positioning.
• To activate this reflex, the alpha lower motor neurons need to already be active
• The cortex helps to adjust the sensitivity of this reflex. the brain sends a signal to the GAMMA lower motor neurons to adjust the sensitivity of the muscle spindles. |
|
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Term
| Flexion withdrawal reflex |
|
Definition
IN CONTACT WITH NOXIOUS STIMULUS
Examples include something sharp (e.g. stepping on a tack) or hot (e.g. touching a hot stove)
• The result of this reflex is a withdrawal of the body part from the noxious stimulus. There is also extension of the opposite side of the body |
|
|
Term
Flexion withdrawal reflex (stepping on a tack
as an example) |
|
Definition
• Painful stimulus comes in from the free nerve endings in the affected area. Travel along A-delta fibers to the dorsal root in the spinal cord
• At that point, it will synapse with diverging interneurons that will differentially affect alpha lower motor neurons over a range of spinal segments (in this example, it’ll be about L2 to about S2)
• The result is the stimulation of all flexor groups in the affected leg with reciprocal innervation to relax all of the extensor flexor groups in that same leg.
SOME CORSS to other side of spinal cord |
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Term
|
Definition
| • The end result of the action of those interneurons is to cause extension of muscle groups on the contralateral leg with reciprocal innervation to inhibit the alpha motor neurons going to the contralateral leg’s flexors. |
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Term
| Cross Extensor Reflex: After Discharge |
|
Definition
| • The size of the reflexive action will be proportional to the noxiousness of the stimulus. If it is mildly noxious, the reaction will be small. If it is strongly noxious, the reaction will be much larger. |
|
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Term
|
Definition
• The pattern of movements will be different when different body parts are affected by the noxious stimulus.
NOT ALWAYS THE SAME MUSCLE ACTIVATING |
|
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Term
|
Definition
Conscious thought
- changes, not the same every time
• Truly skilled movement requires synthesis of information from other systems in addition to the motor system: somatosensory, vestibular, visual, limbic, and prefrontal areas all contribute, in addition to structures outside of the cortex, such as the cerebellum and basal ganglia.
- Limbic system can influence decisions with motivation aspects
- prefrontal is planning, decision making
- basal ganglion --> appropriate movements |
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Term
| Voluntary Movement (spinal cord) |
|
Definition
• The information about the specific muscles to contract comes from this point of the motor system – information received from higher up is more about the movement needed, rather than specific musculature to activate. (Gets plan and decisions implementation)
• The ability of the spinal cord to complete these basic movements without as much detail frees up higher CNS levels to plan movement and to execute more complex or whole body movement. |
|
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Term
|
Definition
Corticospinal tract (Lateral and anterior) --> distal trunk
corticobulbar tract --> facial cranial nerves
reticulospinal --> autonomic adjustments
vestibulospinal --> posture, eye movement
tectospinal --> posture eye movement |
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Term
| Voluntary movement - descending tracts |
|
Definition
• Allow information about voluntary movement to be sent from higher CNS structures to the lower motor neurons for execution
• Modulate reflexes
- inhibiter (shots at the doctor) |
|
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Term
| Voluntary movement – cortical essentials |
|
Definition
Essential for many aspects of voluntary movement:
• Planning
• Coordinating sequencing
• Making decisions about movement
• Evaluating the appropriateness and effectiveness of movement
• Sending information through the descending tracts to the lower motor neurons |
|
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Term
| Voluntary movement – cortical areas |
|
Definition
Motor areas in the frontal lobe:
• Primary motor cortex (AKA M1)
• Premotor cortex
• Supplemental motor cortex
Motor areas in the parietal lobe:
• Posterior parietal cortex
• Areas in the limbic system
• Prefrontal cortex |
|
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Term
| Primary motor cortex (M1) |
|
Definition
• Doesn’t control individual muscles (Mapped to an area)
• Instead, it sends a plan for movement, including the sequence (e.g. when grasping a cup, need to open hand as approach cup, stop hand at right time, and close hand), force, direction, extent, and speed.
• The alpha lower motor neurons will then translate the plan into action.
• Because M1 is sending a plan, it will fire before the muscles themselves. It will also send different plans, even for the same joint movement, depending on circumstances
(M1 sends the plan and LMN executes) |
|
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Term
|
Definition
• Aids in planning complex movement
• It will create a plan and then send the information to M1 (mostly) and
to the spinal cord
• This area is very important for preparation for the movement
• It will also fire differently when it perceives correct/incorrect movement |
|
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Term
|
Definition
(Sensory-motor association)
They will fire, not only when the individual is planning own movement, but also when watching another complete the movement. Or in response to sensory input associated with that movement |
|
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Term
| Supplementary motor areas (Memory of how) |
|
Definition
• Aids in planning complex movement
• Important for coordinating bilateral and/or sequential movements
• It creates programs based on memories of movements (as opposed to the premotor area that relies more on sensory input)
• Also involved in the mental rehearsal of actions/imagery. |
|
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Term
| Posterior parietal cortex |
|
Definition
• To move appropriately in space and to interact with objects and other people in the environment, need information about the environment surrounding oneself.
• Helps to provide spatial relationships between self and other objects and
between the objects themselves
• Gives information about position of own body
• Gives information about the properties of objects – such as size, shape, etc. |
|
|
Term
|
Definition
(Motivation)
• Important for emotion, memory, and drive
• These are essential for providing the motivation to move |
|
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Term
|
Definition
• Not a direct driver of movement, but definitely contributes by helping determine social appropriateness of movement.
• Contributes information about behavioral parts of movement – when to move as well as when NOT to move |
|
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Term
|
Definition
| Association cortices (posterior parietal cortex and prefrontal cortex) --> Motor cortex (supplemental motor area, premotor cortex, primary motor cortex) --> Brainstem --> Spinal cord --> Activation of muscle |
|
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Term
|
Definition
(Facilitate and Inhibit)
• Caudate
• Putamen
• Globus pallidus (AKA pallidum)
• Subthalamic nuclei
• Substantia nigra
• Nucleus accumbens |
|
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Term
|
Definition
(Automatic over learned movement, i.e. walking)
• Broken into three parts: head, body, tail
• C-shaped and follows the lateral ventricle
• Important for planning and execution of automatic movement patterns in addition to evaluation of movement
• Strongly connected with frontal lobe – contributes to motor planning
• Also important for INHIBITING movement
• amygdala is part of the limbic system |
|
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Term
|
Definition
• Largest nucleus in the basal ganglia
• It works in an opposite way from the caudate. It activates movement. |
|
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Term
|
Definition
• Broken into two parts, the INTERNAL and EXTERNAL segments
• Traversed by multiple myelinated fibers, which gives it a pale appearance
• The globus pallidus helps to inhibit unwanted/unnecessary movement |
|
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Term
|
Definition
• Located in the midbrain, but functionally associated with the basal ganglia
• Largest nucleus of the midbrain
• Important for dopamine production |
|
|
Term
| Substantia nigra - two parts |
|
Definition
• Pars compacta (cell-rich)
• Pars reticulate (cell-sparse) |
|
|
Term
|
Definition
• Located caudal to the thalamus
• Appears to be important for contributing to feedback/feedforward
circuits of thalamus and basal ganglia
• Damage to the subthalamic nucleus leads to some of the characteristic signs of basal ganglia dysfunction.
(parkinsons & Huntington's disease) |
|
|
Term
|
Definition
(addiction)
fused with interconnections of caudate and putamen |
|
|
Term
|
Definition
| putamen and globus pallidus |
|
|
Term
|
Definition
| caudate, putamen, and globus pallidus |
|
|
Term
|
Definition
| striatum (caudate or putamen) to globus pallidus |
|
|
Term
|
Definition
| globus pallidus to thalamus |
|
|
Term
|
Definition
| substantia nigra to thalamus |
|
|
Term
|
Definition
| substantia nigra to corpus striatum |
|
|
Term
| Basal Ganglia Neurotransmitter |
|
Definition
• GABA (inhibitory)
• Dopamine (both excitatory and inhibitory)
• Acetylcholine (works in opposition to dopamine)
BALANCE HOMEOSTASIS --> structures work together to fine tune structures
Parkinsons --> not enough dopamine, too much ach |
|
|
Term
| Pathways - Ansa Lenticularis |
|
Definition
| travels from the globus pallidus to the ventrolateral nucleus in the thalamus, primary motor area, and premotor area |
|
|
Term
| Pathways - Lenticular fasciculus |
|
Definition
| travels from the globus pallidus to the subthalamus, reticular formation, and substantia nigra |
|
|
Term
| Pathway - Afferent basal ganglia pathway |
|
Definition
| primary motor area and premotor area send signals to the caudate, putamen, and globus pallidus |
|
|
Term
| Pathway - Nigrostriatal pathway |
|
Definition
| from the substantia nigra to the globus pallidus and subthalamus. Modifies action of the ansa leticularis. This is lost in Parkinson’s disease |
|
|
Term
| Basal ganglia and the thalamus |
|
Definition
| • Ventroanterior and ventrolateral nuclei are important for movement • Dorsomedial nucleus is important for cognition |
|
|
Term
| Functions of the basal ganglia |
|
Definition
• Very important role in motor behavior. ESPECIALLY for automatic/overlearned movement
• Increasingly implicated in cognition, including things that require timing (e.g. turn-taking in conversation) and choosing desired behavior/preventing undesired behavior
(deficits can lead to dementia)
• One of its roles is in allowing people to complete parallel processing (doing more than one thing at a time)
• Part of the reward system
• These different functions are controlled by different loops |
|
|
Term
| Loops and Basal Ganglion: Oculomotor |
|
Definition
• Important for regulating eye movement, including initiation of fast eye
movements. Also contributes to spatial attention.
• Projects from the caudate to the frontal eye fields and the supplementary eye fields |
|
|
Term
| Loops and Basal Ganglion: Prefrontal/EF/Behavioral Flexibility |
|
Definition
• Important for cognition, including goal-directed behavior and planning, including choosing actions in context
(deciding to run a yellow light) |
|
|
Term
| Loops and Basal Ganglio: Limbic |
|
Definition
• Important for regulation of emotions and motivation (including reward system) – helps to identify value of stimuli. Important for pleasure seeking
• Input from numerous areas, including the limbic system, hippocampus, and amygdala. Input goes to the nucleus accumbens and ventral striatum
• Output to the medial dorsal and ventral anterior nucleus of the thalamus and to the limbic cortex
(huntingtons impulsive and paranoid personality) |
|
|
Term
| Loops and Basal Ganglion: Movement (2) |
|
Definition
• The direct loop FACILITATES/INITIATES movement
• The indirect loop INHIBITS movement
The basal ganglia BOTH facilitate AND inhibit movement. So where there are deficits, there can be EITHER too much OR not enough movement (or both) |
|
|
Term
| Direct Pathway/Loop of the Basal Ganglia |
|
Definition
• Information from the CORTEX signals that movement is needed.
(+)
• STRIATUM
(-)
• GLOBUS PALLIDUS (INTERNAL)
(inhibition stops)
• THALAMUS
(+)
• MOTOR CORTEX |
|
|
Term
|
Definition
• Association cortices (posterior parietal cortex and prefrontal cortex)
• Motor cortex (supplemental motor area, premotor cortex, primary motor
cortex)
• Brainstem
• Spinal cord |
|
|
Term
|
Definition
• The basal ganglia do not initiate movement on their own (no direct connections to lower motor neurons).
• Instead, they influence the processing of motor control and modulate the output of the descending pathways
• Their exact function is not fully understood. Appear to be involved in implementation of “overlearned” movement
• Basal ganglia moderate voluntary movement through direct and indirect loops.• The basal ganglia do not initiate movement on their own (no direct connections to lower motor neurons).
• Instead, they influence the processing of motor control and modulate the output of the descending pathways
• Their exact function is not fully understood. Appear to be involved in implementation of “overlearned” movement
• Basal ganglia moderate voluntary movement through direct and indirect loops.
- Parts of the basal ganglia inhibit and not allow movement
• As we work through these pathways, remember the end result! Direct FACILITATES movement. Indirect INHIBITS movement. |
|
|
Term
|
Definition
• The thalamus, left unchecked, will send signals to the motor cortex to stimulate movement
• As a result, the thalamus is normally inhibited.
• To allow movement to be initiated, the inhibition on the thalamus needs to be removed. |
|
|
Term
| The direct pathway/loop of the BG |
|
Definition
[image]
Substantia nigra will activate dopamine in striatum making the inhibitory signal stronger to shutdown globus pallidus. Substantia nigra turns up the volume.
- Sends a signal to the sub thalamic nuclei; I got it
- Does the job even better increasing inhibition |
|
|
Term
| The indirect pathway/loop of the BG |
|
Definition
|
|
Term
| Communication and the cerebellum |
|
Definition
• ALL fibers exiting the cerebellar cortex (the outer layer of the cerebellum) are axons of Purkinje neurons
• Most Purkinje axons synapse in the cerebellar nuclei, which are deep within the cerebellum.
- They synapse
- EXCEPTION IS CEREBELLOVESTIBULAR tract |
|
|
Term
| Cerebellum and motor learning |
|
Definition
| - repeated practice of over learned automatic movement. BG responsible, but cerebellum contributes. |
|
|
Term
|
Definition
| This can be present in numerous places in the body, including the face/tongue, which can cause dysarthric speech. Can extend to oculomotor control with nystagmus present. |
|
|
Term
Cerebellum and coordination of voluntary
movements |
|
Definition
• Coordinates timing and force of different muscle groups to produce fluid movement.
• Important cerebellar structures are the vermis and the inputs from sensory systems to allow for error checks |
|
|
Term
| Cerebellum and maintenance of balance |
|
Definition
• Maintains balance through inputs from the vestibular system and the proprioceptors
• Allows compensation for shifts in body position, or loads upon the muscles
• Important parts of the cerebellum for this job are the flocculonodular lobe and its connections to vestibular and proprioceptive nuclei |
|
|
Term
Voluntary movement and the cerebellum side
loop |
|
Definition
• This loop has a few (motor related) jobs:
• Maintaining posture and balance
• Coordinating voluntary movement
• Motor learning |
|
|
Term
|
Definition
Ataxia
after posterior lobe damage to the cerebellum |
|
|
Term
| Lesions of the cerebellum |
|
Definition
• Increasing evidence that damage can lead to cognitive deficits, including issues with shifting attention and responding appropriately to social situation.
• May be involved with people with autism spectrum disorder, ADHD, a variety of mental illnesses.
STILL A LOT NOT KNOWN |
|
|
Term
|
Definition
Flocculonogular lobe
• Most common cause of damage to this part of the cerebellum is medulloblastoma, a highly malignant tumor. Most often occurs in children between ages 4 and 8.
• Signs/symptoms include:
• Vomiting, headache, papilledema – from increased intracranial pressure
• Unsteady, stumbling gait
• Frequent falling
• Difficulty moving against gravity due to vestibular control issues (movement while supine is fine)
• Vestibulo-ocularcontroldeficits |
|
|
Term
|
Definition
Posterior Lobe
• Most common type of cerebellar dysfunction. Can occur with numerous diseases/disorders including:
• Metastatic tumors
• Multiple sclerosis |
|
|
Term
| Neocerebellar syndrome S/S |
|
Definition
• Signs/symptoms:
• Intention tremor
• Hypotonia (not always present) – may result in signs like slowed/decreased
stretch reflexes
• May have weakness, called asthenia
• Difficulty with coordinating complex movements involving more than one
joint/muscle group
• Ataxia (including with speech) – results in dysarthria
• If only one hemisphere involved, symptoms will be on ipsilateral side of body only. |
|
|
Term
| Cerebellar Cognitive Affective Syndrome |
|
Definition
• Constellation of symptoms, which can include:
• Disinhibition, blunted affect, impulsivity
• Obsessivebehaviors
• Problems with planning and anticipating consequences
• Problems in working memory and abstraction
• Emotional regulation dysfunction
• Perseveration
• Distractibility and inattention |
|
|
Term
|
Definition
LMN --> smaller amount o muscles if lesion
UMN --> bigger amount of muscles if lesion |
|
|
Term
| Damage in the motor system |
|
Definition
- paresis or paralysis
- muscle atrophy
- involuntary muscle contractions (spasms, fasciculations, tremors, clonus etc)
- hypotonic or hypertonic
- hyporeflex or hyperreflex |
|
|
Term
|
Definition
flaccidity will occur
hyporeflexia
atrophy of muscles
muscles twitch (fasciculations
damage will be limited to muscles innervated by the specific LMN.. Motor loss is based on affected myotome |
|
|
Term
|
Definition
- Spacicity below the lesion area, spinal reflex stay intact --> they get hypotonicity in acute state
- broader involvement of muscle groups
- hyperactive reflexes
- cortical injury --> paresis than paralysis, some movement, but not beautiful skilled movement |
|
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Term
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Definition
• Controls the viscera, which includes cardiac muscle, smooth muscle, and glandular tissue
• Directly or indirectly receive cortical, hypothalamic, brain stem, and spinal cord input.
• Responds to both internal conditions and external stresses |
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Term
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Definition
• Two efferent subsystems: sympathetic and parasympathetic
• Most viscera are innervated by both subsystems. Exceptions are the sweat glands, somatic blood vessels, hair follicles, and adrenal medulla - only sympathetic innervation.
• In many places with duel innervation, the sympathetic and parasympathetic actions are in opposition to each other.
- REPRODUCTION
- HYPOTHALAMUS
• ANS also typically has a two neuron system between the CNS and the target; somatic system has one. |
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Term
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Definition
- Coming into spinal cord --> dorsal horn and synapse in intermediate zone of gray matter spinal cord
- Coming into CN IX and X |
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Term
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Definition
- the discomfort is referred to an area on the body’s surface where it is misinterpreted as being somatic in nature.
- the visceral and somatic afferents converge on common spinal cord neurons. When the information reaches the somatosensory cortex, the brain can’t locate the noxious stimulus. |
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Definition
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Term
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Definition
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Term
| ANS efferents from the CNS |
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Definition
- preganglionic axons - leave the ventral root
- postganglionic neurons - synapse cite --> cell bodies are outside the CNS |
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Term
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Definition
- signal reaches the viscera it travels quickly through the organ
COMMUNICATES THROUGH ELECTRICITY, NO CHEMICAL
- a single smooth muscle cell is stimulated by an action potential, it contracts AND the action potential is quickly spread to adjacent muscle cells.
• This allows a steady wave on contraction. Needed for things like heart contraction and peristalsis action in the gut. |
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Term
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Definition
• Sympathetic
• Parasympathetic
they work in conjunction
• They differ in their sites of origin in the CNS, neurotransmitters used, and their general functioning. Both important for allowing appropriate functioning of the body. |
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Term
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Definition
• Actions include:
• Accelerating heart rate
• Accelerating respiratory rate
• Diverting blood from gastrointestinal tract to the brain and skeletal muscles • Promoting sweating
• Erection of hair shafts (“goose bumps”)
• Peripheral vasoconstriction (except the heart) |
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Term
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Definition
T1 - L2/3
• Preganglionic axons are lightly myelinated and exit in the ventral roots
• Typically has short preganglionic axons and long postganglionic fibers
• MOST synapse with cell bodies of postganglionic neurons in the paravertebral ganglia |
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Term
| Preganglionic axons follow one of three courses: |
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Definition
• Synapse immediately with postganglionic neurons at the same level as where
they entered the sympathetic trunk
• Ascend or descend in the sympathetic trunk to synapse in a more cranial or caudal location
• Continue through the sympathetic trunk to emerge in the abdominopelvic splanchnic nerves |
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Term
| Sympathetic subsystem: T1-5 ascending preganglionic axons |
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Definition
| • Some preganglionic fibers from T1-5 ascend to cervical region where they synapse with postganglionic neurons in the cervical ganglia (inferior, middle, superior). |
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Term
| Postganglionic neurons from the cervical ganglia functions: |
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Definition
• Dilator muscles of the iris (to allow more light to enter eye)
• Lacrimal glands for producing tears
• Salivary glands
• Small blood vessels in the oral and nasal cavities
• Blood vessels, hair follicle muscles (“hair standing on end”), sweat glands of face and scalp
• Actions of the thyroid gland
• Join the cardiac plexus |
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Term
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Definition
• Network of vagal, sensory, and sympathetic postganglionic fibers
• Goes to the heart and great cardiac vessels |
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Term
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Definition
• Pulmonary plexus: network of vagal, sensory, and sympathetic postganglionic fibers that go to the lungs and bronchi
• This branch of the sympathetic subsystem induces relaxation of smooth muscle in the bronchial tree and inhibition of bronchial mucosecretion. This makes respiration EASIER. |
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Term
| Sympathetic subsystem: T5-12 |
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Definition
splanchnic nerve
• affect the gastrointestinal (GI) tract to inhibit motility and secretion and stimulate contraction of the pyloric and ileocecal sphincter muscles.
• Also cause vasoconstriction to GI vessels |
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Term
| Sympathetic subsystem: L1-L2/3 |
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Definition
superior hypogastric plexus and join the pelvic plexus terminating in pelvic and perineal viscera
• Dilates blood vessels of lower extremities (so can run away!)
• Stimulate muscular contraction and glandular secretion necessary for
ejaculation in men
• Important for contraction of uterine and uterine duct musculature in women |
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Term
Sympathetic subdivision
• Neurotransmitters: |
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Definition
• Acetylcholine (Ach) at the terminals of the preganglionic fibers
• Norepinephrine (NE) at the terminals of the postganglionic fibers (mostly) – enhances blood flow to skeletal muscle, increases heart and respiratory rates, raises blood pressure and blood sugar level |
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Term
| Sympathetic preganglion exception |
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Definition
| adrenal medulla (above the kidneys) where they cause release of epinephrine and norepinephrine directly into the bloodstream where they act as hormones. |
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Term
| Parasympathetic subsystem |
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Definition
| • Preganglionic fibers originate from neurons in the brainstem (C.N. III, VII, IX, and X) and the sacral spinal cord (S2-4 segments) (craniosacral) |
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Term
| Parasympathetic subsystem |
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Definition
the anterior nucleus and the periventricular nucleus of the hypothalamus
• From the hypothalamus, axons project down the brainstem via the dorsal longitudinal fasciculus |
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Term
| Parasympathetic subsystem (CN III) |
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Definition
• Branch of the oculomotor nerve
• Preganglionic fibers from the Edinger Westphal nucleus travel to the ciliary ganglion in the eye.
• Axons travel from here into the eyeball and innervate the ciliary muscles and pupillary constrictor muscles of the iris
• Contraction of the ciliary muscles facilitate visual accommodation
• Pupillary constriction helps to reduce amount of light entering the eye. |
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Term
| Parasympathetic subsystem (CN VII) |
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Definition
• Branch of the facial nerve
• Preganglionic fibers from the superior salivatory nucleus travel to the
pterygopalatine and submandibular ganglia.
• Postganglionic fibers from the pterygopalatine promote secretions of the lacrimal gland (tearing) and glands of nasal and oral mucus membranes
• Postganglionic fibers from the submandibular ganglion stimulate secretions from the submandibular and sublingual salivary glands |
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Term
| Parasympathetic subsystem (CN IX) |
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Definition
• Branch of the glossopharyngeal nerve
• Preganglionic fibers from the inferior salivatory nucleus travel to the otic ganglion.
• Postganglionic fibers from here promote secretions of the parotid salivary gland |
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Term
| Parasympathetic subsystem (CN X) |
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Definition
RESPIRAITON, DIGESTION, A LOT
• Branches of the vagus nerve
• Preganglionic fibers travel to numerous structures where they synapse on intramural ganglia. These are located in organs of the neck, bronchial tree, lungs, esophagus, GI tract, liver, gallbladder, pancreas, and kidneys.
• In the thorax, vagal stimulation reduces heart rate, slows respiratory rate, constricts bronchial passageways, increases bronchial secretion, enhances esophageal peristalsis, and induces motility in the alimentary canal from esophagus to anus |
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Term
| Parasympathetic subsystem (S2-4) |
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Definition
• Begins in neurons of the lateral horn
• When leave the spinal cord, form the pelvic splanchnic nerves and project to pelvic and perineal viscera including colon, rectum, bladder, and reproductive organs.
• Stimulate contraction of the bladder during urination and erection of the penis and clitoris |
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Term
Parasympathetic subsystem
• Neurotransmitters: |
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Definition
• Acetylcholine (ACh) at the terminals of the preganglionic fibers AND at the
terminals of the postganglionic fibers.
• Release of ACh by postganglionic fibers encourages secretomotor activity of the GI tract, reduces heart and respiratory rates, and increases blood flow to the viscera |
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Term
| Primary (Idiopathic) Orthostatic Hypotension |
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Definition
BLOOD PRESSURE DROPS
• Blood pressure falls suddenly upon standing from supine
• Veins in the legs fail to constrict, with lower venous return and diminished cardiac output
• Several subtypes but causes unknowns
• One has degeneration of postganglionic sympathetic fibers. In another, there is degeneration of the preganglionic intermediolateral cell column neurons
• In addition to hypotension, can get disturbances of sweating, bladder, and sexual functions |
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Term
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Definition
• Storage of urine and emptying of bladder is complex, depending on reflex connections between spinal cord segments and pons and the connections between bladder and spinal cord.
• Interruption produces a neurogenic bladder |
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Term
reflex
neurogenic [spastic] bladder |
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Definition
• Spinal cord injury above T12 result in paralysis of the bladder
• Can’t feel when bladder full.
• Voluntary control of bladder is lost
• When bladder empties (reflexively), it doesn’t empty completely |
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Term
| nonreflex neurogenic bladder |
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Definition
• Bladder will distend beyond where it should. • Dribbling incontinence occurs
• Also get urinary retention
• Cannot feel when bladder full |
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Term
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Definition
• Potentially life threatening
• Occurs after SCI, most likely when lesions at T6 and above occur.
• In this case, there is some type of noxious sensory input (e.g. kinked catheter, wound, bladder or bowel distension). Cannot be felt.
• Causes activation of sympathetic ANS and causes vasoconstriction with increases in cardiac output. Blood pressure rises dangerously high, person experiences severe headache, good bumps, and sweating. May also have feelings of anxiety or dread. |
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