192 Questions
Which receptors send a signal as long as a stimulus continues to be present and does not ease or fatigue with time?
Tonic receptors
In the peripheral somatosensory system, which neurons are in the thalamus and communicate to the cerebral cortex?
3rd order neurons
What type of receptors will quickly adapt to a signal that is being sent and will fatigue or stop responding despite the presence of an ongoing stimulus?
Phasic receptors
Which part of the nervous system works on a three-order neuronal pathway for a signal to be sent to the periphery?
Central nervous system
Which receptors are aware the same as the autonomic nervous system and can be classified as tonic or phasic?
Cutaneous receptors
Which nervous system component allows us to sense things such as temperature, pain, pressure, or stretch?
Peripheral nervous system
Where are the 2nd order neurons located in the three-order neuronal pathway for a signal to be sent to the periphery?
Spinal cord or brainstem
Which part of the nervous system includes the sympathetic and parasympathetic nervous systems?
Autonomic nervous system
Which of the following structures is NOT a part of the Pain Matrix?
Hypothalamus
What is the primary function of the Pain Matrix?
Signaling and processing of pain
Which neurotransmitter is responsible for inhibiting the transmission of nociceptive signals in the spinothalamic tract?
Enkephalin
What term is used to describe the phenomenon where an area of the spinal cord is altered or injured, leading to suboptimal integration and regulation of signals?
Reorganized state
Which modality can facilitate the release of enkephalin through the interneurons in the dorsal horn?
Heat
What is the term used to describe the top-down inhibition of pain signals?
Antinociception
Which area of the brain is responsible for the mediation of pain sensation by the emotional and motivational systems?
Amygdala
What term is used to describe the phenomenon where all areas of the brain become active in response to a single painful stimulus?
Distributed responsibility
Which part of the nervous system is responsible for the actual experience of pain?
Central nervous system
What term is used to describe the phenomenon where a stimulus is likely to induce a pain response where normally it does?
Allodynia
Which modality can prevent the activation of nociceptors throughout the body?
Aspirin
Which area of the brain can intensify the experience of pain input?
Somatosensory association cortex
What type of information do muscle spindles provide?
Both phasic and tonic information
What is the role of Golgi tendon organs?
Sensing muscle contraction and passive stretch
What type of information does the intact sensory system provide to the brain?
Crucial information for joint position awareness, muscle length, and pain and temperature signals
What is the function of the homunculus on the primary somatosensory cortex?
Depicting a somatotopic map of sensory information
What type of information do conscious relay paths carry to the cerebral cortex?
High-fidelity information on light touch
What distinguishes nonconscious relay pathways?
The type of conveyed information
What is the role of alpha and gamma motor neurons in muscle spindle activation?
Co-activating intrafusal and extrafusal muscle spindles
Where are Golgi tendon organs located?
In muscle tendons
What do joint receptors play active roles in detecting?
Joint movement
What type of information do divergent paths carry toward the brainstem and cerebrum?
Wider networks of neurons and pathways
Which type of nerve endings sense coarse touch, pain, and temperature?
Free nerve endings
Which type of nerve ending is positioned to sense stretch?
Ruffini’s ending
What type of neurons are the largest in diameter and fastest in signal transmission speed?
A (alpha) neurons
What do muscle spindles provide information on?
Overall length of muscles and rate of change
Which type of receptor senses fine details of touch?
Merkel’s disks
What is crucial for physical therapists to know for testing sensation and identifying lesions or problems in the body?
Dermatomes and cutaneous distributions
What do Pacinian corpuscles respond to?
Deep pressure and high-frequency vibration
What are receptive fields in the hands compared to those in the torso?
Smaller
What is sensory innervation categorized as?
Dermatome or cutaneous nerve distribution
What do sensory nerve conduction studies measure?
Distal latency, amplitude of evoked potential, and conduction velocity
What is the basis for regional sensation?
Dermatome or cutaneous distribution
What is important for differential diagnosis and impairment testing?
Dermatome and cutaneous innervation
Which tract carries information on crude touch in the anterolateral column?
Anterior spinothalamic tract
Where do signals from upper body or arms travel in the dorsal column-medial lemniscus system?
More laterally in the fasciculus cuneatus tracts
Where does the spinoreticular tract terminate?
Reticular formation of the midbrain
Which tract targets periaqueductal gray and superior colliculus on the midbrain?
Spinomesencephalic tract
Where do signals from upper trunk and upper limb go in the dorsal column-medial lemniscus system?
Contralateral nucleus cuneatus
Which tract carries information on discriminative pain and temperature in the anterolateral column?
Lateral spinothalamic tract
Where do signals from legs travel in the dorsal column-medial lemniscus system?
Medially in the fasciculus gracilis tract
Where do signals from upper body or arms travel in the anterolateral column?
Dorsal horn of spinal cord to contralateral VPL nucleus of thalamus
Where do divergent tracts convert pain signals?
Insula
Where do signals from upper body or arms travel in the anterolateral column?
Contralateral brain
What is the role of a motor unit?
Activating alpha motor neurons and muscle fibers specific to a particular muscle region
What is the primary function of muscle synergies in a healthy normal system?
Coordinating timing, degree, and inhibition of muscle action
What is the process of reciprocal inhibition in muscle contraction?
Sensing change in muscle length and activating interneurons to inhibit the antagonist muscle
What is the significance of the spinal level in the movement of a joint?
It is important for assigning specific movements to a joint based on the innervating myotome
What is the function of alpha motor neurons in muscle spindle activation?
Regulating the sensitivity and responsiveness of the muscle spindle to changes in muscle length
What is the term used to describe the phenomenon where there is a complete disconnect between the midbrain and pons, resulting in extension of arms and flexion of wrists?
Deceberate
Which type of lesion results in a lack of muscle activation, hypotonia, hyporeflexia, and areflexia?
Lower motor neuron lesion
What is the term used to describe the resistance within a muscle being stretched, which can be either normal or abnormal?
Muscle tone
Which of the following is a characteristic of an upper motor neuron lesion?
Loss of fractioned movement
What is the term used to describe the change in muscle due to altered neuromuscular activity or prolonged position, leading to shortened muscle or contracture?
Myoplasticity
Which type of nerve ending is positioned to sense stretch?
Pacinian corpuscles
Where are Golgi tendon organs located?
In the tendons
Which motor tracts are responsible for controlling posture and muscle innervation?
Reticulospinal and vestibulospinal tracts
What is the function of the nonspecific motor tracts, such as the ceruleospinal and raphespinal tracts?
Regulating emotional motor responses
What type of information do muscle spindles provide?
Information about muscle length changes
Where are the cell bodies for the medial corticospinal tract located?
Medial anterior horn of the gray area of the spinal cord
Which tract responds to signals coming from the inner ear, helping orient the body towards gravity?
Lateral Vestibulospinal Tract
Where do the Lateral Tracts in the spinal cord primarily target?
Distal limb movement and fractionation of movements
Where do the Rubrospinal Tract cell bodies originate?
Red nucleus in the midbrain
Which motor system dysfunction involves repeated, involuntary, rhythmic contractions of a single muscle group?
Clonus
What is the term used to describe the group of muscles innervated by a single spinal nerve?
Myotome
Which region of the spinal cord is important for the assigned movement of a joint?
Cervical region
What is the term used to describe the phenomenon where one muscle contracts, leading to the inhibition of the antagonist muscle to prevent injury?
Reciprocal inhibition
What term is used to describe the coordinated timing, degree, and inhibition of muscle action in a healthy normal system?
Muscle synergies
What is the term used to describe the resistance within a muscle being stretched, which can be either normal or abnormal?
Muscle tone
Where are the cell bodies for the lateral corticospinal tract located?
In the premotor cortex
What is the primary function of the rubrospinal tract?
Initiating distal limb movement and fractionation of movements
Which tract primarily innervates distal limb movement and fractionation of movements?
Medial corticospinal tract
Where do signals from the inner ear travel in the spinal cord?
Lateral Vestibulospinal Tract
What is the function of the medial motor tracts?
Providing signals for bilateral control of axial and upper girdle muscles
Which of the following is not a characteristic of myoplasticity?
Increased muscle tone leading to hypotonia
What is the term used to describe a phenomenon where there is a complete disconnect between the midbrain and pons, resulting in extension of arms and flexion of wrists?
Deceberate
What is the primary difference between upper motor neuron lesions and complete motor neuron lesions?
Upper motor neuron lesions result in hypertonia, while complete motor neuron lesions result in hypotonia.
What is the term used to describe the resistance within a muscle being stretched, which can be either normal or abnormal?
Muscle tone
What is the characteristic presentation of a lower motor neuron lesion?
Hypotonia and hyporeflexia
Which structure is responsible for informing about tendon tension and lengthening, affecting muscle activation through spinal interneurons?
Golgi tendon organ
What initiates a reflex in the spinal cord by activating afferent nerves?
Phasic stretch
What type of reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input?
Withdrawal/crossed extension reflex
Which test locates areas of damage along muscle activation, helping to identify problems in motor nerves, neuromuscular junctions, or muscles?
Motor nerve conduction velocity tests
Which type of motor tracts are responsible for controlling posture and muscle innervation?
Medial motor tracts
What is a motor unit?
Alpha motor neurons and muscle fibers that activate it
What is the function of muscle synergies in a healthy normal system?
Coordinates timing, degree, and inhibition of muscle action
What is the role of reciprocal inhibition in muscle contraction?
Signals to inhibit contraction of antagonist muscle to prevent injury
What is the significance of the spinal level in the movement of a joint?
The spinal level is important for the assigned movement of a joint
What is the function of the myotome in the motor system?
Group of muscles innervated by a single spinal nerve
Which type of reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input?
Crossed extension reflex
What is the function of the medial motor tracts, including the reticulospinal, medial vestibulospinal, and lateral vestibulospinal tracts?
Coordinating posture and muscle innervation
What type of lesion results in heightened muscle activity with needle electromyography?
Upper motor neuron lesion
What do vertical motor tracts within the spinal cord convey signals for?
Gross motor movements
What is the role of the Golgi tendon organ in muscle activation?
Regulating muscle tension and lengthening
Which of the following is a characteristic of a lower motor neuron lesion?
Muscle flaccidity and hyporeflexia
What is the term used to describe a phenomenon where there is a complete disconnect between the midbrain and pons, resulting in extension of arms and flexion of wrists?
Decerebrate posturing
What distinguishes an upper motor neuron lesion from a complete motor neuron lesion?
Hyperreflexia and hypertonia
What type of motor system dysfunction involves repeated, involuntary, rhythmic contractions of a single muscle group?
Clonus
What is crucial for physical therapists to know for testing sensation and identifying lesions or problems in the body?
Pattern and type of motor impairment
Where are the cell bodies for the lateral corticospinal tract located?
In the lateral anterior horn of the gray area of the spinal cord
What is the primary role of the Rubrospinal Tract?
Facilitating fine motor movements in the distal limbs
What is the distinguishing feature of the Medial Motor Tracts?
They provide signals for bilateral control of axial and upper girdle muscles
What is the function of the Reticulospinal Tract?
Sending signals to both ipsilateral and contralateral motor neurons at the spinal level
What is the primary function of the Lateral Vestibulospinal Tract?
Responding to signals coming from the inner ear to orient the body towards gravity
What is a motor unit?
Alpha motor neurons and muscle fibers that activate it
What is the role of reciprocal inhibition in muscle contraction?
One muscle contracts, leading to the inhibition of the antagonist muscle to prevent injury
What does a myotome refer to?
A group of muscles innervated by a single spinal nerve
What is the function of muscle synergies?
Coordinates timing, degree, and inhibition of muscle action in a healthy normal system
What is the term used to describe the resistance within a muscle being stretched, which can be either normal or abnormal?
Hypertonia
What is the term used to describe the phenomenon where there is a complete disconnect between the midbrain and pons, resulting in extension of arms and flexion of wrists?
Deceberate
What is the primary difference between upper motor neuron lesions and complete motor neuron lesions?
Hyperreflexia
What is the term used to describe the change in muscle due to altered neuromuscular activity or prolonged position, leading to shortened muscle or contracture?
Myoplasticity
Which term refers to the phenomenon where there is a complete disconnect between the midbrain and pons, resulting in extension of arms and flexion of wrists?
Decorticate
What is the primary function of the rubrospinal tract?
Facilitation of voluntary movements
What distinguishes an upper motor neuron lesion from a complete motor neuron lesion?
Hyperreflexia
What is the role of reciprocal inhibition in muscle contraction?
Inhibition of antagonist muscles
What type of neurons are the largest in diameter and fastest in signal transmission speed?
Alpha motor neurons
What is important for differential diagnosis and impairment testing?
Identification of upper and lower motor neuron lesions
What is the term used to describe the phenomenon where there is an abnormal increase in resistance within a muscle being stretched?
Spasticity
What is the primary function of muscle synergies in a healthy normal system?
Coordination of muscle groups
Where are the cell bodies for the Medial Corticospinal Tract located?
Medial anterior horn of the gray area of the spinal cord
Which tract primarily innervates axial and girdle musculature, facilitating posture and core strength?
Medial Corticospinal Tract
Where do signals from the inner ear travel to, in order to orient the body towards gravity?
Lateral Vestibulospinal Tract
Where do the cell bodies for the Lateral Corticospinal Tract originate?
Primary motor cortex
Which tract begins in the reticular formation of the brainstem and sends signals to both ipsilateral and contralateral motor neurons at the spinal level?
Reticulospinal Tract
Which motor system dysfunction involves repeated, involuntary, rhythmic contractions of a single muscle group?
Clonus
Where do the Medial Motor Tracts arise from within the cortex?
Primary motor cortex
Which tract primarily innervates distal limb movement and fractionation of movements?
Lateral Corticospinal Tract
Where does the Rubrospinal Tract begin?
Red nucleus in the midbrain
Which tract responds to signals regarding head movement and position, activating and coordinating muscle activity in the neck and upper back?
Medial Vestibulospinal Tract
Which tract starts at the premotor cortex and descends downwards through the spinal cord?
Lateral Corticospinal Tract
Where are the cell bodies for the Reticulospinal Tract located?
Reticular formation of the brainstem
What type of signaling provides proprioception, informing about the body's position in space and time?
Type 2 afferent signaling
Which structure informs about tendon tension and lengthening, affecting muscle activation through spinal interneurons?
Golgi tendon organ
What is responsible for coordinating a rudimentary stepping pattern by connecting sensory and motor signals at or near the spinal level?
Highway of interneurons
What type of stretch activates afferent nerves to the spinal cord, initiating a reflex?
Phasic stretch
Which reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input?
Crossed extension reflex
What tests locate areas of damage along muscle activation, helping to identify problems in motor nerves, neuromuscular junctions, or muscles?
Motor nerve conduction velocity tests
What measures electric activity in muscles, aiding in understanding the location of lesions in the motor nervous system?
Electromyography
What results in heightened muscle activity with needle electromyography?
Motor neuron lesions
What can be identified through electromyography and nerve conduction studies?
Myopathy
Which motor tracts convey signals for movement and muscle activation to different parts of the body?
Vertical motor tracts
Which motor tracts are responsible for controlling posture and muscle innervation?
Medial motor tracts
Which motor tracts form the emotional motor system, impacting movement in response to emotions?
Nonspecific motor tracts
What is a motor unit?
Alpha motor neurons and muscle fibers that activate it
What is the function of reciprocal inhibition in muscle contraction?
To inhibit contraction of antagonist muscles to prevent injury
What is the role of muscle synergies in a healthy normal system?
Coordinates timing, degree, inhibition of muscle action
Why is communication of sensory, motor & interneurons important?
To facilitate reciprocal inhibition and muscle synergies
What is the term used to describe the resistance within a muscle being stretched, which can be either normal or abnormal?
Hypertonia
What is the characteristic presentation of a lower motor neuron lesion?
Hyporeflexia, hypotonia, paralysis
Where are the cell bodies for the lateral corticospinal tract located?
Cerebral cortex
What type of reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input?
Flexor withdrawal reflex
What is the term used to describe the phenomenon where there is a complete disconnect between the midbrain and pons, resulting in extension of arms and flexion of wrists?
Decerebrate posturing
What is the term used to describe the group of muscles innervated by a single spinal nerve?
Myotome
What is the role of reciprocal inhibition in muscle contraction?
Inhibiting the antagonist muscle
What is the primary function of the rubrospinal tract?
Control of posture and muscle innervation
What do Pacinian corpuscles respond to?
Pressure and vibration
What is the term used to describe the phenomenon where all areas of the brain become active in response to a single painful stimulus?
Pain matrix
What is the function of the medial motor tracts?
Control of posture and muscle innervation
What measures electric activity in muscles, aiding in understanding the location of lesions in the motor nervous system?
Electromyography
What is the primary function of the Golgi tendon organ?
Affecting muscle activation through spinal interneurons
Which reflex coordinates muscle activation in response to a noxious stimulus without the need for cortical input?
Withdrawal reflex
What does electromyography measure in muscles?
Muscle activation
What can be identified through nerve conduction studies?
Nerve damage
Which motor tracts are responsible for controlling posture and muscle innervation?
Medial motor tracts
What do motor neuron lesions result in with needle electromyography?
Heightened muscle activity
What is the primary function of the vertical motor tracts within the spinal cord?
Conveying signals for movement
What is the role of the nonspecific motor tracts, such as the ceruleospinal and raphespinal tracts?
Forming the emotional motor system
What do medial motor tracts primarily innervate?
Axial and girdle musculature
What is the function of the lateral vestibulospinal tract?
Orienting the body towards gravity
Where do signals from the legs primarily travel in the dorsal column-medial lemniscus system?
Lumbar region
What is the basis for regional sensation in the nervous system?
Dorsal column
Where are the cell bodies for the medial corticospinal tract located?
Medial anterior horn of the gray area of the spinal cord
Which tract responds to signals coming from the inner ear, helping orient the body towards gravity?
Lateral Vestibulospinal Tract
What is the primary function of the rubrospinal tract?
Initiating distal limb movement
Which motor tracts arise in the primary motor cortex and supplementary motor area within the cortex?
Medial Motor Tracts
What is the role of the lateral corticospinal tract?
Initiating distal limb movement
What type of motor control is primarily coordinated at the brainstem level?
Automatic motor control
Which tract begins in the reticular formation of the brainstem, sending signals to both ipsilateral and contralateral motor neurons at the spinal level?
Reticulospinal Tract
What does the lateral vestibulospinal tract respond to?
Signals coming from the inner ear
Which tracts are responsible for distal limb movement and fractionation of movements?
Lateral Tracts
Where does the lateral corticospinal tract start?
Premotor cortex
What is the primary role of the medial vestibulospinal tract?
Responding to signals regarding head movement and position
What type of motor system dysfunctions include paresis vs paralysis and abnormal reflexes like Babinski's sign?
Motor System Dysfunctions
Study Notes
Sensory Pathways in the Spinal Cord: Dorsal Column-Medial Lemniscus vs. Anterolateral Column
- Dorsal column-medial lemniscus system conveys high fidelity information on light touch and conscious proprioception
- Signals from lower trunk or legs go to ipsilateral nucleus cuneatus; signals from upper trunk and upper limb go to ipsilateral nucleus gracilis in the lower medulla
- Signals from legs travel up the dorsal column medially in the fasciculus gracilis tract; signals from upper body or arms travel more laterally in the fasciculus cuneatus tracts
- Signals then decussate in the medial lemniscus to target the contralateral VPL nucleus of the thalamus before reaching the contralateral primary somatosensory cortex
- Anterolateral Column contains conscious relay tracts like spinothalamic tract and divergent tracts like spinomesencephalic, spinoreticular, and spino-emotional tracts
- Spinothalamic tract carries information on discriminative pain and temperature; lateral spinothalamic tract carries discriminative pain and temperature, while anterior spinothalamic tract carries crude touch
- Signals travel through dorsal root ganglion to dorsal horn of spinal cord, then to contralateral VPL nucleus of thalamus, and finally to the primary somatosensory cortex on the same side as the VPL nucleus
- Divergent tracts convert pain signals with low fidelity and speed, targeting various areas in the cortex such as prefrontal cortex, parietal vortices, and the insula
- Spinomesencephalic tract targets periaqueductal gray and superior colliculus on the midbrain to draw attention to painful stimulus
- Spinoreticular tract terminates in the reticular formation of the midbrain, interacting with areas responsible for attention, arousal, and sleep-wake cycles
- All three divergent tracts convey signals for slow, vague, pain sensations, targeting various parts of the contralateral brain, thalamus, and midbrain, and traveling up the spinal cord along with the spinothalamic tract
- The spinothalamic tract conveys information on discriminate pain and temperature to the contralateral primary somatosensory cortex, with signals immediately decussating within the spinal cord
Motor Tracts and Dysfunctions in the Spinal Cord
- Medial corticospinal tract primarily innervates axial and girdle musculature, facilitating posture and core strength
- Cell bodies for these tracts are located in the medial anterior horn of the gray area of the spinal cord
- Automatic motor control primarily coordinated at the brainstem level, where these 3 tracts derive
- Reticulospinal Tract begins in the reticular formation of the brainstem, sending signals to both ipsilateral and contralateral motor neurons at the spinal level
- Lateral Vestibulospinal Tract responds to signals coming from the inner ear, helping orient the body towards gravity
- Medial Vestibulospinal Tract responds to signals regarding head movement and position, activating and coordinating muscle activity in the neck and upper back
- Medial Motor Tracts arise in the primary motor cortex and supplementary motor area within the cortex, providing signals for bilateral control of axial and upper girdle muscles
- Lateral Tracts in the spinal cord responsible for distal limb movement and fractionation of movements
- Lateral Corticospinal Tract starts at the premotor cortex, descending downwards through the spinal cord
- Rubrospinal Tract begins at the red nucleus in the midbrain and plays a smaller role than the lateral corticospinal tract
- Motor System Dysfunctions include paresis vs paralysis, abnormal reflexes like Babinski's sign, and phasic stretch hyperreflexia
- Motor System Dysfunctions also include tonic stretch reflex and clonus, which are repeated, involuntary, rhythmic contractions of a single muscle group
Motor System: Spinal Cord and Nerve Assessment
- Type 2 afferent signaling from periphery, interneurons, and motor neurons provides proprioception, informing about the body's position in space and time.
- The Golgi tendon organ informs about tendon tension and lengthening, affecting muscle activation through spinal interneurons.
- A rudimentary stepping pattern is coordinated by a highway of interneurons connecting sensory and motor signals at or near the spinal level.
- Phasic stretch, such as the reflex hammer stretch to the patellar tendon, activates afferent nerves to the spinal cord, initiating a reflex.
- The withdrawal/crossed extension reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input.
- Motor nerve conduction velocity tests locate areas of damage along muscle activation, helping to identify problems in motor nerves, neuromuscular junctions, or muscles.
- Electromyography measures electric activity in muscles, aiding in understanding the location of lesions in the motor nervous system.
- Motor neuron lesions result in heightened muscle activity with needle electromyography, while motor tract lesions may present with degeneration in specific tracts.
- Myopathy, damage to the muscle itself, can be identified through electromyography and nerve conduction studies.
- Vertical motor tracts within the spinal cord convey signals for movement and muscle activation to different parts of the body.
- Medial motor tracts, including the reticulospinal, medial vestibulospinal, and lateral vestibulospinal tracts, are responsible for controlling posture and muscle innervation.
- Nonspecific motor tracts, such as the ceruleospinal and raphespinal tracts, form the emotional motor system, impacting movement in response to emotions.
Motor Tracts and Dysfunctions in the Spinal Cord
- Medial corticospinal tract primarily innervates axial and girdle musculature, facilitating posture and core strength
- Cell bodies for these tracts are located in the medial anterior horn of the gray area of the spinal cord
- Automatic motor control primarily coordinated at the brainstem level, where these 3 tracts derive
- Reticulospinal Tract begins in the reticular formation of the brainstem, sending signals to both ipsilateral and contralateral motor neurons at the spinal level
- Lateral Vestibulospinal Tract responds to signals coming from the inner ear, helping orient the body towards gravity
- Medial Vestibulospinal Tract responds to signals regarding head movement and position, activating and coordinating muscle activity in the neck and upper back
- Medial Motor Tracts arise in the primary motor cortex and supplementary motor area within the cortex, providing signals for bilateral control of axial and upper girdle muscles
- Lateral Tracts in the spinal cord responsible for distal limb movement and fractionation of movements
- Lateral Corticospinal Tract starts at the premotor cortex, descending downwards through the spinal cord
- Rubrospinal Tract begins at the red nucleus in the midbrain and plays a smaller role than the lateral corticospinal tract
- Motor System Dysfunctions include paresis vs paralysis, abnormal reflexes like Babinski's sign, and phasic stretch hyperreflexia
- Motor System Dysfunctions also include tonic stretch reflex and clonus, which are repeated, involuntary, rhythmic contractions of a single muscle group
Motor System: Spinal Cord and Nerve Assessment
- Type 2 afferent signaling from periphery, interneurons, and motor neurons provides proprioception, informing about the body's position in space and time.
- The Golgi tendon organ informs about tendon tension and lengthening, affecting muscle activation through spinal interneurons.
- A rudimentary stepping pattern is coordinated by a highway of interneurons connecting sensory and motor signals at or near the spinal level.
- Phasic stretch, such as the reflex hammer stretch to the patellar tendon, activates afferent nerves to the spinal cord, initiating a reflex.
- The withdrawal/crossed extension reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input.
- Motor nerve conduction velocity tests locate areas of damage along muscle activation, helping to identify problems in motor nerves, neuromuscular junctions, or muscles.
- Electromyography measures electric activity in muscles, aiding in understanding the location of lesions in the motor nervous system.
- Motor neuron lesions result in heightened muscle activity with needle electromyography, while motor tract lesions may present with degeneration in specific tracts.
- Myopathy, damage to the muscle itself, can be identified through electromyography and nerve conduction studies.
- Vertical motor tracts within the spinal cord convey signals for movement and muscle activation to different parts of the body.
- Medial motor tracts, including the reticulospinal, medial vestibulospinal, and lateral vestibulospinal tracts, are responsible for controlling posture and muscle innervation.
- Nonspecific motor tracts, such as the ceruleospinal and raphespinal tracts, form the emotional motor system, impacting movement in response to emotions.
Motor System: Spinal Cord and Nerve Assessment
- Type 2 afferent signaling from periphery, interneurons, and motor neurons provides proprioception, informing about the body's position in space and time.
- The Golgi tendon organ informs about tendon tension and lengthening, affecting muscle activation through spinal interneurons.
- A rudimentary stepping pattern is coordinated by a highway of interneurons connecting sensory and motor signals at or near the spinal level.
- Phasic stretch, such as the reflex hammer stretch to the patellar tendon, activates afferent nerves to the spinal cord, initiating a reflex.
- The withdrawal/crossed extension reflex coordinates muscle activation in response to a noxious stimulus, occurring at multiple spinal levels without the need for cortical input.
- Motor nerve conduction velocity tests locate areas of damage along muscle activation, helping to identify problems in motor nerves, neuromuscular junctions, or muscles.
- Electromyography measures electric activity in muscles, aiding in understanding the location of lesions in the motor nervous system.
- Motor neuron lesions result in heightened muscle activity with needle electromyography, while motor tract lesions may present with degeneration in specific tracts.
- Myopathy, damage to the muscle itself, can be identified through electromyography and nerve conduction studies.
- Vertical motor tracts within the spinal cord convey signals for movement and muscle activation to different parts of the body.
- Medial motor tracts, including the reticulospinal, medial vestibulospinal, and lateral vestibulospinal tracts, are responsible for controlling posture and muscle innervation.
- Nonspecific motor tracts, such as the ceruleospinal and raphespinal tracts, form the emotional motor system, impacting movement in response to emotions.
Motor Tracts and Dysfunctions in the Spinal Cord
- Medial corticospinal tract primarily innervates axial and girdle musculature, facilitating posture and core strength
- Cell bodies for these tracts are located in the medial anterior horn of the gray area of the spinal cord
- Automatic motor control primarily coordinated at the brainstem level, where these 3 tracts derive
- Reticulospinal Tract begins in the reticular formation of the brainstem, sending signals to both ipsilateral and contralateral motor neurons at the spinal level
- Lateral Vestibulospinal Tract responds to signals coming from the inner ear, helping orient the body towards gravity
- Medial Vestibulospinal Tract responds to signals regarding head movement and position, activating and coordinating muscle activity in the neck and upper back
- Medial Motor Tracts arise in the primary motor cortex and supplementary motor area within the cortex, providing signals for bilateral control of axial and upper girdle muscles
- Lateral Tracts in the spinal cord responsible for distal limb movement and fractionation of movements
- Lateral Corticospinal Tract starts at the premotor cortex, descending downwards through the spinal cord
- Rubrospinal Tract begins at the red nucleus in the midbrain and plays a smaller role than the lateral corticospinal tract
- Motor System Dysfunctions include paresis vs paralysis, abnormal reflexes like Babinski's sign, and phasic stretch hyperreflexia
- Motor System Dysfunctions also include tonic stretch reflex and clonus, which are repeated, involuntary, rhythmic contractions of a single muscle group
Test your understanding of sensory pathways in the spinal cord with this quiz. Explore the differences between the dorsal column-medial lemniscus and anterolateral column systems, and grasp their roles in conveying touch, proprioception, and pain signals to the brain.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
