Definitions-2 Flashcards
What are the nuclear tracts that modulate postural stability ?
Vestibulospinal Reticulospinal Rubiospinal tectospinal **These tracts originate in the brain stem and target LMN in the spinal cord
What is the origin and target of the Lateral Corticospinal Tract ?
The Lateral corticospinal tract originates in the cortex and synapses on the LMN. It crosses over at the pyramidal decussation in the caudal medulla.
What is the purpose of the lateral corticospinal tract ?
Skilled voluntary movements of the distal extremities
What is the origin and target of the Anterior corticospinal Tract? include cross overs
The Anterior CST. Begins in the cortex and synapses in the LMN. The tract crosses over at the level of the LMN.
What is the purpose of the Anterior CST ?
It is responsible for postural adjustments that accompany voluntary movement
What is the origin and target of the corticobulbular spinal tract ?
Primary motor cortex and targets the LMN in brain stem nuclei. The cross over is mostly bilateral
What is the function of the corticobulbular tract ?
Voluntary movement of the head and neck
What is the origin and target of the vestibulospinal tract.
Medial vestibular nuclei and synapses in the LMN. It crosses the midline bilateral to the neck muscles and regulates postural adjustments.
What is the origin and target of the Lateral vestibulospinal tract? include cross overs
Lateral Vestibulospinal nuclei and synapses in the LMN of the spinal cord. This tract is ipsilateral. It mediates the flexor function and inhibits extensors as well as mediates postural adjustments and changes in balance.
What is the origin and target of the reticulospinal tract ?
It originates in the reticular formation and targets the LMN in the spinal cord. This tract is mostly ipsilateral with some bilateral projections. This tract modulates changes in muscle tome associated with voluntary movement and postural stability
What is the origin, target, and significant cross overs of the Rubospinal tract
The rubospinal tract originates in the red nucleus and targets the LMN in the spinal cord. It crosses over in the midbrain. It modulates flexor movements in the upper limb.
What is the origin and target of the tectospinal tract?
The tectospinal tract originates in the superior colliculus and targets the LMN in the cervical spinal cord. This tract is bilateral. This tract orients the neck in response to eye movements.
Where does the lateral corticospinal tract cross the midline ?
At the pyramidal desiccation
Where does the anterior corticospinal tract cross the midline ?
It descends ipsilaterally and crosses over at the level in which it terminates.
At what level does the lateral corticospinal tract cease to innervate the body ?
Below L2 the only innervation to the LMN is the lateral corticospinal tract.
In a nut shell what is the purpose of the anterior corticospinal tract ?
It allows the CNS to modulate ipsilateral postural tone to accommodate contralateral limb movement.
What are the two main functions of the reticular spinal tract ?
Control of breathing and the emotional motor system.
How does the reticular system modulate the emotional posture changes ?
Through the monoaminergic neurotransmitters and the limbic system.
What motor tract mediates the activity of the extensor muscles and mediates postural adjustments for changes in the position of the head?
Lateral vestibulospinal tract.
How are the medial and lateral vestibulospinal tracts different.
The lateral vestibulospinal tract is responsible for maintaining posture and balance during changes in body position. It also facilitates the activity of extensor muscles and inhibits flexors.
Origin of the reticulospinal tract ?
Pontine and rostral medulla. The tract then descends ipsilaterally in the anteromedial area of the brainstem and the anterior white column of the spinal cord and terminates on LMN circuits throughout the length of the spinal cord.
What will compression of the left cerebellar peduncle cause ?
It will cause decreased muscle tone and lowered reflexes on the right side. The crossover in the pyramidal decussate is caudal to this point.
What are the functions of the reticular spinal tract ?
It integrates distal and proximal muscle actions and initiates and changes tone related to voluntary movement of the limbs.
It regulates primitive motor behaviors such as orientation of the body toward or away from a stimulus.
Controls breathing and activates muscles responsible for respiration.
Integrates the monoaminergic neurotransmitters and the limbic system to control the emotional motor system.
What are the main functions of the rubrospinal tract ?
This tract originates at the red nucleus in the mid brain and is responsible for flexion of the upper limb.
What is the function of the Tectospinal tract ?
It is responsible for innervating the muscles responsible for neck movements. This tract also orients the head and neck during eye movements.
Origin of the tectospinal tract ?
Superior colliculus of the mid brain
Origin of the rubrospinal tract ?
Red nucleus of the mid brain
Origin of the reticulospinal tract ?
Originates in the pontine and rostral medullary reticular formation. Then it descends ipsilaterally in the antermedial area of the brain stem and the anterior white column of the spinal cord.
What is the general rule for somatotrophic organization in the central nervous system
The arms are medial to the legs with two exceptions: The primary sensorimotor cortices and the posterior columns.
UMN Lesion
Upper Motor Neuron Lesions will present with weakness with increased tone and hyper-reflexia with a positive babinski, or Hoffmans sign, posturing
The patient will not have atrophy or fasiculations
What are the signs of a LMN lesion ?
A LMN lesion will present with weakness, atrophy, decreased tone, hyporeflexia, and fascinations.
What does paresis mean ?
Weakness
What does the prefix Hemi- mean ?
One side of the body
