Name That Tract
Responsible for volitional movement
Corticospinal (pyramidal) tract
What innervates the intrafusal muscle fiber that keeps us tense and ready to catch ourselves?
gamma
Where axons from primary motor cortex run through in the beginning of the corticospinal, corticobulbar, and reticulospinal tracts
Internal capsule
If there is a lesion to the corticospinal tract above the pyramidal decussation, the ___ side of the body will be effected
Opposite
Patient presents with eye and mouth facial droop on right side of the face. What structure was effected?
Right facial nerve
Tract travels through anterior funinculus of the spinal cord and synapses on only the alpha motor neuron it wants to act on (makes up 10% of fibers)
What tracts are mainly responsible for monitoring and modifying our tone?
Extrapyramidal tracts
The extensor facilitatory center is located in the ___ and the flexor facilitatory center is located in the ___
pontine reticular nucleus, medullary reticular nucleus
Damage to the alpha motor neuron would be considered a ___ lesion
Lower motor neuron
Patient has right hemiparesis, a right lower facial droop, and hyperreflexia. Where could the lesion have been?
lesion to corticospinal and corticobulbar tract in the left internal capsule
Damage to one side of this tract will not result in impairments
Corticobulbar tract
What is postural tone?
Activity in muscles that counteract force of gravity in upright position
The nuclei in the corticobulbar tract that are the exception of the "insurance policy".
Facial nuclei
If there is a lesion to the right internal capsule, the impairments will be where on the face?
Left lower face (droop)
Patient presents rigid in extension in both the upper and lower extremities. Where could the lesion have been?
Decerebrate posture from damage below the red nucleus
Directs head movements in response to auditory and visual stimuli
Tectospinal Tract
This tract will give us the tone we need to keep our head stable while walking and upright against gravity
Medial Vestibulospinal tract
The structure in the midbrain that the corticospinal tract passes through (be specific!)
Middle 2/3 of cerebral peduncles
If there is a lesion above the red nucleus, what tract(s) are going to dominate?
Vestibulospinal and rubrospinal
Patient presents with a FOOSH injury to their right wrist and informs you they slipped and fell backwards on ice yesterday. What tract was at work when they fell?
Lateral Vestibulospinal Tract
Facilitates flexion and travels in the anterior funinculus to activate both alphas and gammas at the level it wants to act on
Lateral reticulospinal tract
Tone is maintained by the __________ Principle
Alpha-Gamma Coactivation Principle
The zone of the reticular formation that will send information either up to the cortex to keep us awake or down as the reticulospinal tract.
Paired medial zone
If there is a lesion to the left upper cervical anterior horn, where would volitional motor deficits be in the body?
Left side of the body
Patient presents with decorticate posture. Where do you think their lesion was?
Above the red nucleus: flexion of UE from rubrospinal and extension of LE from vestibulospinal