Flashcards in Basic Sensory/Motor tracts Deck (20):
What type of reflex is involved in the jaw-jerk and patellar reflexes?
Myotatic reflex (monosynaptic)
Main features of a secondary neuron in a conscious sensory pathway?
Decussates, and ascends as a lemniscus -> terminates on tertiary neuron in dorsal thalamus
LMNs originate where in the spinal cord?
Anterior horn cells
UMNs forms what tract after they decussate?
Lateral Corticospinal tract (decussate at pyramids)-> terminate in LMN pols
What are the posterior columns responsible for?
Proprioception and 2-point tactile discrimination
The dorsal column/medial lemniscal system carries what kind of information?
Proprioception, 2-point tactile discrimination, vibratory and pressure sensations
What carries proprioceptive/2-pt tactile input to UE, and LE, respectively?
fasciculus cuneatus and fasciculus gracilis
What type of lesion causes a positive Babinski sign?
What pathway is responsible for fast pain?
Lateral Spinothalamic tract- Sharp, localized pain/temp sensation
Contralateral loss of pain/temp sensation 2 sensory dermatomes below lesion indicates what?
Lateral spinothalamic tract lesion
Brown-Sequard syndrome is what? Sx?
Hemisection of spinal cord. Results in ipsilateral loss of proprioception/2-pt tactile (posterior columns), ipsilateral spastic paralysis (motor tracts) and contralateral loss of pain/temp sensation 2 sensory dermatomes below lesion (LSTT)
Destruction of the anterior white commissure results in what?
B/L loss of pain/temp sensation to UE (yolk-like anesthesia)
What makes up the spinal lemniscus?
VSTT (crude tactile) and LSTT (Fast pain/temp)
Where do the superior sagittal venous sinus and straight sinuses drain into?
Superior sagittal-> R transverse sinus
Straight sinus-> L transverse sinus
What cranial nerves are responsible for taste?
Anterior 2/3= CN5
Posterior 1/3= CN9
All U/L lesions of the lateral spinothalamic tract result in what?
Contralateral loss of pain/temp 1-2 segments below lesion
What would a U/L lesion of the Spinal lemniscus result in?
Contralateral loss of pain/temp from the body
What would a U/L lesion of the medial lemniscus result in?
Contralateral loss of proprioception/2-point tactile discrimination from the body. (remember- lemniscus is in brainstem)
Where does the corticospinal tract decussate?
At the pyramids (contralateral hemiplegia if injured above them)