Pathways Flashcards
Spinothalamic
Pain, temperature, crude touch from body
Trigeminothalamic
Pain, temperature, crude touch from face
Discriminative touch, conscious proprioception from face
Dorsal column-medial lemniscus system (DCML)
Discriminative touch, conscious proprioception from body
Dorsal spinocerebellar/cuneocerebellar
Nonconscious proprioception
Ventral spinocerebellar
Nonconscious proprioception
Corticospinal
Voluntary motor to body
Corticobulbar
Voluntary motor to head
Cerebellum, Basal ganglia
Adjustment, fine-tuning systems
Location of neurons of Spinothalamic tract
Neuron 1:
Neuron 2:
Neuron 3:
1: DRG
2: Spinal cord (dorsal horn) –> axon decussates
3: Thalamus
Lesion here results in loss/decrease of pain and temperature sensation
Spinothalamic tract
Location of neurons of DCML
Neuron 1:
Neuron 2:
Neuron 3:
1: DRG
2: Medulla –> axons cross medulla –> ascend in contralateral medial lemniscus
3: Thalamus
Lesion of this pathway lead to loss of diminution of 2 point discrimination, vibration sense, limb position sense, kinesthesia
DCML
Information in spinocerebellar tracts mostly comes from ____ and ____.
muscle spindles
Golgi tendon organs
Signals ascend to ___ in spinocerebellar tracts.
Cerebellum
Lesions of spinocerebellar pathways
Do not usually produce obvious signs
Lateropulsion can occur during lesions of
Spinocerebellar pathways
Two components of corticobulbospinal tract
Corticospinal system
Corticobulbar system
2-neuron pathway
Corticobulbospinal system
The majority of corticospinal fibers cross in ___ to form the ____. They descend in the _____, and synapse on _____ in ____ .
Pyramidal decussation of lower medulla Lateral corticospinal tract Lateral funiculus LMN Ventral horn at every level of spinal cord
Uncrossed corticospinal fibers form ____ and descend in the ___. They cross in the ____ to synapse on ____ in the _____.
Anterior corticospinal tract Ventral funiculus Ventral white commissure of the spinal cord LMN contralateral ventral horn
____ results from loss of inhibition of stretch reflex which normally maintains ____
Hypertonia
Muscle tone
____ results from loss of inhibition of the lower motor neuron
Exaggerated deep tendon reflexes
All motor pathways from all levels of the motor system eventually converge on ____
Lower motor neurons
Lesions of LMNs causes ____
loss of signals to generate muscle contraction and neurotrophic input
Causes weakness/paressi/paralysis
Lesions to LMNs
Causes decreased/abolished deep tendon reflexes
Lesions to LMNs
Causes muscle atrophy and fasciculation
Lesions to LMNs
Causes hypotonia
(Flaccidity)
Lesions to LMNs
____ provides error correction for motor system
Cerebellum
____ allows for learning of complex motor tasks
Basal ganglia
____ are first order neurons in the somatosensory pathway.
Dorsal root ganglion neurons
