11 Spinal Cord Flashcards Preview

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Flashcards in 11 Spinal Cord Deck (28):

Descending tract
Moves the muscles of the extremities
Managed by basal ganglia and coordinated by the cerebellum

Corticospinal tract


Ascending tract
Medial lemniscal pathway

Dorsal column


Carries majority of information of localized sensations of the fine touch, proprioception and visceral pain

Medial lemniscal pathway


Ascending tract
Transmits pain and temperature sensations to the thalamus

Spinothalamic tract


Motor and descending (efferent) pathways

Pyramidal tracts (lateral corticospinal tract, anterior corticospinal tract)
Extrapyramidal tracts (rubrospinal tract, reticulospinal tract, vestibulospinal tract, olivospinal tract)


Sensory and ascending (afferent) pathways

Dorsal column medial lemniscus system (gracile fasciculus, cuneate fasciculus)
Spinocerebellar tracts (posterior spinocerebellar tract, anterior spinocerebellar tract)
Anterolateral system (lateral spinothalamic tract, anterior spinothalamic tract)
Spino-olivary fibers


Touch pathway located on the dorsal column of the spinal cord

Dorsal column pathway


Extends from C3 to T2 verebra
Maximum circumference is at the level of exit of the C6 spinal nerve
Reflects increased input and output from and to the upper extremities

Cervical enlargement


Only one artery that supplies the anterior 2/3, the anterior spinal artery, which includes the anterior horn involved in motor function

Thoracic watershed


Arise above from the PICA's and below from segmental arterial supply
Supplies posterior 1/3

Paired posterior spinal arteries


Arises from fusion of spinal branches of the vertebral arteries and descends continously, depending heavily on radicular arterial supply

Single anterior spinal artery


Supply the spinal cord from C8 to T9, involutes in adulthood

Paired small radicular arteries


Rest of the spinal cord is supplied by the ____

Artery of Adamkiewicz


Lower extremity
Starts at the level of T9
Comprised of L2 to S4 segments

Lumbar enlargement


Tail of the spinal cord
T11-12 vertebral level
Lesions present as UMN with some LMN involvement



Anywhere above the anterior horn cells

Upper motor neuron


From the anterior horn to spinal nerves

Lower motor neuron


Anterior horns are no longer seen, just the tail ends
All peripheral nerves
L1/L2 vertebral level
Lesions are combined UMN and LMN, with preserved knee jerk but absent ankle reflexes

Conus medullaris


Approximately 10 fiber pairs
Purely peripheral nerves
Lower motor neurons
Compression or metastasis results in lower motor neuron deficiencies

Cauda equina or horse's tail


Sensory fibers will end up on ____, to hit on another neuron, which is destined to send its fibers to the hypothalamus

Dorsal horn


Once the second neuron is activated, the axons of sensory fibers will cross in the _____

Spinothalamic tract


Corticospinal tract will cross in the ____

Cervicomedullary junction


The lesion interrupts fibers crossing to enter the spinothalamic tracts, and fibers mediating the tendon stretch reflex. As it enlarges, it affects the inferomediolateral columns and the lateral corticospinal tracts

Central cord syndrome


Damage in the corticospinal tract, which is already crossed, same arm and leg is paralyzed. When the dorsal column pathway, which hasn't crossed yet is hit, numbness will be on the same side. Loss of pain sensation will be opposite the side of the spinal cord affected. Loss of motor movement will be on the same side. Loss of light touch will also be on the same side

Brown-Sequard syndrome (hemicord syndrome)


Conducts impulses from receptors of the skin and from the proprioceptors to the spinal cords or brainstem, where they synapse with second order neurons
Starts at the cerebral cortex in the somatomotor area

First order neuron of the descending tracts


Carries an order that could be either a sensory stimulus or a motor stimulus

Second order neuron of the descending tract


Located in the ventral horn of the spinal cord, which will exit with the spinal nerve to supply the muscle

Third order neuron of the descending tract


Arise from long axons of the pyramidal cells of the precentral gryus

Corticospinal tract