Bales: spinal cord topography Flashcards Preview

neuro exam 1 > Bales: spinal cord topography > Flashcards

Flashcards in Bales: spinal cord topography Deck (19):

What is hydromyelia and what symptoms can it lead to?

Abnormal enlargement of the central canal is hydromyelia, a subset of spinal cord diseases called syringomyelias (fluid-filled cavity in the cord)

The pressure caused can produce both motor and sensory problems by compression of adjacent tracts (nerves don't like to be compressed)

Spinal cord itself does not necessarily expand.


What is the dorsal column of the spinal cord's function? How many columns are in the spinal cord at different levels?

The dorsal column is entirely sensory

From sacral to mid-thoracic level (~T6), the dorsal column is only 1 fasciculus (gracilis)

From mid-thoracic through cervical levels, dorsal column is 2 fasciculi (gracilis (more medial) + cuneatus (lateral))


Where is the fasciculus proprius? and what is its function?

A shell (veneer) of white matter bordering the gray matter in all 3 columns is a specialized tract for conveying fibers between cord levels (“proprio-” = self or within)


What are the laminae components of the dorsal horn of the spinal cord?

I=marginal zone (tip)
II=substantia gelatinosa
III, IV=nucleus proprius

ALL are sensory


Which lamina is between dorsal and ventral horns? What is it continuous with? What are some subregions of VII at levels T1-L2?


it is continuous with X (gray commissure)

from T1-L2: VII includes intermediolateral cell column (preganglionic sympathetic fibers) and clarke's nucleus (proprioceptive relay nucleus)


What laminae are the motor system cell columns?


Lamina VIII contains interneurons which integrate motor inputs and synapse on motor neurons
The somatic efferent motor neurons (α & γ) are in lamina IX (discontinuous)


What levels of the spinal cord are enlarged and why?

ventral horns of:
C5-T1--> brachial plexus

L4-S4--> lumbosacral plexus


How many anterior spinal arteries does the spinal cord have? What does it supply blood to? What will arise from an anterior spinal A hemorrhage or occlusion?

one (from combining branches of the 2 vertebral arteries)

anterior spinal a. usually supplies bilaterally:
anterior column, ventral horn, commissures, intermediate horn, and adjacent lateral column

A hemorrhage or occlusion will cause paralysis due to the ventral horn's loss of blood supply


What will be the result of a lesion (hemorrhage/occlusion) of the anterior spinal a. at the level C3-5?

diaphragm paralysis


What will be the result of a lesion of the anterior spinal a. at the level C5-T1

paralysis of upper limb


What will be the result of a lesion of the anterior spinal a. at the level T1-T3?

interrupts sympathetics to the head (Horner's syndrome)


What will be the result of a lesion of the anterior spinal a. at the level L4-S1?

paralysis of lower limbs


What will be the result of a lesion of the anterior spinal a. at the level S2--S4?

disrupts bladder function, sexual function, and bladder & bowel continence (intermediate horn & Onuf's nuc.)


What supplies blood to the posterior 1/3 of the spinal cord? What does this posterior 1/3 include?

Posterior spinal aa. (2) supply the posterior 1/3 (branch from PICA)

dorsal columns, dorsal horns, dorsal parts of the lateral columns


What will an upper cervical lesion of the posterior spinal a. lead to?

Because of a the cumulative nature of the dorsal column, an upper cervical lesion will cause loss of senses in lower and upper limbs


What will a lumbar lesion of the posterior spinal a. lead to?

Since only fasciculus gracilis is present, a lesion at the level will cause loss of senses from lower limb


What does arterial vasocorona supply blood to? What will happen from a lesion here?

Penetrating brs. from the arterial vasocorona supply the peripheral marginal area

A compromised vasocorona would al least effect proprioceptive functions (balance, coordination, and position sense), and possibly pain & temperature


What is the difference between myelopathy, radiculopathy and neuropathy?

Myelopathy refers to spinal cord lesions.

Radiculopathy refers to spinal nerve root lesions

Neuropathy refers to peripheral disease and includes plexopathies and mononeuropathies.


What is non-traumatic (surfer's) myelopathy?

results from prolonged hyperextension of the thoracic region of surfers

Includes lower limb paresis-paralysis, sensory disturbance, and urinary retention

Possible contributing factors include the narrowness of the vertebral canal in the thoracic region and paucity of segmental arterial input in the thoracic region