GS - Structure and Function of Spinal Cord Flashcards
Where are the 2 spine enlargements?
Cervical (C4 - T1)
Lumbosacral (L2-S3)
Due to arms and leg nerves branching off
Which vertebral level does the spinal cord end in an adult?
L1-L2
At which level would you sample CSF by lumbar puncture and how would you identify this practically ?
L3 - 4 space
or
L4 - 5 space
Palpating the right and left posterior superior iliac crests and moving the fingers medially toward the spine
Palpate that interspace (L3-L4), the interspace above (L2-L3), and the interspace below (L4-L5) to find the widest space
How does the cross section of the spinal cord change ?
Bulges due to limb grey matter (cervical, lumbosacral)
White matter increases up cord (accumulated neuronal traffic to and from brain)
In this HISTOLOGICAL VIEW of the spinal cord label the right side (with an R) and the dorsal aspect (with a D)
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Label this cross section
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Put these sections in order from rostral to caudal ?
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What pathways is this?
Anterolateral pathway
What pathways is this?
Dorsal column pathway
What pathways is this?
Corticospinal tract
What type of information do the gracile and cuneate tracts carry?
Conscious proprioception, vibration, light touch
Where does the dorsal column pathway cross the midline?
Medulla
What information does the anterolateral (also known as spinothalamic) pathway carry?
Pain, temperature, itch, touch
Where does the anterolateral (also known as spinothalamic) pathway cross over the midline?
Spinal cord at or near the level of entry
What type of information to spinocerebellar tracts carry ?
Unconcious proprioception
Where does the spinocerebellar cross the midline?
Dont cross!
What information does the corticospinal tract carry ?
Motor from cerebral cortex
Where does the corticospinal tract cross over the midline?
Medulla and spinal cord
What is Brown-Séquard Syndrome and what does it affect ?
Brown-Séquard syndrome is caused by damage to one half of the spinal cord, i.e. hemisection of the spinal cord
Results in paralysis and loss of proprioception on the same (or ipsilateral) side as the injury or lesion, and loss of pain and temperature sensation on the opposite (or contralateral) side as the lesion.
How is the spinal cord supplied with blood?
Posterior spinal arteries;
From the cerebral arteries and posterior inferior cerebellar arteries. These arteries are paired.
Anterior spinal artery;
From the vertebral arteries
Segmental arteries;
From the vertebral arteries, cervical arteries, lumbar arteries
Medullary arteries;
Can anastomose with anterior spinal artery
And 1 more special artery ….
What is the special artery that supplies the spinal cord at level 9th to 12th intercostal?
Artery of Adamkiewicz;
Typically arises from left posterior intercostal artery at the level of the 9th to 12th intercostal artery, which branch from the aorta, and supplies the lower two thirds of the spinal cord via the anterior spinal artery
Careful manipulation of aorta during surgical procedures, between segments which give off branches of 9th to 12th intercostal artery, to prevent blockage of the artery of Adamkiewicz
What is anterior cord syndrome and what does it cause?
Where the anterior spinal artery is blocked.
Causes a loss of all motor control below lesion as well as the loss of pain and temperature at and below the level of the lesion
What is central cord syndrome/Sphingomyelia and what does it cause?
The syndrome disproportionately affects the spinothalamic (pain and temperature) and corticospinal (motor) tracts, both located in the anterior two-thirds of the human spinal cord, while typically sparing the posterior columns (light touch and proprioception).
What information does the Rubrospinal tract carry and where does it fibres cross the midline?
The Rubrospinal tract controls muscle tone in flexor muscle groups (it is particularly important in the term newborn because of the flexor tone in the limbs).
Rubrospinal fibers cross in the ventral tegmental decussation of the midbrain
Rubrospinal tract is a descending pathway, beginning as axons of the neurons present in the red nucleus and terminates by synapsing with the interneurons in the spinal cord. It is part of the extrapyramidal system and is important for regulating the activity of the motor neurons.
What information does the Reticulospinal tract carry and where does it fibres cross the midline?
Reticulospinal tract carries information or orders from the reticular formation in the brainstem to the peripheral body part
Dosent cross, is ipsilateral
What information does the Vestibulospinal tract carry and where does it fibres cross the midline?
Vestibulospinal tract maintains equilibratory reflexes from the input of the vestibular apparatus (e.g if falling medial for head to go back, lateral for arms to go out)
Doesn’t cross, ipsilateral
What information does the Spinocerebellar tract carry and where does it fibres cross the midline?
The spinocerebellar tracts carry unconscious proprioceptive information gleaned from muscle spindles, Golgi tendon organs, and joint capsules to the cerebellum.
Rostral pons/caudal midbrain is where the tract crosses the midline again to enter the cerebellum through the superior cerebellar peduncle.
What is the correct order in cervical to sacral direction?
B, A, C
A patient has a bilateral loss of pain and temperature and atrophy of muscles in both hands. Conscious proprioception is conserved. What is the most likely cause?
Sphingomyelia
What is the function of the lateral corticospinal tract in the spinal cord ?
Controls fine flexor movement
In which region of the spinal cord would you find this slice?
Thoracic as limbs are other 3
