Circulation, Spinal Cord Flashcards
If pressure becomes elevated in the dural sinuses, blood can shift from the sinuses out to the _____ thus decreasing intracranial sinus pressure
Subgaleal Space
Small vessels that carry blood from the SSS to the subgaleal space
Emissary Veins
Infection or thrombosis in emissary veins and subgaleal space can lead to ___
Dural Sinus Thrombosis»_space; Increased ICP
Choroid plexuses arise from the
pia mater
Symptoms of SAH can mimic
Meningitis - minus the fever
(bc SA space contains CSF)
HA, stiff neck,
_____ wrap around capillaries in brain, adding a second layer of filtration
Astrocytes
+ tight junctions = BBB
Primary regulator for CNS blood flow
Carbon Dioxide
A case where the message goes through the spinal cord and creates effect without involving the brain.
Reflex arc
The motor effects from reflex arcs generally occur before the perception of the event in the higher centers of the brain.
4 neural activities of reflex arch
- Monosynaptic response
(stretch fibers in spindle > spinal cord > muscle) - Reciprocal innervation
(interneuron, inhibits reflex) - Synergistic muscle recruitment
(recruits helper muscles w other monosynaptic) - Ascending information
(up to the boss in higher brain)
Cell bodies for sensory neurons lie
Dorsal Root Ganglia - outside of vertebral canal
Dorsal HORN composed primarily of
sensory interneurons and axons
Ventral horn contains
cell bodies of efferent pathways
Efferent cell bodies leave the spinal cord via
Spinal nerves
These are the neurons that directly synapse with muscles
Lower motor neurons
Destruction of lower motor neurons =
permanent paralysis
___ Neurons w cell bodies in the brain, and axons traveling to appropriate vertebral level to synapse w ___
Upper motor neurons
Lower motor neurons
What neurotransmitter do upper motor neurons use?
GLUTAMATE
doesn’t leave CNS
What neurotransmitter do lower motor neurons use?
Acetylcholine
leaves CNS, goes straight to target
Anterior and lateral spinal cord. Voluntary motion. Motor below the head.
Corticospinal tract
Instructions for movement from Cortex»_space; Spine
**several tracts, rolled together*
Anteriolateral spinal cord. Proprioception, pain, temperature, light touch, pressure
Spinothalamic tract
Perception of temp, pain etc from body > Spin > Thalamus
**Several tracts, all rolled together*
Proprioception, deep touch, vibration. Posterior spinal cord.
Dorsal columns
Afferent, Dorsal Column tract crosses at ___
THE MEDULLA
proprioception, deep touch, vibration
Afferent, Spiniothalamic tract crosses at ___
THE SIGHT OF ENTRY
Descending, Corticospinal tract crosses at ____
THE MEDULLA
Do all nerve fibers of the Corticospinal tract desiccate?
NO - most of them do, but about 10% remain ipsilateral - and innervate very proximal muscles
Syndrome characterized by disproportionally greater motor impairment of the arms than the legs, with variable sensory loss below the level of injury
Central Cord Syndrome
Why are arms affected more than legs in Central Cord Syndrome?
Messages that have to travel the farthest are located most laterally on the spinal cord
medial > lateral = cervical > thoracic > lumbar > sacral
Most common cause of central cord syndrome
Hyperextension of the spinal cord (neck snapped straight back)
Image of spinal cord showing central hemorrhagic necrosis, and swelling is indicative of
Central Cord Syndrome
Variable loss of motor function and perception of temp, pain, light touch - below the site of injury
with preservation of position, vibration, and touch
Anterior Cord Syndrome
Corticospinal and Spinothalamic affected, dorsal columns spared
Cause of anterior spinal cord syndrome?
Hyperflexion
Typically the result of a penetrating injury which has damaged one side of the spinal cord
Brown Sequard Syndrome
Brown Sequard Syndrome characterized by motor loss (corticospinal) and deep touch / vibration / position sensory loss (dorsal) ON THE \_\_\_\_\_ AS LESION
and temp, pain, light touch sensory loss (spinothalamic) ON THE ____ AS LESION
SAME SIDE
OPPOSITE SIDE
Causes of Brown Sequard Syndrome
Penetrating trauma
Ruptured disc
Ischemia (obstruction of spinal vessel)
Infectious/inflammatory disease
Spinal cord tumor
Demyelination of dorsal columns and coritcospinal tracts can be caused by
long term B 12 deficiency
Long term B 12 deficiency that causes demyelination of dorsal columns and coritcospinal tracts is called
Subacute Combined Degeneration
Gradual loss of myelin within the dorsal columns of the spinal cord
Tabes Dorsalis
from tertiary syphilis
Decreased ability to sense proprioception, light touch and vibration below the site of lesion - can be indicative of what?
Dorsal column lesion
ie: Tabes Dorsalis
