Intro to Nervous System & Spinal Cord

regulate concentrations of ions and NTs in the extracellular space near neurons, regulate synaptogenesis

immune system in the CNS

1) binding to transmitter transport sites (large capacity, very fast)
2)reuptake via transport sites into presynaptic terminal (fast)
or uptake into astroglia (medium fast)
3) metabolism to an inactive molecule (slow)
4) diffusion (slow)

gray matter divided such that higher numbers are assigned to more ventral lamina.
Lamina I = marginal nucleus
Lamina II = substantia gelatinosa
Lamina VII = intermediate gray
Lamina VIII and IX = motor neurons

Dorsal column -> proprioception; axons terminate in the ipsilateral lower medulla

Spinothalamic tract -> pain and temperature sensation , axons terminate in the contralateral thalamus

corticospinal tract/pyramidal tract - voluntary skilled control of distal musculature; cell bodies of origin at the cerebral cortex, terminates on contralateral motor neurons

1) sensory level
2) less pronounced motor lever
3) disturbance in voluntary control of bowel and bladder

arises from vertebral arteries at medulla, unpaired, medullary branches serve up to 2/3 of the cord volume

arises from vertebral or sometimes the PICA at the level of the medulla

small anastomosing arteries between anterior and posterior spinal arteries; serve the superficial anterior and lateral white matter.

the cervical portion of the cord via the spinal branches. radicular arteries help to supply blood to the rest of the cord

arises from a left intersegmental branch of the descending aorta ; reaches cord at lower thoracic or upper lumbar levels

ischemia bc it is sparsely served by radicular arteries