Spinal Cord Processing of Sensory Input and Motor Output

Step #1

sensory receptors detect a sensory stimulus

Step #2

sensory neurons convey sensory input impulses along their axons

• sensory receptor-peripheral

• nerve-spinal

• nerve-posterior

• nerve root/rootlets-posterior grey horn

  • axons → along paths of Step 3, 4, or 5

Step #3

sensory axons pass through the posterior grey horn into the white mater and ascend to the brain as part of a sensory tract

Step #4

sensory axons synapse with interneurons in the posterior grey horn whose axons enter white mater and ascend to the brain as part of a sensory tract

Step #5

sensory axons synapse with interneurons in the posterior grey horn that in turn synapse with somatic motor neurons of the anterior grey horn (spinal reflex pathways)

Step #6

axons carry impulses from the brain down motor tracts in the white mater to the anterior grey horn where they synapse with somatic motor neurons

Step #8

autonomic motor neurons convey motor output to cardiac muscle, smooth muscle, and glands

Step #9

axons of autonomic motor neurons from spinal crod synapse with another group of autonomic motor neurons in the PNS which in turn synapse with autonomic effectors