The Major Systemic Veins
Sample Somatic Nervous System Pathways
- Pain signals are delivered to the brain by a route that involves two nervous system (NS) pathways. The first is a somatic NS pathway and the second is a central NS pathway.
- When the skin is penetrated by a sharp object such as a tack, the resulting damage is detected by pain receptors (or nociceptors).
- Electrochemical impulses (or actions potentials) are generated in somatic sensory neurons and conducted into the CNS.
- Another set of neurons carry the information up the central nervous system to the cerebral cortex, where the pain is imaged and interpreted.
- Conscious (or voluntary) response activities also involve two pathways. The first is a central NS pathway and the second is a somatic NS pathway.
- After stimuli (such as pain) are processed in the brain, other neurons plan adjustment responses (to remove the tack).
- Implementation of a (pain) response begins when CNS neurons conduct impulses from the cerebral cortex to the spinal cord.
- In the spinal cord, the impulses are transmitted to somatic motor neurons, which carry them out to the skeletal muscles (needed to remove the tack).