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Sample Autonomic Nervous System Pathways

  • Shown here are examples of visceral or image descriptionautonomic pathways that allow the CNS to regulate blood pressure (BP) and heart rate (HR).
An image showing the autonomic nervous system pathway from the brain to the effective organ passing through the spinal cord, conducting the action potential requires 1 sensory neuron and 3 motor neurons (Upper motor neuron, preganglionic motor neuron and postganglionic motor neuron)
An image showing the autonomic nervous system pathway from the brain to the effective organ passing through the spinal cord, conducting the action potential requires 1 sensory neuron and 3 motor neurons (Upper motor neuron, preganglionic motor neuron and postganglionic motor neuron)
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  • When blood pressure (BP) declines, pressure receptors (baroreceptors) in the wall of the aortic artery image descriptiondetect the change and a corrective, involuntary reflex begins.
  • Action potentials (electro-chemical impulses) are generated in autonomic sensory (afferent) neurons and image descriptionconducted to the cardiac regulatory center in the brainstem.
  • From the brainstem, response impulses are image descriptionconducted down the spinal cord by CNS neurons.
  • These impulses are then transmitted to sympathetic motor neurons (efferent neurons) that originate in the spinal cord. The motor neurons¬† image descriptionconduct the impulses out of the spinal cord sympathetic ganglion located next to the vertebral column. Here, synapses occur and a second set of neurons carry the impulses on to the heart.
  • On their arrival, the impulses stimulate the hear to beat faster and more forcefully.