The Autonomic Nervous System High Yield Notes Exam 3.docx -...

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The Autonomic Nervous System Exam 3The ANS is activated by centers located in: Spinal Cord, Brain Stem, Hypothalamus
The Cerebral Cortex can send a signal to one of these centers to influence actionThe ANS controls most of the visceral (fight or flight) functions of the body:
In 2 seconds, the ANS can induce sweatingIn 2 seconds, the ANS can cause the urinary bladder to empty –involuntarilyIn 3-5 seconds, the ANS can double the heart rateIn 5 seconds, the ANS can REDUCE arterial pressure enough to causefainting (syncope)In 10 seconds, the ANS can double arterial pressureThe ANS is activated by centers located in:Spinal CordBrain StemHypothalamusThe Cerebral Cortex can send a signal to one of these centers to influence actionThe ANS signal may be a visceral reflex at timesIt is these rapid changes that are detected by a polygraph - lie detectorSympathetic nerves are in spinal nerves ((8%) (originate b/w T1-T2))Are NOT skeletal motor nervesThe nerves pass from the cord into one of the sympathetic chain ganglia, then intotissues/organs that are to be stimulatedANS is efferent:Two paravertebral chains of gangliaThese lie to the side of the vertebral column
Two prevertebral gangliaCeliacHypogastricA skeletal neuron in singularEach sympathetic pathway is TWO neurons:- Preganglionic- PostganglionicPreganglionic:Cell body is in the lateral horn of the spinal cordThe nerve fiber passes through the anterior root to the spinal nerveThe preganglionic fibers leave the spinal nerve, and enter a ganglionPostganglionic:Neuron originates in the ganglionSympathetic Chain GangliaPeripheral Sympathetic Ganglia
Sympathetic Chain Ganglia:Once a preganglionic fiber leaves the spinal nerve to enter a ganglion, it has three options:Synapse with a postganglionic fiber;Pass upward or downward then synapse with a postganglionic fiber at a different levelPass through the ganglion and synapse with a fiber in a peripheral sympathetic ganglion.

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Term
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