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Peripheral Nervous System (PNS)
connects the brain and spinal cord to the rest of the body
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Two Parts of the peripheral nervous system
- Somatic Nervous System
- Autonomic Nervous System
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Somatic Nervous System
consists of axons conveying messages from the sense organs to the CNS and from the CNS to the muscles
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Autonomic Nervous System
sends and receives messages to regulate the automatic behaviors of the body (heart rate, blood pressure, digestion, etc.)
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Two Parts of the Autonomic Nervous System
- Sympathetic Nervous System
- Parasympathetic Nervous System
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Sympathetic Nervous System
- network of nerves that perpares the organs for rigorous activity
- Increases heart rate, blood pressure, respiration, etc. (fight or flight response)
- Comprised of ganglia on the left and right of the spinal cord
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Parasympathetic Nervous System
- facilitates vegetative, nonemergency response
- decreases functions increased by sympathetic nervous system
- comprised of long preganglion axons extending from the spinal cord and short postganglionic fibers that attach to the organs themselves
- Dominant during relaxed states
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Postganglionic axons of the parasympathetic nervous system mostly release _____ as a neurotransmitter
Acetylcholine (Ach)
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