Psychology / Unit 2: The Brain and Behavior
2.3 The Nervous System
Notes
The nervous system is the body's communication network.
- Central nervous system (CNS): the brain and spinal cord.
- Peripheral nervous system (PNS): nerves connecting the CNS to the rest of the body.
- The PNS has a somatic division (voluntary skeletal muscles) and an autonomic division (automatic body functions).
- Autonomic: the sympathetic system is "fight or flight" (raises heart rate, speeds breathing); the parasympathetic system is "rest and digest" (calms the body).
- Three neuron types: sensory (to the CNS), motor (from the CNS), interneurons (connect them inside the CNS).
- A reflex is a fast automatic response handled by the spinal cord.
Practice
A student hears a loud bang and her heart starts to pound. Which system caused this?
The sympathetic system prepares the body for action.
Which neurons carry messages from the brain and spinal cord to muscles?
Motor neurons carry commands out to muscles and glands.
The central nervous system consists of:
The CNS is the brain and spinal cord only.
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