Nervous System Functioning - Ch.2

• Central Nervous System (CNS)


  Major division of the nervous system which receives neural messages from and transmits neural messages to the PNS.
• Brain 


  "post office", coordinates information and responds.
• Spinal Cord


  Route for messages to and from the brain.
• Peripheral Nervous System (PNS)


  Major division of the nervous system, the entire nervous system outside the CNS.
• Somatic Nervous System (pSNS)


  A division of the PNS that carries afferent neurons to the CNS and efferent neurons to skeletal muscles.
• Autonomic Nervous System (pANS)


  A division of the PNS that connects CNS to internal organs and glands.
• Skeletal Muscles 


  Muscles connected to the skeleton that carry out voluntary motor movements.
• Visceral Muscles, organs and glands

  Not connected to the skeleton that are predominantly self-regulating and do not require conscious control.
• Sympathetic Nervous System (aSNS)


  A division of the Autonomic NS that responds to danger and/or stressor.
• Parasympathetic Nervous System (aPNS)


  A division of the autonomic NS that brings the body down to main tain the body to its normal state (homeostasis)
• Neuron 


  A nerve cell that transmits and receives neural information.
• Efferent Neurons


  Motor Movement from CNS to PNS
• Afferent Neurons


  Sensory stimuli from PNS to CNS.
• Interneurons 


  Neurons that make up efferent and afferent neurons.
• Conscious Response 


  A deliberate and voluntary action that is initiated by the brain and performed intentionally by the body.
• Sensory Receptor


  A nerve ending that detects internal sensations in the body and external sensations from the environment.
• Unconscious Response

  An automatic and involuntary actions that is performed by the body.
• Spinal Reflex


  An unconscious response to sensory stimuli that is initiated by interneurons in the spinal cord.
• Reflex Arc


  The path along which the neural signal is transmitted as a part of the spinal reflex.
• Neural Synapse


  The region where two neurons meet.
• Presynaptic Neuron


  Releases neurochemicals into the synapse.
• Axon Terminal


  End of neurons that release neurochemicals.
• Synaptic Gap


  Space between the presynaptic and postsynaptic neurons.
• Postsynaptic Neuron 


  Receives the neurochemicals from the presynaptic neuron.
• Dendrite


  Branched extension where receptors sites are located.
• Neurochemicals 


  Chemicals substances that transmits neural information within the nervous system.
• Neurotransmitter


  Chemical molecule that has an effect on one or two postsynaptic neurons.
• Glutamate 


  Main excitatory neurotransmitter, plays a role in learning and memory, and enable synaptic plasticity.
• Gamma Amino Butyric Acid (GAMA)


  Main inhibitory neurotransmitter, prevents over excitation and reduces anxiety as well as an important role in preventing seizures.
• Action Potential


  Electrical impulse that travels down the Axon.
• Excitatory Effect


  increases the likelihood of the postsynaptic neuron firing an action potential.
• Inhibitory Effect


  Decreases the likelihood of the postsynaptic neuron from fring an action potential.
• Neuromodulator 


  Chemical molecule that has an effect on multiple postsynaptic neurons.
• Dopamine

  Voluntary motor movement, experiences of pleasure and reward-based learning. Can have both an inhibitory and excitatory effect, based on receptor site.
• Serotonin


  Responsible for regulation of mood and sleep. Has an inhibitory effect on postsynaptic neurons.
• Synaptic Plasticity


  The ability of synaptic connections to change over time in response to activity or experience.
• Sprouting 


  The ability of dendrites or axons to develop new extensions or branches.
• Rerouting


  The ability of a neuron that is connected to a damaged neuron to create an alternative connection with an undamaged neuron.
• Pruning


  The elimination of neurons and synapses that are not activated enough. "use it or lose it"
• Learning


  The process of acquiring knowledge, skills or behaviours from experience.