Psych

• Nervous system


  An extensive network of specialized cells that carry information to and from all parts of the body

  
• Neuroscience


  Deals with the structure and function of neurons, nerves, and nervous tissue, and their relationship to behavior and learning
• Neuron


  The basic cell that makes up the nervous system and receives and sends messages within that system
• Parts of a neuron

  • Dendrites
  • Soma
  • Axon
• Dendrites


  Branch-like structures that receive messages from other neurons
• Soma


  The cell body of the neuron, responsible for maintaining the life of the cell
• Axon


  Long, tube-like structure that carries the neural message to other cells
• Glial cells


  • Provide support for the neurons to grow on and around
  • Deliver nutrients to neurons
  • Produce myelin to coat axons
  • Clean up waste products and dead neurons
• Myelin


  Fatty substances produced by certain glial cells that coat the axons of neurons to insulate, protect, and speed up the neural impulse
• Ions


  Charged particles, with the inside of the neuron being negatively charged and the outside being positively charged
• Resting potential


  The state of the neuron when not firing a neural impulse
• Action potential


  The release of the neural impulse consisting of a reversal of the electrical charge within the axon, allowing positive sodium ions to enter the cell
• A neuron either fires completely or does not fire at all (all-or-none)
• Axon terminals


  Rounded areas at the end of the branches at the end of the axon, responsible for communicating with other nerve cells
• Synaptic vesicles


  Sack-like structures found inside the axon terminal containing neurotransmitters
• Neurotransmitter


  Chemical found in the synaptic vesicles which, when released, has an effect on the next cell
• Synapse/synaptic gap


  Microscopic fluid-filled space between the rounded areas on the end of the axon terminals of one cell and the dendrites or surface of the next cell
• Receptor sites


  Holes in the surface of the dendrites or certain cells of the muscles and glands, which are shaped to fit only certain neurotransmitters
• Excitatory neurotransmitter


  Neurotransmitter that causes the receiving cell to fire
• Inhibitory neurotransmitter


  Neurotransmitter that causes the receiving cell to stop firing
• Central nervous system (CNS)


  Part of the nervous system consisting of the brain and spinal cord

  
• Spinal cord


  A long bundle of neurons that carries messages to and from the body to the brain that is responsible for very fast, lifesaving reflexes
• Three types of neurons

  • Sensory neuron
  • Motor neuron
  • Interneuron
• Sensory neuron


  A neuron that carries information from the senses to the central nervous system, also called an afferent neuron
• Motor neuron


  A neuron that carries messages from the central nervous system to the muscles of the body, also called an efferent neuron
• Interneuron


  A neuron found in the center of the spinal cord that receives information from the sensory neurons and sends commands to the muscles through the motor neurons

  
• Neuroplasticity


  The ability to constantly change both the structure and function of cells in response to experience or trauma
• Peripheral nervous system (PNS)


  All nerves and neurons that are not contained in the brain and spinal cord but that run through the body itself

  
• Divisions of the PNS

  • Somatic nervous system
  • Autonomic nervous system

  
• Somatic nervous system


  Division of the PNS consisting of nerves that carry information from the senses to the CNS and from the CNS to the voluntary muscles of the body

  
• Sensory pathway


  Nerves coming from the sensory organs to the CNS consisting of sensory neurons

  
• Motor pathway


  Nerves coming from the CNS to the voluntary muscles, consisting of motor neurons

  
• Autonomic nervous system (ANS)


  Division of the PNS consisting of nerves that control all of the involuntary muscles, organs, and glands

  
• Sympathetic division


  Part of the ANS that is responsible for reacting to stressful events and bodily arousal
• Parasympathetic division


  Part of the ANS that restores the body to normal functioning after arousal and is responsible for the day-to-day functioning of the organs and glands
• Endocrine glands


  Glands that secrete chemicals called hormones directly into the bloodstream
• Hormones


  Chemicals released into the bloodstream by endocrine glands
• Pituitary gland


  Gland located in the brain that secretes human growth hormone and influences all other hormone-secreting glands (also known as the master gland)

  
• Pineal gland


  Endocrine gland located near the base of the cerebrum that secretes melatonin
• Thyroid gland


  Endocrine gland found in the neck that regulates metabolism