3.1

• CNS

  consists of the brain and spinal cord
• PNS


  Consists of the somatic nervous system and autonomic nervous system
• Somatic nervous system


  contains sensory and motor neurons
• Sensory neurons

  take impulses from sense organs to the CNS
• Motor neurons

  take impulses from the CNS to muscles and glands
• Autonomic nervous system

  consists of the sympathetic and parasympathetic systems
• Sympathetic system

  speeds up heart rate and breathing rate, slows down peristalsis and production of intestinal secretions.
• Parasympathetic systems

  slows down heart rate and breathing rate, speeds up peristalsis and production of intestinal secretions.
• Converging neural pathway

  Impulses from several neurons travel to one neuron. This increases the sensitivity to excitatory or inhibitory signals.
• Diverging neural pathway

  impulses from one neuron travel to several neurons so affecting more than one destination at the same time.
• Reverberating neural pathway

  neurons later in the pathway link with earlier neurons, sending the impulse back through the pathway.