nervous system

• Functions of the Nervous System

  • Sensory input - gathering information
  • Integration - to process and interpret sensory input and decide if action is needed
  • Motor output - A response to integrated stimuli that activates muscles or glands

  
• Central Nervous System (CNS)


  • Brain
  • Spinal cord

  
• Peripheral Nervous System (PNS)


  Nerve outside the brain and spinal cord
• Sensory (afferent) division of PNS


  Nerve fibers that carry information to the central nervous system

  
• Motor (efferent) division of PNS


  Nerve fibers that carry impulses away from the central nervous system
• Neuroglia


  Cells that divide
• Neurons

  Nerve cells specialized to transmit messages, do not divide
• Satellite cells


  Protect neuron cell bodies
• Schwann cells


  Form myelin sheath in the peripheral nervous system

  
• Cell body


  Nucleus and metabolic center of the neuron
• Dendrites


  Conduct impulses toward the cell body
• Axons


  Conduct impulses away from the cell body (only 1 per neuron)
• Sensory (afferent) neurons


  Carry impulses from the sensory receptors

  
• Motor (efferent) neurons


  Carry impulses from the central nervous system

  
• Interneurons (association neurons)


  Found in neural pathways in the central nervous system, connect sensory and motor neurons

  
• Multipolar neurons


  Many extensions from the cell body
• Bipolar neurons


  One axon and one dendrite
• Unipolar neurons


  Have a short single process leaving the cell body
• Irritability


  Ability to respond to stimuli
• Conductivity


  Ability to transmit an impulse

  
• Reflex


  Rapid, predictable, and involuntary responses to stimuli

  
• Reflex arc


  Direct route from a sensory neuron, to an interneuron, to an effector

  
• Types of Reflexes


  • Autonomic reflexes
  • Somatic reflexes
• Central Nervous System (CNS)


  Develops from the embryonic neural tube, becomes the brain and spinal cord

  
• Cerebral hemispheres


  Paired (left and right) superior parts of the brain, include more than half of the brain mass

  
• Gyri


  Ridges on the surface of the cerebral hemispheres

  
• Sulci


  Grooves on the surface of the cerebral hemispheres
• Frontal lobe


  One of the lobes of the cerebrum

  
• Parietal lobe


  One of the lobes of the cerebrum
• Occipital lobe


  One of the lobes of the cerebrum
• Temporal lobe


  One of the lobes of the cerebrum
• Somatic sensory area


  Receives impulses from the body's sensory receptors

  
• Primary motor area

  Sends impulses to skeletal muscles
• Broca's area


  Involved in our ability to speak
• Gustatory area

  Cerebral area involved in taste
• Visual area

  Cerebral area involved in vision
• Auditory area

  Cerebral area involved in hearing
• Olfactory area

  Cerebral area involved in smell
• Speech/language region


  Cerebral interpretation area
• Language comprehension region


  Cerebral interpretation area