Bio 216: Nervous System, Neuron, Sensory Systems

Bio 216: Nervous System, Neuron, Sensory Systems

1. Nervous System

   • CNS
     • composed of
       • brain
         • development
           • at 4 weeks
             • forebrain
               • at 5 weeks
                 • telencephalon
                   • adult
                     • cerebrum
                 • diencephalon
                   • adult
                     • thalamus
                     • hypothalamus
             • midbrain
               • 5 weeks
                 • mesencephalon
                   • adult
                     • midbrain
             • hindbrain
               • at 5 weeks
                 • metencephalon
                   • adult
                     • cerebellum
                     • pons
                 • myelancephalon
                   • adult
                     • medulla oblongata
         • lobes
           • frontal
             • functions
               • thinking
               • organizing
               • planning
               • problem solving
               • memory
               • attention
               • movement
           • parietal
             • function
               • perception
               • integration of senses
           • occipital
             • vision
           • temporal
             • function
               • smell
               • taste
               • sound
               • formation and storage of memories
       • spinal cord
   • PNS
     • divided into
       • afferent system
         • receptors to CNS
       • efferent system
         • CNS to effectors
         • divided into
           • somatic
             • mostly voluntary
           • autonomic
             • involuntary
             • divided into
               • sympathetic
                 • involves
                   • fight or flight
               • parasympathetic
                 • involves
                   • "rest or digest"

2. Neuron

   • structure
     • in order of signal propogation
       • dendrites
         • cell body
           • nucleus
             • axon hillock
               • axon
                 • signal velocity increased by
                   • myelin sheath
                   • saltatory conduction
                     • along
                       • nodes of Ranvier
                 • axon terminal
   • signal conduction
     • resting potential
       • -70mV
       • established by
         • sodium
         • potassium
     • acetycholine
       • stimulates
         • opening of Na+ voltage-gated channels
           • causing
             • membrane potential to depolarize
               • threshold reached
                 • rapid influx of + charges
                   • after peak of AP
                     • repolarization
                       • hyperpolarization
                         • refractory period
                         • return to
                           • resting potential
                       • both
                 • -50mV
   • membrane potential established by
     • difference in electrical charge on 2 sides of the membrane