Nervous System

Nervous System

1. Central Nervous System (CNS)

   • Processes and integrates the incoming information of all body parts and coordinates and influences body activities
   • Brain
   • Spinal Cord
   • Stimulus
     • Sensor
       • Sensory Neurons
         • CNS
           • Motor Neurons
             • Effector Cells
               • Reaction
     • Dendrites
       • Cell Body
         • Axon Hillock
           • Axon
             • Insulating Sheath
               • Saltatory Conduction
                 • Conduction of action potentials in an axon with an insulating sheath. Insulating sheath increases the conduction speed of action potentials.
               • Continuous Conduction
                 • Without an insulating sheath. Low conduction speed compared to the saltatory conduction.
               • Synaptic Terminal
                 • Synapse
                   • The transmission of information at synapses
                     • A
                       • An electrical impulse (action potential) reaches the synaptic terminal and causes the synaptic vesicles to fuse with the cell membrane.
                       • B
                         • The synaptic vesicles release neurotransmitter into the synaptic cleft.
                         • C
                           • The neurotransmitter binds to the receptor on the target cell (other neurons).
                           • D
                             • This causes an electrical impulse in the dendrite of the target cell.
                             • E
                               • The neurotransmitter is degraded and recycled in the synaptic terminal.
                     • Neurotoxin
                       • Black widow spider bite
                         • It has an effect on the synaptic cleft Effect on the synapse: permanent signal Effects on organism: permanent excitation -> muscle cramps => death
                       • Botox
                         • It has an effect on the synaptic cleft. Effects on synapse: blocks the release of neurotransmitters Effects on the organism: -widened pupils -disorder of the eye muscle -cramps of the heart and respiration muscles
                       • Nicotine
                         • It has an effect on the receptors but work just like neurotransmitter Effects on the synapse: they can´t recycle and degraded Effects on organism: Increasing blood pressure and pulse
                       • Toxin of the fly agaric and deadly nightshade
                         • It has an effect on the receptors but work just like neurotransmitter Effects on the synapse: they can´t recycle and degraded      ->permanent excitation Effects on the organism: -less swaeting and decreasing heartbeat (deadly nightshade)  -more sweating and increasing heartbeat (fly agaric)

2. Peripheral Nervous System (PNS)

   • Voluntary Nervous System (VNS)
     • Voluntary controls the body
     • Sensory Nerve Cells
     • Motor Nerve Cells
   • Automatic Nervous System (ANS)
     • Is part of the PNS and it unconsciously influences and regulates the internal organs
     • Sympathetic Nervous System
       • Responsible for "fight or run" situations. Therefore the body can react quickly
     • Parasympathetic Nervous System
       • Responsible for "rest and digest" situations. Therefore the body can rest

3. Neurons

   • Cell Body (Soma)
     • Cell Organelles
       • Extensions
         • Axon
           • Axon Hillock
           • Insulating Sheath
             • Synaptic Terminal
               • Synapse
         • Dendrites

Bilder und Dateien der Mindmap

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• Function of Neurotransmitters (Einbetten)