nervous system

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Created by
anya

Cards (14)

  • What is the nervous system?
    -Primary communication system in the body
    -Over 100 billion neurons in brain & body
    -Electric & chemical signals
    -Responds to what is going on both externally & internally
  • The nervous system (CNS)
    NERVOUS SYSTEM --> Central nervous system --> Spinal cord & brain
  • The nervous system (PNS --> somatic nervous system)

    NERVOUS SYSTEM --> Peripheral nervous system --> Somatic nervous system
  • The nervous system (PNS --> autonomic nervous system)

    NERVOUS SYSTEM --> Peripheral nervous system --> Autonomic nervous system --> Parasympathetic nervous system & Sympathetic nervous system
  • Spinal cord

    -An extension of the brain
    -Passes messages from to & from the brain & connects nerves to the peripheral nervous system
    -Responsible for reflex actions
  • Brain

    -Centre of consciousness
    -Brain's outer layer is the cerebral cortex which is highly developed in humans
    -Divided into 2 hemispheres & 4 key lobes
  • Main role of peripheral nervous system

    Relays information to & from the central nervous system
  • 2 main parts of the peripheral nervous system
    Somatic & Autonomic
  • Somatic nervous system

    -Has sensory & motor pathways
    -The motor cortex controls voluntary muscles
    -The brain stem/spinal cord for reflex arc
    -Takes in information from the external environment via sensory receptor cells which then pass the information via sensory neurons to the central nervous system
    -Controls voluntary skeletal muscles movement via motor neurons
  • Autonomic nervous system

    -Has motor neuron pathways
    -Come from brain stem
    -Controls internal organs & glands which govern vital functions in the body such as breathing, heart rate, digestion, sexual arousal & stress response
    -Involuntary movement
  • Sympathetic nervous system

    -Triggers fight/flight as apart of the stress response
    -Helps respond to danger: survival
    -Needs to move fast: so breath faster & heart beats faster, get more O2 in muscles
  • Parasympathetic nervous system
    -When stress is over, it returns the body back to resting state
    -Slows heartrate, stimulates digestion
  • Fight/flight response

    -Sympathetic nervous system
    -Adrenalin is released by the Adrenal gland
    -Heart rate & breathing speeds up so oxygen can get to the muscles for quick reactions
    -Pupils dilate to take in more light so you can see better in the dark
    -Digestion stops so energy is focused on stress rather digestion
  • Overuse of fight/flight system
    In our evolutionary past fight/flight made sense for survival but in modern times the brain is bombarded with information coming in
    This leads to some developing a hyper-sensitive stress response so they go into fight/flight over things which don't threaten their survival
    Being biologically stuck in survival mode can led to health issues
    To control it, they need to try & get their parasympathetic system to kick back in relax again