the nervous system

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    Created by
    krisha

    Cards (20)

    • what is the nervous system (NS)
      specialised network of cells in the human body and is our primary internal communication system
    • two main functions of NS
      1)to collect, process, & respond to information in the environment
      2)to co-ordinate the working of different organs and cells in the body
    • what is the NS subdivided into?
      1)central nervous system (CNS)
      2)peripheral nervous system (PNS)
    • what is the CNS made up of?
      brain, spinal cord
    • define the brain
      -centre of all conscious awareness
      -the brains outerlayer: the cerebral cortex ->more developed in humans than in all other animals
      -divided into two hemispheres
    • define the spinal cord
      -extension of the brain
      -transports messages from the brain to the PNS
      -responsible for reflexes
    • role of the peripheral nervous system?
      transmit messages, via millions of neurons, to & from the CNS
    • what is the PNS subdivided into?
      autonomic nervous system (ANS) , somatic nervous system (SNS)
    • what is the autonomic nervous system responsible for ?(ANS)
      responsible for vital functions such as breathing, heart rate, digestion, sexual arousal & stress responses
    • what is the somatic nervous system responsible for?
      controlling muscle movement & receiving information from sensory receptors
    • what is the ANS further subdivided into?
      -sympathetic nervous system (SPNS)
      -parasympathetic nervous system (PSNS)
    • what response is the SPNS associated with?
      The SPNS is associated with the 'fight or flight' response in tandem with the endocrine system
    • what does the SPNS prepare the body for and when?
      The SPNS prepares the body for physical activity when the hypothalamus detects a stimulus which requires attention/action, e.g.
      -running away from a threat
      -standing and facing the threat
      -preparing to fight the threat
    • when is the SPNS triggered?
      The SPNS is triggered when the body is in an 'alert' state, e.g.
      -when crossing the road
      -when a noise is heard late at night
    • what happens when the SPNS is triggered?
      Adrenaline is released from the adrenal glands to fuel any physical activity required of the body along with other physiological changes
    • list some physiological changes when SPNS is triggered
      -increased heart rate, breathing rate
      -dilates pupils
      -inhibits digestion, saliva production
      -contracts rectum
    • what does the SPNS allow for as a result?
      The SPNS thus enables a fast, automatic response to a possible threat or dangerous situation (but it can also occur when someone is highly elated or excited)
    • what is the PSNS known as?
      -known as the 'rest and digest' system
      -PSNS is the body at rest -usual state which preserves energy
    • what does the PSNS help the body to do? how?
      helps to conserve the body's activity levels and energy by decreasing activity which may be needed later
    • list the physiological actions the PSNS controls
      -decreases heart rate, breathing rate
      -constricts pupils
      -stimulates digestion, saliva production
      -relaxes rectum
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