Nervous system

• Central Nervous System (CNS)


  - consists of the brain and spinal cord

  - responsible for reflex actions
• Peripheral Nervous System (PNS)


  - comprises the somatic and automatic nervous systems

  (SNS + ANS)

  - transmits messages from the environment to the CNS, via sensory neurons, and from the CNS to effectors, via motor neurons.
• Automatic Nervous System (ANS)


  - the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart)

  - The ANS responsible for involuntary movement to achieve physiological functions like breathing, pumping blood around the body, and digestion.

  - governs vital functions like breathing and heart rate

  - its sympathetic division arouses; its parasympathetic division calms.
• Somatic Nervous System (SNS)


  - the part of the peripheral nervous system that controls voluntary muscle movement: such as coordinating arms to catch a ball.

  - transmits sensory information from sensory receptors to CNS.

  - transmits information from brain (via spinal cord) to muscles to produce voluntary movements

  - SNS integrates the brain with the outside world
• The Nervous System


  - carries information from one part of the body to another using individual nerve cells (neurons)

  - neurons transmit nerve impulses in the form of electrical signals

  - many aspects of behaviour are under neural control, like breathing, eating and sexual behaviour.

  - works in collaboration with the endocrine system to enable physiological and behavioural changes to occur (eg: fight/flight response)
• Why is the CNS reliant on the PNS?

  The CNS is protected by layers of tissue and bone so is reliant on the PNS to provide sensory information from the environment.
• How does the brain produce a motor response?


  The brain acts upon sensory information to produce motor responses via the spinal cord and peripheral nerves.
• What does the sympathetic division of the ANS do?


  creates arousal in the fight or flight response
• What does the parasympathetic division of the ANS do?


  returns the body to a state of calm once the threat has passed.