The nervous system

• Biopsychologists assume that behaviour and experiences are caused by activity in the nervous system.
• The nervous system transmits signals for communication via the 100 billion nerve cells it houses.
• These cells communicate with eachother through electrical and chemical messengers.
• • Short dendrites
  • Long axons
  • Carries messages from the CNS to effectors.

  Motor neuron
• • Short dendrites
  • Short axons
  • Transfers messages from sensory neuron to other neurons.

  Relay neuron
• • Carries messages from the PNS to the brain/spinal cord.


  Sensory neuron
• The PNS transmits messages via millions of neurons to and from the CNS system. Subdivided into:

  • Autonomic NS (ANS) - governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses.
  • Somatic NS (SNS) - governs muscle movement and receives information from sensory receptors.


  Peripheral Nervous System
• ANS subdivided into:

  • Sympathetic nervous system
  • Parasympathetic nervous system
• Made up of the brain and spinal cord.

  • Brain is the centre of all conscious awareness.
  • Spinal cord is an extension ofthe brain - it passes messages to and from the brain and connects to the PNS.


  Central Nervous System
• The brain’s outer layer, the cerebral cortex, is highly developed in humans and is what distinguishes our higher mental functions from those of animals.
• • An extension of the brain.
  • Responsible for relaying information between the brain and the rest of the body.
  • Also contains circuits of nerve cells that enables us to perform reflex actions e.g. pulling your hand away from a hot plate.


  The Spinal Cord