AO1 Nervous System

• What is the nervous system?

  A specialised network of cells in the human body. It is our primary internal communication system
• The two main functions of the nervous system are:

  • To collect, process and respond to information in the environment
  • To coordinate the workings of different organs and cells in the body
• What are the two sub systems the nervous system can be divided into?

  Central nervous system (CNS) and the Peripheral nervous system (PNS)
• What is the CNS made up of?

  The brain and the spinal cord
• The brain is the centre of all conscious awareness
• What is the outer layer of the brain called?

  Cerebral cortex
• The cerebral cortex is highly developed in humans and is what distinguishes our higher mental functions from those of animals
• How thick is the cerebral cortex?

  3 mm
• There are 2 hemispheres in the brain. The left hemisphere and the right hemisphere
• What is the spinal cord?


  An extension of the brain
• What does the spinal cord do?


  Responsible for reflex actions and passing messages to and from the brain. It also connects nerves to the Peripheral nervous system
• What does the peripheral nervous system do?

  Relays messages from the environment to the CNS, via sensory neurones, and from the CNS to effectors, via motor neurones.
• What are the two strands of peripheral nervous system?

  Somatic and Autonomic
• What does the somatic nervous system do?

  Receives information from sensory receptors belonging to each of the senses and results in effectors being stimulated by the Central nervous system via motor neurones
• What does the autonomic nervous system do?

  Controls involuntary, vital functions of the body, such as maintains heart rates and breathing rates
• Which of the PNS sub-systems can be further divided?

  Autonomic
• What can the autonomic nervous system be subdivided into?

  Sympathetic and parasympathetic nervous system
• What does the sympathetic nervous system do?

  Activates the "fight or flight" response in the body.
• What could the sympathetic nervous system do?

  Increase heart rates, breathing rate and pupil dilation
• What does the parasympathetic nervous system do?

  Relax the body and return us to ‘normal’ resting state
• What does the sympathetic nervous system suppress?

  Less important functions like digestion, salivation and desire to urinate
• What is the peripheral nervous system ?

  Nerves outside the brain and spinal cord.
• What does the peripheral nervous system do?

  Relay messages (nerve impulses) from the CNS to the rest of the body.
• What is the peripheral nervous system made up of?


  Nerves outside the CNS
• What does the peripheral nervous system do?


  Connects the CNS to the rest of the body, transmitting sensory information to the CNA and carrying out motor commands form the CNS to muscles and organs