the nervous system

• The Nervous System

  Detects and Reacts to Stimuli
• The Nervous System

  • Made up of Different Parts
  • Central Nervous System (CNS)
  • Peripheral Nervous System (PNS)
• Sensory Neurones


  Carry information as electrical impulses from the receptors to the CNS
• Motor Neurones


  Carry electrical impulses from the CNS to effectors
• Effectors

  All your muscles and glands, which respond to nervous impulses
• Receptors and Effectors

  1. Can form part of Complex Organs

  2. Receptors detect stimuli

  3. Effectors respond to impulses and bring about change

  4. Muscles contract

  5. Glands secrete hormones
• Receptors can be found in large numbers, up to 50 per square millimetre of skin
• The Central Nervous System (CNS) coordinates the response to stimuli
• Response to a stimulus

  1. Receptors detect stimulus

  2. Sensory neurones carry information to CNS

  3. CNS decides what to do

  4. Motor neurones carry information to effectors

  5. Effectors respond
• Simple animals like jellyfish don't have complex nervous systems, everything they do is a reflex response