Reflexes

• Reflex action sequence

  1. Receptors detect impulse
  2. Electrical impulse travels along sensory neurone
  3. Synapse between sensory neurons and relay neurone
  4. At the synapse NTM move across gap
  5. New impulse moves through motor to muscle.
  6. Muscle contracts
• Reflex action is

  Automatic

  Rapid

  Without thought
• Reflex neurones - specially adapted cells that transmit electrical impues
• Sensory neurones and motor neurones- long
• The reflex arc has three types of neurones, sensory, relay and motor.
• Relay neurones are short
• Relay neurones are found in the spinal cord or brain stem
• Motor neurones carry information from the CNS to effectors (muscles)
• Sensory neurones carry information from receptor organs to the CNS
• Receptor cells are specialised nerve endings which respond to stimuli from outside or inside the body
• Stimulus = something that causes a response
• Receptor cells in the sense organ(skin in this instance) is stimulated. electrical impulse sent along sensory neurone then to spinal cord
• Impulse from sensory neurone- brain process- becomes aware