1. Reflex arc starter 1 © www.teachitscience.co.uk 201320143

2. Name the parts of the reflex arc Transverse section through spinal cord Sensory neurone receptor 1 2 relay neuron 3 grey matter white matter 4 5 motor neurone 6 effector (muscle) 7 2 © www.teachitscience.co.uk 201320143

3. sensory neurone stimuli contracts spinal central relay impulses effector receptor spinal cord nervous response grey matter system synapse chemical When there is a stimulus the __________ in the skin is stimulated. Electrical __________ pass along the __________ neurone to the CNS (_________ _________ _________). At a __________ a __________message is released. This crosses the synapse and starts an electrical impulse in the __________ neurone. When another synapse is reached another chemical message crosses it and a new impulse is started down the _______ neurone. When this reaches an __________ (e.g. a muscle) it causes a _________ (e.g. the muscle __________). receptor impulses sensory centralnervous system synapse chemical relay motor effector responsecontracts Complete these sentences 3 © www.teachitscience.co.uk 201320143