Describe how the structures involved in a reflex action help co-ordinate a reflex: (image with receptor, effector, spinal cord, synapse and neurones)

A receptor detects a stimulus e.g. pressure. The receptor generates electrical signals. Neurones conduct impulses, a sensory neurone conducts to the spinal cord. There is a synapse between the neurones and the chemical neurotransmitter crosses the synapse. The neurotransmitter stimulates an impulse in the relay neurone. The relay neurone carries the impulse to the motor neurone which acts on the effector. The effector then carries out a response e.g. a muscle would contract/ a gland would release it’s hormone.