Describe the events involved all the way to the brain when a person accidentally steps on a nail.

Answer and Explanation:

Pain receptors are stimulated in the skin generating an impulse. The impulse is conducted by the sensory neuron to the spinal cord. The neuron conveys the impulse to the CNS where it makes synaptic neuron connect with the motor neuron. The motor neuron conveys the impulse to the muscles of the leg. Contraction of the muscle results in withdrawal of the leg from the nail.