[1] The reflex rapidly coordinates the contractions of all the flexor muscles and the relaxations of the extensors in that limb causing sudden withdrawal from the potentially damaging stimulus.
[3] When a person touches a hot object and withdraws their hand from it without actively thinking about it, the heat stimulates temperature and pain receptors in the skin, triggering a sensory impulse that travels to the central nervous system.
[6] Once a danger receptor (called "nociceptor") has been stimulated, the signal travels via the sensory nerve to the dorsal (posterior) horn of the spinal cord.
The nerve synapses with ipsilateral motor neurons that exit the ventral (anterior) horn of the spinal cord and work to pull the soon-to-be injured body part away from danger within 0.5 seconds.
At the same time as these two synapses, the sensory neuron also sends signals along the spinal cord to get motor neurons to contract muscles that shift the center of gravity of the body to maintain balance.