The nervous system produces a coordinated response because it reaches all parts of the body. Nerves branch from the spinal cord to the skin, muscles and organs, so receptors anywhere can send information in and effectors anywhere can be told what to do.
It also has many links. Neurones connect to many other neurones in the CNS, so one stimulus can lead to several responses at once. The CNS can also bring together information from different sensory receptors, such as the eyes, ears and skin, and use all of it to decide on the best response. This is why you can see a ball coming, judge how fast it moves and catch it.
Nerve impulses are very fast, so the response happens quickly. The time between a stimulus and the response is the reaction time. A common practical is to drop a ruler and have a person catch it. The shorter the distance the ruler falls before it is caught, the shorter the reaction time. The test should be repeated several times and a mean calculated, which makes the result more reliable. Reaction time can change, for example with tiredness or after caffeine, so the other variables must be controlled.