Your nervous system is what co-ordinates the activity of all your muscles, monitors how your organs are functioning, collects data from all five senses, and initiates movement. The nervous system is made up of ‘nervous tissue’, and includes neurons and nerves. The brain and spinal chord together form the main hub, known as the central nervous system. The nerves all over your body that carry impulses to and from the brain and spine are known as the peripheral nervous system.
The network of peripheral nerves in your body consists of 12 pairs of cranial nerves, attached to your brain and serving your head and neck, and 31 pairs of spinal nerves, attached to your spinal cord and serving the rest of your body. Your peripheral nerves enable you to carry out both voluntary and involuntary actions. When you decide to kick a football, run for a bus or click your fingers, these are all voluntary actions. Your brain has received and processed information about the situation, for example, how far the football is from your foot, or how far the bus is from the stop, and decided what to do next. But your heart keeps on beating and your intestines digest the food you’ve eaten without you consciously deciding to do it. These are involuntary actions, controlled by your ‘autonomic’ nerves, which keep your internal organs and glands functioning smoothly.
Your nerves also control your ‘fight-or-flight’ mechanism, which prepares your body for emergencies, by providing extra blood to your muscles, increasing your blood pressure, and speeding up your breathing and your heart pumping. This is your body’s automatic physical response to stress.