The Nervous System
In order to understand why we feel pain, it's important to know a little about the body's nervous system, an elaborate network of nerves whose control center is the all-important brain. The nervous system is the body's most complex system and regulates hundreds of activities — all at the same time.
At the center of the nervous system is the brain, which is the root of your consciousness, the center of your intellect, and the basis of your creativity. The brain also regulates your autonomic processes, all those things your body does that don't require a moment of conscious thought, such as breathing, blinking, and heart rate.
The nervous system is made up of several distinct parts, each with several unique roles. Think of it as a collection of electrical wires and impulses, all activated and regulated by the brain.
The Central Nervous System (CNS)
The central nervous system (CNS) is made up of the brain and the spinal cord. The brain is the hub of all information processing and bodily functions, while the spinal cord links the peripheral nervous system to the brain. The brain controls reflexes and is the initial pain processing center.
The brain, which weighs all of about three pounds, is nestled securely in your skull, where it houses about 100 billion neurons, or nerve cells, that are constantly transmitting information among cells. It is the place where all impulses originate and where all impulses travel. Absolutely everything we do, from casting a nasty glance or laughing at a joke to reading a book or learning a musical instrument, requires our brain.
Over time, many luminaries have sounded off on pain. Leonardo da Vinci and his contemporaries came up with the idea that the brain was the main organ responsible for sensation and that the spinal cord was the part that transmitted pain. The poet Emily Dickinson said pain had “no future but itself.” The twentieth-century French missionary Albert Schweitzer described pain as a “more terrible lord of mankind than even death itself.”
The Peripheral Nervous System (PNS)
The peripheral nervous system (PNS) is an elaborate network of nerve fibers that branch out from the brain and spinal cord to the far reaches of your body, such as your fingertips. This network has the vital task of constantly receiving information from inside and outside the body, then relaying that information to the brain to find out what to do. The PNS is made up of two parts.
The Sensory Somatic Nervous System
Swallowing, chewing, a wiggle of your toes. All these tasks are performed by the sensory somatic nervous system. This system kicks into gear, either voluntarily or involuntarily, when your senses are stimulated by external stimuli such as food, texture, and sound, or by conscious desires, such as when you want to move.
The Autonomic Nervous System
Anything involuntary that we do is regulated by the autonomic nervous system. Blinking, breathing, and digestion are all processes regulated by this system. It also alerts us to danger, tells our intestines to digest our food, and responds to our emotions.