The body's wiring in one page: the central nervous system (brain and spinal cord), the peripheral nervous system, and its somatic and autonomic divisions.
Neuroscience Foundations
Beginner
The Nervous System at a Glance
The Editors
May 22, 2026
2 min read
In plain English
Your nervous system has a headquarters — the brain and spinal cord — and a huge network of cables, the nerves, that carry messages to and from every part of the body. Some of those messages you control, like moving a finger; many you don't, like your heartbeat.
Beginner level: No background needed. Everyday language, everyday examples — the place to start.
Concepts to know first
The nervous system is usually divided into two main parts. The central nervous system (CNS) is the brain and the spinal cord, protected inside the skull and the spine. The peripheral nervous system (PNS) is everything else: the nerves that branch out from the brain and spinal cord to the skin, muscles, glands and organs.
The peripheral nervous system
The PNS is split by job. The somatic nervous system handles things you can sense and control: it carries touch, temperature and pain from the skin and joints, and sends commands to the skeletal muscles that move your body.
The autonomic nervous system runs the body's automatic housekeeping: heart rate, breathing rhythm, digestion, pupil size, sweating and more. It has two opposing branches — the sympathetic ("fight or flight") and the parasympathetic ("rest and digest") — plus the enteric nervous system, a mesh of hundreds of millions of neurons in the gut wall.
Afferent and efferent
Two words help: afferent nerves carry signals toward the CNS (sensation), and efferent nerves carry signals away from it (commands to muscles and glands). Most nerves contain both kinds of fibre, bundled together like a cable with many separate wires.
Not just the brain
The spinal cord does real processing of its own: simple reflexes, like pulling your hand from a hot stove, are organised there before the brain even knows what happened. And the brain is in constant two-way conversation with the body, through nerves, hormones and the immune system.
Everyday examples & things to try
Analogy
Headquarters and field offices
The brain is company headquarters, the spinal cord is the main trunk line out of the building, and the peripheral nerves are the cables running to every branch office. The autonomic system is the building's automatic heating, lighting and plumbing — it runs whether or not anyone at headquarters is paying attention.
Key takeaways
- Central nervous system = brain + spinal cord; peripheral = all other nerves.
- The somatic system handles voluntary movement and body sensation.
- The autonomic system runs automatic functions through sympathetic, parasympathetic and enteric branches.
Explore further
Search YouTube for…
Tap a phrase to copy it, then paste it into YouTube's search box. This site doesn't link to other websites — pick channels from universities, hospitals and established science educators.
Tagsbasicsanatomyoverview
Keep reading
Neuroscience Foundations
Beginner
What Is Neuroscience?
Neuroscience is the scientific study of the nervous system — the brain, spinal cord and nerves — and of how its cells and circuits produce everything from a heartbeat to a memory.
October 10, 2026 · 3 min read
Neuroscience Foundations
Beginner
The Branches of Neuroscience
From molecules to minds: a map of the sub-fields of neuroscience — molecular, cellular, systems, cognitive, computational, clinical and more — and what each one actually studies.
July 16, 2026 · 2 min read
Neuroscience Foundations
Beginner
Brain Myths, Debunked
No, you don't use only 10% of your brain — and you aren't 'left-brained' or 'right-brained' either. A tour of the most popular brain myths and what the science actually says.
December 14, 2025 · 3 min read