Central Nervous System: Brain and Spinal Cord Explained
Parent Guide to How the Brain and Spinal Cord Control Movement, Senses, Memory, and More
What Is the Central Nervous System?
The nervous system has two parts: the central nervous system and the peripheral nervous system. The central nervous system is made up of the brain and spinal cord:
ð§ The Brain
Controls how we think, learn, move, and feel. It's like a central computer that controls all the body's functions.
ðThe Spinal Cord
Carries messages back and forth between the brain and the nerves that run throughout the body.
Protection of the Central Nervous System
Both the brain and the spinal cord are well-protected by multiple layers:
Bone Protection
The brain is protected by the bones of the skull, and the spinal cord by vertebrae (ring-shaped bones of the spine).
Membranes (Meninges)
Layers of protective membranes cushion the brain and spinal cord, providing additional protection.
Cerebrospinal Fluid
Fluid flows through hollow spaces (ventricles) in the brain and around the spine, protecting, nourishing, and removing waste.
What Does the Central Nervous System Do?
The brain is like a central computer that controls all the body's functions. It is in charge of what we think and feel, how we learn and remember, and the way we move and talk. It also controls things we're less aware of â like the beating of our hearts and the digestion of our food. The brain sends messages back and forth with the body through the spinal cord.
Parts of the Brain
ð§ The Cerebrum
The cerebrum is the biggest part of the brain. A large part of the cerebrum is the cerebral cortex (also known as "gray matter"). The cortex has four areas called lobes that work together to create a person's personality and everything they know.
Frontal Lobe
Located behind the forehead. Involved in complex thinking, planning, imagining, making decisions, and reasoning.
Parietal Lobe
Behind the frontal lobe. Processes information about touch, taste, and temperature.
Temporal Lobe
Near the ears. Lets us understand sounds and language, recognize objects and faces, and create memories.
Occipital Lobe
In the rear part of the brain. Processes light and other visual information from the eyes, letting us know what we're seeing.
Two Hemispheres: The cerebrum has two halves (hemispheres) connected by the corpus callosum. The left hemisphere controls the right side of the body, and the right hemisphere controls the left side of the body.
âïļThe Cerebellum
Behind the cerebrum is the cerebellum â also called the "little brain" because it looks like a small version of the cerebrum. The cerebellum is responsible for balance, movement, and coordination. It helps coordinate and fine-tune movement.
ðŋThe Brainstem
The brainstem connects the brain and the spinal cord. It is made up of the pons, the medulla, and the midbrain. These parts work together to control and coordinate the messages going in and out of the brain. The brainstem also controls many body functions that we often don't think about â like breathing, heart rate, blood pressure, swallowing, and digestion.
Pons
Relays messages between cerebrum, cerebellum, and spinal cord
Midbrain
Helps control eye movements and communication
Medulla Oblongata
Regulates vital functions like heartbeat and breathing
Other Important Brain Structures
Thalamus
Receives messages about the senses (vision, hearing, touch) and sends them to the appropriate part of the brain to be interpreted.
Hypothalamus
Controls pulse, thirst, appetite, sleep patterns, and other processes that happen automatically. Regulates hormone release from the pituitary gland.
Pituitary Gland
Makes hormones that control growth, metabolism, water and mineral balance, sexual maturity, and response to stress.
The Spinal Cord
The spinal cord is a long bundle of nerve tissue. In an adult, it's about 18 inches long and 1/2-inch thick. It extends from the lower part of the brainstem down the back.
ðCervical Section
Located in the neck area. Sends nerves to the face and neck.
ðThoracic Section
Located in the chest area. Sends nerves to the arms, chest, and abdomen.
ðLumbar-Sacral Section
Located in the lower back area. Sends nerves to the lower body.
Cauda Equina: At the bottom of the spinal cord is a bunch of nerves that look like a horse's tail (which is what "cauda equina" means in Latin).
âĻAmazing Brain Facts
An adult's brain weighs only about 3 pounds, but it's incredibly complex with many folds and grooves.
The brain contains about 86 billion neurons that communicate through trillions of connections!
Brain signals travel at speeds up to 268 miles per hour!
The brain is about 75% water and uses 20% of the body's total oxygen and energy!
A child's brain grows to about 90% of adult size by age 5!
Your brain never stops working - not even when you sleep! It processes information and forms memories during sleep.
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â ïļMedical Disclaimer
The information provided on this page is for educational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with your child's pediatrician or qualified healthcare provider if you have concerns about your child's health or development. For medical emergencies, call 911 or visit your nearest emergency room immediately. Content compiled from trusted pediatric health references and medically reviewed educational resources.