What Is the Nervous System? Brain, Spinal Cord, and Nerves
Learn what the nervous system is, what structures it includes, how it controls body functions, thought, and senses, and the key terms used to describe the brain, spinal cord, nerves, and signaling.
Nervous System: Brain, Spinal Cord, Nerves, and Key Terms
The nervous system is the body’s command center. It is made up of the brain, spinal cord, and nerves, all of which work together to control body functions, thought, movement, and the senses. This system sends electrical signals throughout the body so it can detect information, process it, and respond appropriately.
The nervous system is divided into two main parts: the central nervous system and the peripheral nervous system. Together, these structures help the body respond to internal and external changes and maintain overall balance.
What Does the Nervous System Do?
The nervous system performs several important functions that are necessary for daily life and overall health.
Sensing and Responding
The nervous system detects stimuli such as heat, sound, touch, and pain. It then helps the body react, such as pulling a hand away from a hot surface.
Coordination
The nervous system controls voluntary movements such as walking and talking. It also regulates involuntary functions such as breathing, heart rate, and digestion.
Higher Functions
The brain manages thinking, memory, learning, emotions, and decision-making.
Main Parts of the Nervous System
The nervous system includes several key structures.
Brain
The brain is the control center of the body. It processes information, directs actions, and supports memory, learning, emotions, and the senses.
Spinal Cord
The spinal cord is a long bundle of nerve tissue that connects the brain to the rest of the body. It carries messages between the brain and peripheral nerves.
Nerves
Nerves are bundles of fibers that carry signals throughout the body. They send sensory information to the brain and spinal cord and carry instructions back to muscles and organs.
Divisions of the Nervous System
The nervous system is organized into two major divisions.
Central Nervous System (CNS)
The central nervous system includes the:
- Brain
- Spinal cord
This division processes information and helps control the body’s responses.
Peripheral Nervous System (PNS)
The peripheral nervous system includes the:
- Cranial nerves
- Spinal nerves
- Nerves that extend throughout the body
This division carries messages between the central nervous system and the rest of the body.
How the Nervous System Works
The nervous system works by receiving information, processing it, and creating a response.
Input
Sensory nerves detect changes such as heat, pain, pressure, light, or sound.
Processing
Signals travel to the spinal cord and brain, where the information is interpreted.
Output
The brain and spinal cord send signals back through nerves to muscles or organs so the body can respond.
How the Nervous System Works: Touching a Hot Surface
A simple example can help explain how the nervous system works.
- Input: Sensory nerves detect heat and pain
- Processing: Signals travel to the spinal cord and brain
- Output: The brain sends signals to the muscles to pull the hand away while also recognizing the pain
Important Nervous System Terms
Understanding these key terms can make the nervous system easier to study.
- Brain: The organ that controls thought, memory, emotions, movement, and the senses
- Spinal cord: The structure that carries messages between the brain and the body
- Nerve: A bundle of fibers that carries electrical signals
- Neuron: A nerve cell that sends and receives information
- Stimulus: A change inside or outside the body that triggers a response
- Reflex: A fast, automatic response to a stimulus
Common Prefixes and Suffixes
Medical terminology related to the nervous system often includes specific prefixes and suffixes.
Prefixes
- Neuro-: Relating to nerves or the nervous system
- Encephalo-: Relating to the brain
- Myelo-: Relating to the spinal cord or bone marrow
- Cerebro-: Relating to the brain
Suffixes
- -itis: Inflammation
- -pathy: Disease or disorder
- -logy: Study of
- -oma: Tumor
Managing Nervous System Health
There are several ways to support nervous system health.
Calming the Nervous System
Deep breathing, gentle movement, good sleep, mindfulness, and time in nature can help regulate the nervous system.
Signs of Possible Problems
Symptoms such as headaches, tingling, weakness, memory loss, or learning difficulties can be signs that the nervous system is not working as expected.
Why the Nervous System Matters
The nervous system is essential because it helps the body sense the world, process information, and respond in coordinated ways. It supports movement, thought, memory, emotions, and automatic body functions that are necessary for life.
A clear understanding of the nervous system helps explain how the body communicates internally and how it reacts to everyday experiences.