backboneThe line of back bones that shields the spinal cord. Each of its bones is a vertebra. Another name for it is the spine.
brainThe body's control center, housed inside the head. An adult human brain weighs about three pounds.
central nervous systemThe brain plus the spinal cord, both cased in bone. The skull guards one and the backbone guards the other.
nerveA cable of fibers along which messages travel. Nerves link the brain and spinal cord to the muscles, the skin and the organs.
nervous systemThe body's network of brain, spinal cord and nerves. It gathers information, decides what it means and sends orders to the muscles.
neuronA single nerve cell; the nervous system is built of them. A neuron has a cell body, dendrites and an axon.
peripheral nervous systemThe nerves that reach out beyond the spinal cord and brain. It connects the central nervous system to the rest of the body.
reflexA quick action the body takes without thinking. A reflex pulls a hand back from something painful before the pain is felt.
sense organA body part, like the eye or ear, that gathers information. The nose, the tongue and the skin are sense organs too.
skullThe head bones, joined into a shell round the brain. The part around the brain is called the cranium.
spinal cordThe cord of nerve tissue from the brain down the back. It carries messages up to the brain and back down to the body.
stimulusA change, like a noise, that sets off a reaction. Light, sound and heat are stimuli; stimuli is the plural.
Show all 36 terms (24 more)
Parts of the brain 12
brainstemThe stem under the brain that leads to the spinal cord. Its three parts are the midbrain, the medulla oblongata and the pons between them.
cerebellumThe part beneath the cerebrum that guides skilled movement. It is the second largest part of the brain.
cerebral cortexThe gray sheet of tissue that coats the cerebrum. The word cortex is Latin for bark.
cerebral hemisphereOne of the two big sides that make up the cerebrum. The right hemisphere mostly runs the body's left side.
cerebrumThe biggest region of the brain, used for thinking. Memories are kept in the cerebrum.
corpus callosumThe bridge of nerve fibers between the two hemispheres. The two hemispheres send messages to each other through it.
frontal lobeThe front lobe of the cerebrum, where plans are made. It lies just behind the forehead and is the largest lobe of the brain.
medulla oblongataThe brainstem's lowest part; it keeps you breathing. It also helps control the heart rate.
motor cortexThe strip of cortex that directs chosen movement. It lies at the back of the frontal lobe. Kicking a ball is a movement it helps to plan.
occipital lobeThe rearmost lobe, which handles seeing. It works on the pictures that come in from the eyes.
parietal lobeThe upper lobe of the cerebrum, which takes in touch. It also takes in information about temperature and taste.
temporal lobeThe side lobe, near the ear, that handles hearing. It also helps to form memories and bring them back.
Neurons and signals 12
axonThe long thread that sends a neuron's messages on. An axon may be very short or may run the length of the spinal cord.
cell bodyThe rounded center of a neuron, home of its nucleus. Another name for the cell body is the soma.
dendriteA branching arm of a neuron that takes in messages. The word comes from the Greek for tree.
glial cellA cell that supports and protects nerve cells. Glial cells carry no nerve impulses of their own.
motor neuronA neuron that tells a muscle or a gland what to do. It carries its signal outward from the brain or the spinal cord.
myelin sheathThe insulating coat of fat around a nerve fiber. Signals travel faster along a fiber that has a myelin sheath.
nerve impulseA pulse of electricity moving along a neuron. Another name for a nerve impulse is an action potential.
neurotransmitterA chemical that carries a signal between cells. Dopamine and serotonin are neurotransmitters.
optic nerveThe nerve that carries what the eye sees to the brain. It is one of the twelve pairs of cranial nerves, which leave the brain itself.
sensory neuronA neuron that brings signals in from a sense organ. It takes signals toward the brain and the spinal cord.
sensory receptorA cell or nerve ending that detects light, heat or touch. Receptors in the skin detect touch; receptors in the eye detect light.
synapseThe spot where a neuron passes its message to a neighbor. The next cell may be another neuron, a muscle cell or a gland cell.
How this list was compiled: Term list chosen for this site on 2026-10-11. Each meaning is written in our own words and was checked that day against the English Wikipedia article on the term (https://en.wikipedia.org/), whose text is under the Creative Commons Attribution-ShareAlike license: Nervous system, Brain, Human brain, Spinal cord, Nerve, Neuron, Reflex, Reflex arc, Stimulus (physiology), Sense, Central nervous system, Peripheral nervous system, Skull, Vertebral column, Cerebrum, Cerebellum, Brainstem, Medulla oblongata, Cerebral cortex, Cerebral hemisphere, Corpus callosum, Lobes of the brain, Frontal lobe, Parietal lobe, Temporal lobe, Occipital lobe, Motor cortex, Dendrite, Axon, Synapse, Soma (biology), Myelin, Neurotransmitter, Action potential, Glia, Sensory neuron, Motor neuron, Optic nerve and Cranial nerves. Each was checked a second time against pages of the U.S. National Institutes of Health: Brain Basics: Know Your Brain, of the National Institute of Neurological Disorders and Stroke (https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-know-your-brain), for the parts of the brain, the lobes, the neuron and the synapse; and the Nervous System pages of the SEER Training Modules of the National Cancer Institute (https://training.seer.cancer.gov/anatomy/nervous/) for the divisions of the system, nerve tissue, the spinal cord, reflexes, receptors and the cranial nerves. Backbone and sense organ were also checked in Wiktionary, the free dictionary (https://en.wiktionary.org/). The fact after each meaning is from the same pages. Licence: own work
How it works
These nervous system worksheets for 4th grade print twelve terms, from brain and spinal cord to neuron and reflex, to match to their meanings, with an answer key. It is a nervous system vocabulary worksheet with no diagram to label.
Read the full guide
A brain vocabulary worksheet
Set opens on The nervous system. Parts of the brain prints cerebrum, cerebellum, brainstem, medulla oblongata, cerebral cortex, cerebral hemisphere, corpus callosum, motor cortex and the frontal, parietal, temporal and occipital lobes.
Neurons and signals
The third set has the parts of a nerve cell and the words for its signals: dendrite, axon, synapse, cell body, myelin sheath, neurotransmitter, nerve impulse, glial cell, sensory neuron, motor neuron, sensory receptor and optic nerve.
Thalamus, hypothalamus and hippocampus are not in these sets.
Questions and answers
What are the main parts of the nervous system?
The brain, the spinal cord and the nerves. The brain and spinal cord form the central nervous system. The nerves that reach from them to the rest of the body form the peripheral nervous system.
What is the difference between a neuron and a nerve?
A neuron is a single nerve cell. A nerve is a bundle of the long fibers of many neurons, wrapped together like a cable.
What is a reflex?
A reflex is a response to a stimulus that takes no conscious thought, which makes it quicker than an action you plan. Many reflexes are handled in the spinal cord and do not go up to the brain first.
Is there a nervous system worksheet for 3rd grade or 5th grade?
The same page serves them: no grade is printed on the sheet. The first set has brain, nerve, spinal cord and reflex. The other two sets go further, to the lobes of the brain and to axons and synapses.