This article covers the medical terminology of the nervous system. The nervous system is a very complex system that is vital to the functioning of the human body.
The nervous system is comprised of the central nervous system (CNS) and peripheral nervous system (PNS). There are 31 pairs of spinal nerves and 12 pairs of cranial nerves.
This article will contain a list of word roots, and a few additional suffixes and prefixes related to the nervous system. There are terms related to nervous system specialties and the definitions.
There is also a list of nervous system structures and procedures. Finally, there is a list of some diseases and conditions related to the nervous system.
If you need a background on how medical terms are formed, read the article on Medical Terminology Basics.
Also, the article 11 Rules for Changing Singular Terms to Plural Terms is a good article for the use of singular and plural endings. This article will begin with a review of the basic prefixes and suffixes that can be used for all body systems.
Review of Prefixes
This section contains prefixes that are used for the medical terminology of most systems.
Prefixes are used at the beginning of a word to modify or vary the meaning of the word. When the prefixes are detached from a term, it is followed by a hyphen (-).
| Prefixes | Definition |
|---|---|
| a-, an- | no, not, without, away |
| aut- | self |
| brady- | slow |
| dia- | apart, through |
| end-, endo- | within, inside |
| exo- | outside of, without |
| epi- | above |
| hyper- | excessive |
| hypo- | insufficient |
| inter- | between |
| intra- | middle |
| media- | medium |
| medial- | situated or pertaining to the middle |
| medi- | middle |
| medio- | within |
| normo- | normal |
| per- | through |
| peri- | around |
| physio-, physi- | related to nature or physiology |
| poly- | many |
| pro- | before, for, in front of, from, in behalf of, on account of |
| re- | back, again |
| retro- | behind, back, backward |
| sub- | under, below, beneath, in small quantity, less than normal |
| syn-, sy-, syl-, sym- | union or association |
| tachy- | fast |
| trans- | across, through, beyond, over |
| ultra- | excess |
Review of Suffixes
Below are some suffixes that can be used for the medical terminology of most systems.
Suffixes are placed at the end of a word root or word part to modify or vary the meaning. Suffixes can indicate a condition, disease or procedure. When a suffix is written detached it is preceded by a hyphen (-).
| Suffixes | Definition |
|---|---|
| -ac. -al, -ar, -ary | Pertaining to |
| -ic | Pertaining to, characteristics |
| -ose, -ous | Pertaining to |
| -tic | Pertaining to |
| -centesis | surgical puncture as to aspirate or remove fluid |
| -cision | process of cutting |
| -ectomy | excision (surgical removal or cutting out) |
| -gram | a drawing or a written record |
| -graph | product of a drawing, writing or recording |
| -graphy | the process of recording |
| -ia | condition |
| -ism | condition process, theory of, principle, method |
| -itis | inflammation |
| -ologist | one who studies |
| -ology | study of |
| -lysis | process of loosening, freeing, or destroying |
| -opsy | to view |
| -osis | condition, status process |
| -otomy | cutting into |
| -ostomy | formation of an opening |
| -plasty | surgical repair |
| -pathy | disease |
| -sclerosis | hardening |
| -scope | instrument for viewing |
| -scopy | visual examination with a lighted instrument |
| -sis | state of, condition |
| -stasis | to stand, place, stop, control |
| -stenosis | narrowing |
| -tension | pressure |
| -therapy | treatment |
| -thoracic | chest |
| -ule | small |
Word Root and Combining Vowel for the Musculoskeletal System
This is a list of word roots with their combining vowels used for the integumentary system.
| Term | Definition |
|---|---|
| Cerebell/o | cerebellum |
| Cerebr/o | cerebrum |
| Cephal/o | head |
| Crani/o | skull or cranium |
| Encephal/o | brain |
| Gangli/o | ganglion |
| Medul/o | medulla oblongata |
| Myel/o | spinal cord |
| Neur/o | nerve |
| Spin/o | spine |
| -crania | head or skull |
| -cerebral | brain |
| Dendr- | branches |
| Caud- | tail bone |
| Equin- | horse |
Neurological Specialties
This is a list of specialists that diagnose and treat conditions related to the nervous system.
| Term | Definition |
|---|---|
| Neurology | Neuro- means nerve. |
| -ology is the study of. | |
| Neurology is a medical specialty that treats conditions related to the nervous system. | |
| Neurologist | Neuro- means nerve. |
| -logist means one who studies. | |
| A neurologist is a person who treats conditions related to the nervous system. | |
| Neurosurgeon | Neuro- means nerve. |
| Surgeon means a physician that treats deformities, injuries and diseases using operative procedures. | |
| A neurosurgeon is a physician that specializes in the nervous system and operative procedures. |
The Structure and Functions of the Nervous System
| Term | Definition |
|---|---|
| Action potential | Action is motion or activity used to produce a reaction. |
| Potential is an interpretation of energy involved in passing on a unit of electric charge. | |
| Action potential is an electrical impulse transmitted across a plasma membrane or nerve fiber. The action potential moves from neuron to neuron in an electrical synapse thereby allowing an electrical current to flow between neurons. | |
| Afferent neuron | Afferent means moving toward the center. |
| Neurons receive information and transmit messages from one cell to another, throughout the body. | |
| Afferent neurons (also called sensory neurons or input neurons) carry impulses from the peripheral receptors (skin and sensory organs) to the central nervous system (spinal cord and the brain). | |
| Afferent pathways (ascending pathways) | Afferent is moving toward the center. |
| Pathways are routes taken. | |
| Afferent pathways are the routes taken from the periphery of the body to the central nervous system. | |
| Anterior horn | Anterior means pertaining to the front. |
| Anterior horn is a horn-like projection of gray matter into the white matter of the spinal cord. | |
| Autonomic nervous system (ANS) | The autonomic nervous system provides the nerves to the parts of the body that is involuntary and not under conscious control. The autonomic nervous system is also responsible for maintaining a stable internal environment. It regulates cardiac muscle, smooth muscle, and the glands of the body. |
| Arachnoid space | Arachnoid means resembling a spider web. |
| The arachnoid space is a delicate middle layer that follows the same contours as the dura mater in the brain. This space lies between the dura mater and the pia mater. | |
| Axons | Axons are the long projections of the cell body that carry the nerve impulses away from the cell body. |
| Basal ganglia | Basal refers to fundamental or basic. |
| Ganglia or ganglion refers to a knotted mass of nerve tissue. | |
| The basal ganglia are the sections of gray matter containing cell bodies within the cerebral hemisphere. | |
| Blood brain barrier | The blood brain barrier is a characteristic of the brain located within the central nervous system. It consists of a wall of capillaries which prevents or slows the passage of some drugs, chemical compounds and organism that can cause disease of the central nervous system. |
| Brachial plexus | Brachial refers to the arm. |
| Plexus refers to a network of nerves and blood vessels. | |
| The brachial plexus is a network of nerves and blood vessels that animate the upper limbs. | |
| Brain | The brain is the portion of the central nervous system located within the cranium which is responsible for a person’s intelligence, personality, reasoning, and their mood. It also allows a person to interact with their environment. |
| Brainstem | The brainstem is a stalk-like structure that is below and partially covered by the cerebrum. The brainstem divides into the medulla oblongata, the pons, and the mesencephalon. The brainstem is responsible for motor, reflex and sensory functions. |
| Cauda equina | Caud- refers to tail, or toward the tail bone. |
| Equin- refers to characteristics of a horse. | |
| The cauda equina is a group of spinal nerves at the lower end of the spinal cord beginning at the lumbar to the coccygeal nerves. | |
| Cell body | Cell is the fundamental unit of tissue. |
| Body is the main portion of a structure. | |
| The cell body contains a nucleus and controls the function of the cell which includes cell metabolism. | |
| Central nervous system (CNS) | The central nervous system controls all the functions of the body. It consists of the brain and spinal cord, motor pathways, protective structures, and blood supply. |
| Cerebellum | Cerebellar refers to the cerebellum. |
| The cerebellum, located posterior to the brainstem, plays an important role in sensory and motor coordination and also balance. | |
| Cerebral cortex | Cerebral refers to the brain. |
| Cortex refers to the outer layer of a structure. | |
| The cerebral cortex is a layer of neurons and synapses on the surface of the cerebral hemisphere. | |
| Cerebral hemisphere | Cerebral refers to the brain. |
| Hemisphere is half of a sphere. | |
| The cerebral hemisphere is one half of the cerebrum. There are two cerebral hemispheres divided by a longitudinal fissure. | |
| Cerebrospinal fluid (CSF) | Cerebrospinal refers to the brain and spinal cord. |
| The cerebrospinal fluid is a clear fluid that bathes the brain and spinal cord. The cerebrospinal fluid also acts as a shock absorber protecting the structures from blows. | |
| Cerebrum | Cerebr/o means cerebrum. |
| -cerebral means brain. | |
| The cerebrum is the largest part of the brain. | |
| Circle of Willis | The circle of Willis is a network formed by the anterior, posterior and middle cerebral arteries. The anterior and posterior communicating arteries offer collateral blood flow when a primary artery is obstructed. |
| Cranial nerve | The cranial nerves are the 12 pairs of nerves emerging from the cranial cavity through various openings in the skull. |
| Dendrites | Dendr- refers to branches. |
| The dendrites are the thin branch-like fibers of the cell. The dendrites receive neurotransmitters released from other neurons. | |
| Diencephalon | The diencephalon is the portion of the brain between the cerebrum and the mesoencephalon. It consists of the hypothalamus, thalamus, metathalamus, and the epithalamus and includes most of the third ventricle. |
| Dorsal horn | Dorsal refers to back or posterior |
| The dorsal horn is the horn shaped projection of gray matter in the posterior region of the spinal cord. | |
| Dura mater | The dura mater is the thick tissue that lines the inside of the skull. |
| Efferent neuron | Efferent means away from the center. |
| Efferent neurons (also called motor neurons or output neurons) carry and transmit impulses from the central nervous system (brain and spinal cord) to muscles and glands. | |
| Efferent pathways (descending pathways) | Efferent means away from the center. |
| Pathways are routes taken. | |
| Efferent pathways are the route of the nerve fibers carrying impulses away from a nerve center. | |
| Epidural space | Epidural means above the dura mater. |
| The epidural space is the space immediately above and surrounding the dura mater of the brain or spinal cord. | |
| Fascicles | The fascicles individual bundles of nerves. |
| Fissure | A fissure is a deep depression on the surface of an organ such as the brain. |
| Frontal lobe | Frontal means front. |
| Lobe means rounded projection. | |
| The frontal lobe is the largest of the five lobes of the cerebrum that is responsible for voluntary control of the skeletal muscle, thought and speech. | |
| Glial cells | The glial cells (neuroglia) are specialized cells of the nervous tissue. These cells are the support cells of the nervous system. |
| Gray matter | Gray matter is the gray nervous tissue found in the brain and spinal cord. |
| Interneurons | Interneurons carry information between neurons. |
| Lateral horn | Lateral refers to the side. |
| The lateral horn is a small horn-like projection of gray matter into the white matter of the spinal cord between the anterior and dorsal horn. | |
| Longitudinal fissure | Longitudinal refers to the measurement of the long axis of an object. |
| Fissure refers to a deep depression on the surface of an organ such as the brain. | |
| A longitudinal fissure is the largest and deepest depressions between the cerebral hemisphere. | |
| Lumbar plexus | Lumbar refers to the area between the thorax and pelvis. |
| Plexus refers to a network of nerves and blood vessels. | |
| Lumbar plexus is a network of nerves located on the inside of the posterior abdominal wall. | |
| Medulla oblongata | Medulla refers to the internal portion of a structure. |
| The medulla oblongata is the lowest portion of the brainstem. It is continuous with the spinal cord. | |
| Meninges | Meningo- means membranes covering the brain and spinal cord. |
| Meninges are the membranes which encompass the brain and the spinal cord. The meninges include the dura mater, the pia mater, and the arachnoid membrane. | |
| Midbrain | The midbrain is the most superior portion of the brainstem. |
| Motor neuron | Motor refers to motion. |
| Motor neurons are nerve cells that transmit nerve impulses from the brain or spinal cord to muscular tissue. | |
| Myelin sheath | A Myelin sheath is a segmented fatty sheath that wraps the axon of many neurons in the body. |
| Neuromuscular junction | Neuromuscular refers to nerve and muscle. |
| Neuromuscular junction is the area of contact between the ends of a nerve fiber and the skeletal muscle. | |
| Neurons | Neurons control all the functions of the nervous system. |
| Neurotransmitters | Neuro- refers to nerves. |
| Neurotransmitters are chemical messengers that carry a signal from one neuron across the synaptic cleft to the next neuron. | |
| Nodes of Ranvier | Node refers to a small round mass. |
| Nodes of Ranvier are the gaps along myelin sheath that facilitate the transmission of impulses. | |
| Occipital lobe | Occipital refers to the back of the head. |
| Lobe means rounded projection. | |
| The occipital lobe is one of the four lobes of each cerebral hemisphere located behind the parietal and temporal lobes. | |
| Parasympathetic nervous system | The parasympathetic nervous system is responsible for the conservation and restoration of energy stores. It also helps the body return back to normal from a sympathetic response. This branch of the nervous system is mediated by acetylcholine. |
| Parietal lobe | Parietal refers to the parietal bone. |
| Lobe means rounded projection. | |
| The parietal lobe is the portion of the cerebral hemisphere that is posterior to the frontal lobe. The parietal lobes are responsible for language and sensory functions. | |
| Peripheral nervous system (PNS) | Peripheral refers to away from the center. |
| The peripheral nervous system contains the cranial nerves and spinal nerves outside the brain and spinal cord. | |
| Pia mater | The pia mater is the innermost layer of the three meninges. This layer covers the surface of the brain and spinal cord. |
| Plexus | A plexus is a network of intersecting nerves and blood vessels. |
| Pons | The pons, which is an area of the brainstem just above to the medulla oblongata, relay nerve impulses to and from the body to the cerebellum. |
| Receptors | A chemical structure on the surface of a cell that is sensitive to stimulation. |
| Reticular activating system (RAS) | Reticular refers to having an interwoven structure. |
| The reticular activating system is a network of nerve cell bodies in the brainstem responsible for maintaining a wakeful state. | |
| Sacral plexus | Sacral refers to sacrum. |
| Plexus refers to a network of nerves and blood vessels. | |
| The sacral plexus is a network of motor and sensory nerves that originate from the sacral spine which innervates the lower trunk and legs. | |
| Schwann cells | Schwann cells are cells that form the myelin sheath around the peripheral nerve fibers. |
| Sensory neuron | Sensory refers to sensation. |
| Sensory neurons are nerve cells that conduct sensory impulses from the periphery of the body to the brain or spinal cord. | |
| Somatic nervous system (SNS) | Somatic refers to body. |
| The somatic nervous system regulates voluntary motor control and provides sensory input for the nervous system. | |
| Spinal cord | Spinal refers to the spine. |
| The spinal cord is located in a cylindrical structure that is inside the vertebral column. It allows nerve impulses to travel to and from the brain. | |
| Spinal nerve | Spinal refers to the spine. |
| The spinal nerves are the 31 pairs of nerves that are connected to the spinal cord and numbered according to the level at which they emerge out of the vertebral column. | |
| Subdural space | The subdural space is below the dura mater and above the arachnoid space. |
| Sulcus | The sulcus is a shallow depression on the surface of the brain or an organ |
| Sympathetic nervous system | Sympathetic refers to a division of the nervous system. |
| The sympathetic nervous system controls the fight-or-flight response. | |
| Synapse | The synapse is the area between two neurons at which nerve impulses are transmitted. |
| Temporal lobe | Temporal refers to the temporal bone of the skull. |
| Lobe means rounded projection. | |
| The temporal lobes are the lateral regions of the cerebral hemispheres. | |
| Ventricles | Ventricles are the cavities within the brain that are filled with cerebrospinal fluid. |
| Wernicke center | The Wernicke center is a section of the posterior temporal lobe where the sensory speech center is located. |
| White matter | White mater is tissue of the central nervous system which mainly consists of myelinated nerve fibers and has an almost white color. |
Procedures of the Nervous System
| Term | Definition |
|---|---|
| Cerebrospinal Fluid Analysis (Lumbar puncture) | Cerebrospinal refers to the brain and spinal cord. |
| For a cerebrospinal fluid analysis, cerebrospinal fluid is aspirated by needle insertion between the l3-l4 or l4- l5 intervertebral spaces. This procedure assesses for different central nervous system diseases. | |
| Cerebral Angiography | Cerebral refers to the brain. |
| Angio refers to a vessel. | |
| -graphy is the process of recording. | |
| A cerebral angiography uses serial x-rays to visualize intra and extra cranial blood vessels. This procedure is used to detect vascular lesions and tumors. | |
| Computed Tomography (CT scan) | A computed tomography is a technique that uses radiography to produce an image of the cross section of tissue. |
| Craniectomy | Crani- refers to the skull or head. |
| -ectomy refers to an excision (surgical removal or cutting out). | |
| A craniectomy is a surgical procedure which involves the removal of a portion of the skull. | |
| Craniotomy | Crani refers to skull or head. |
| -otomy refers to cutting into. | |
| A craniotomy is a surgical procedure which involves entry into the skull. This procedure is usually done to relieve intracranial pressure. | |
| Electroencephalography (EEG) | Electro- refers to electrical. |
| Encephalo refers to the brain. | |
| -graphy is the process of recording. | |
| During this procedure electrical activity of the brain is recorded by scalp electrodes to evaluate seizure disorders, cerebral disease, and brain death. | |
| Electromyography (EMG) | Electro- refers to electrical. |
| Myo- refers to muscle. | |
| -graphy is the process of recording. | |
| During this procedure needle electrodes are inserted to record activity associated with a nerve or skeletal muscle to detect muscle and peripheral nerve disease. | |
| Magnetic Resonance Imaging (MRI) | Magnetic refers to lodestone. |
| Resonance means to sound again. | |
| Imaging means image. | |
| An MRI is a procedure used to produce an image by the creation of a magnetic field to give detailed information about nervous system abnormalities. | |
| Magnetic Resonance Spectroscopy (MRS) | Magnetic refers to lodestone. |
| Resonance means to sound again. | |
| Spectro refers to relationship of an image or spectrum. | |
| -scopy is the visual examination with a lighted instrument. | |
| A magnetic resonance spectroscopy provides information about the chemical composition of tissue by measuring wavelength of rays in a spectrum. It is used to study disorders of the nervous system including brain diseases, brain tumors, Alzheimer’s disease, strokes, seizure disorders and multiple sclerosis. | |
| Myelography | Myelo refers to spinal cord. |
| -graphy is the process of recording. | |
| During a myelography, a contrast medium is injected into the subarachnoid space and an x-ray of the spinal cord and vertebral column is performed. It is used to detect for spinal lesions. | |
| Positron emission tomography (PET scan) | Positron is a positively charged particle. |
| Emission is something that is emitted. | |
| Tomography is a sectional imaging. | |
| A positron emission tomography uses a radioactive material (drug) that shows up as a bright spot on an image. It measure metabolic activity of the brain to assess cell death or damage. | |
| Ventriculostomy | Ventricul- refers to the ventricle. |
| -ostomy is the formation of an opening. | |
| During a ventriculostomy an opening is formed in the skull and a catheter is placed in one or the lateral ventricles of the brain. This catheter is used to measure intracranial pressure and allow for drainage of fluid to relieve intracranial pressure. |
Diseases and Disorders of the Nervous System
| Term | Definition |
|---|---|
| Altered level of consciousness (LOC) | A patient has an altered level of consciousness when they are not oriented, do not follow commands, or needs persistent stimuli to achieve a state of alertness. |
| Agnosia | Agnosia is the loss of ability to recognize objects. This may be through a visual, auditory, or tactile sensory system. |
| Aneurysm | An aneurysm is a weakening or bulge in the wall of a blood vessel. |
| Aphasia | Aphasia is an inability to express words or form words and to understand language. |
| Apraxia | Apraxia is an inability to perform purposeful acts such as the manipulation of objects on a voluntary basis. |
| Ataxia | Ataxia is impaired coordination of movement marked by gait or postural imbalance. |
| Autonomic dysreflexia | Autonomic dysreflexia is a life threatening emergency in patients with spinal cord injury or lesions characterized by a hypertensive emergency. |
| Bell’s Palsy | Bell’s Palsy is a condition marked by unilateral weakness or paralysis of the facial muscles on the affected side. |
| Brain abscess | A brain abscess is a cluster of infectious material within a portion of the brain. |
| Brain death | Brain death is irreversible loss of all brain function even though the heart continues to beat. |
| Brain injury | A brain injury is an injury to the skull or brain such as a blow or penetrating object that is severe enough to interfere with normal functioning. |
| Cerebral edema | Cerebral edema is an abnormal accumulation fluid in the intracellular space, extracellular space, or both. |
| Coma | A coma is a prolonged state of unconsciousness characterized by the inability to arouse the person. |
| Concussion | A concussion is damage to the brain caused a by blow, shaking, jarring, a blast or some type of non-penetrating injury. There is temporary lose of neurological function with no apparent damage. |
| Contusion | A contusion is bruising due to bleeding of the underlying tissue of the brain surface caused by a blow in which the integrity of the skin is not disrupted but the blood vessel were ruptured. |
| Cushing’s triad | Cushing’s triad refers to three classic signs including bradycardia, hypertension, and bradypnea when there is pressure on the medulla usually due to herniation of the brain stem. |
| Decerebrate posture | Decerebrate posture is an abnormal body posture, usually in a comatose patient with a severe brain injury, in which the arms are extended and internally rotated and the lower extremities are extended with the feet in the plantar flexion position. |
| Decorticate posture | Decorticate posture is an abnormal body posture, usually in a comatose patient with a severe brain injury, in which the arms are abnormally flexed and the lower extremities are extended. |
| Dyskinesia | Dyskinesia is the impaired ability to execute voluntary movements. |
| Dysphagia | Dysphagia is difficulty swallowing. |
| Dysphonia | Dysphonia is difficulty speaking due to voice impairment or altered voice production. |
| Expressive aphasia | Expressive aphasia is the inability to express oneself; often associated with damage to the left frontal lobe area. |
| Epilepsy | Epilepsy is a neurological disorder characterized by paroxysmal transient disturbances of brain function, resulting in convulsions and loss of consciousness. |
| Guillain-Barre Syndrome | Guillain-Barre syndrome is an autoimmune disease which attacks the peripheral nerve myelin. |
| Head injury | A head injury is an injury to the scalp, skull, and or brain resulting from trauma. |
| Hemiparesis | Hemiparesis is weakness of one side of the body or part of it, due to an injury in the motor area of the brain. |
| Hemiplegia | Hemiplegia is paralysis of one side of the body, or part of it, due to injury in the motor area of the brain. |
| Intracranial pressure (ICP) | Intracranial pressure is pressure exerted by the volume of the intracranial contents within the cranium. |
| Meningitis | Meningitis is an inflammation of the meninges, the membrane which covers and protects the brain and spinal cord. |
| Multiple Sclerosis | Multiple sclerosis is an immune disease that causes the demyelination or destruction of the myelin sheath. |
| Myasthenia Gravis | Myasthenia Gravis is an autoimmune disorder affecting the neuromuscular junction, which causes muscle weakness. |
| Neuropathy | Neuropathy is the inflammation of the peripheral nerves which causes weakness or numbness. |
| Paraplegia | Paraplegia is paralysis of the lower extremities caused by spinal injury or disease. |
| Paresthesia | Paresthesia is the sensation of numbness or tingling, also known as a feeling of “pins and needles”. |
| Quadriplegia (Tetraplegia) | Quadriplegia also known as tetraplegia is paralysis of both arms and legs and the trunk resulting from spinal cord injury. |
| Seizures | Seizures are abnormal electrical activity of the brain resulting in involuntary contractions of muscle groups. |
| Spinal cord injury | A spinal cord injury is an injury to the spinal cord, vertebral column, and supporting soft tissue. |
| Status epilepticus | Status epilepticus is an occurrence of multiple seizures in which the patient does not experience recovery time in between seizures. |
| Transection | Transection is when the spinal cord is severed, either all the way through or partially. |
Reference
Mosby’s Medical Dictionary (2017). 10th ed. St Louis, MO. Elsevier Inc.
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