Common Word Roots for Nervous System (Part 2)

mening/o or meningi/o is a combining form that refers to "meninges". The meninges are three layers of membranes covering and protecting the brain and spinal cord (the central nervous system). The dura mater is the outer layer, closest to the skull. The arachnoid mater is the middle layer. The pia mater is the inner layer, located closest to brain tissue.

myel/o is a combining form that refers to "spinal cord". The spinal cord is a thin, long tube-like structure made up of nervous tissue, connecting from the brainstem to the lumbar region (backbone). Spinal cord functions include sending motor commands from the brain to the body, sending sensory information from the body to the brain, and coordinating reflexes.

narc /o is a combining form that refers to "stupor; numbness". A state of stupor; numbness is an altered mental state in which a person is only stimulated by intense or distressing stimuli.

neur/o or neur/i is a combining form that refers to "nervous system" or "nerve". Nervous system components include the brain, spinal cord, and nerve fibers. This system is responsible for sending and receiving messages both between the brain and the body. All body functions are managed by the brain. Down the back, the spinal cord extends from the brain.

phas/o is a combining form that refers to "speech". The capability to convey thoughts and emotions through vocal sounds and actions is called speech.

poli/o is a combining form that refers to "gray matter". Gray matter is a brain tissue which has a pinkish-gray color, is host to neural cell bodies, axon terminals, dendrites, and nerve synapses. A large amount of this brain tissue can be found in the cerebellum, cerebrum, and brain stem. Also, it is the part of the central spinal cord that is shaped like a butterfly. It is the gray matter that actually processes information while the white matter provides the communication between different gray matter areas.

psych/o or ment/o is a combining form that refers to "mind". The mind is the part of a person that is responsible for the ability to think, to experience emotions, and to be aware of things around them.

radic/o, radicul/o or rhiz/o is a combining form that refers to "nerve root". A nerve root is a branch that is located at the end of a spinal nerve, cranial nerve, or spinal nerve. Nerve roots come in two types: cranial and spinal. Movement and feeling are stimulated by spinal nerve roots. Cranial nerves send electrical signals from your brain to your face, neck, and torso. Senses such as taste, smell, hearing, and touch are also mediated by the cranial nerves.

somn/o or somn/i is a combining form that refers to "sleep". Sleep is a naturally recurring cycle of mind and body. It involves altered consciousness, reduced sensory activity, decreased muscle activity, and the inhibition of almost all voluntary muscles during rapid eye movement sleep. As a result of sleep, the body and mind are reenergized, allowing a person to wake up refreshed and alert.

thalam/o is a combining form that refers to "thalamus". The thalamus is a thick mass of gray matter situated in the back part of the diencephalon (part of the forebrain). The thalamus is the body's information relay center. Information from the senses (except smell) must be processed by the thalamus before it can be interpreted by the cerebral cortex. Additionally, the thalamus is involved in sleep, wakefulness, consciousness, memory and learning.