What is grey matter

About , people in the U. These injuries affect one of the most complicated and mysterious areas of the body—an area that many injury survivors knew little about prior to their accident. Knowing the basics of central nervous system anatomy can help you better understand the information your doctor provides, empowering you to be a better advocate for yourself or a loved one. A lot of confusion revolves around the distinction between gray and white matter in the brain, but the difference is actually a pretty simple one.

Gray matter, named for its pinkish-gray color, is home to neural cell bodies, axon terminals, and dendrites, as well as all nerve synapses. This brain tissue is abundant in the cerebellum, cerebrum, and brain stem. It also forms a butterfly-shaped portion of the central spinal cord. The back portion of this butterfly shape is known as the posterior, sometimes called the dorsal gray horn.

This region passes sensory information via ascending nerve signals to the brain. The front part, which is sometimes called the ventral gray horn, sends descending nerve signals governing motor activities to your autonomic nerves.

A problem with the dorsal gray horn may affect your brain's ability to interpret sensory information, while issues with the ventral gray horn interfere with your body's ability to receive motor information; paralysis, tingling, and muscle weakness are often the products of damage to the ventral gray horn. The white matter of your brain and spinal cord is composed of bundles of axons. Specifically, the frontal lobes play functional roles in voluntary behavior such as decision-making, problem-solving, and thinking.

Similarly, it is essential for cognition, intelligence, attention, and voluntary motor control. The parietal lobes have associated functions in perception and the integration of somatosensory information, visuospatial processing, spatial attention, spatial mapping, and number representation.

Temporal lobes are essential for functions such as the comprehension of language, perception through hearing, vision, and smell, recognition, learning and memory. Within the cerebral cortex, there are also specific sensory and motor areas. These include the primary motor cortex and premotor cortex which regulate voluntary movement, the visual cortex of the occipital lobe which processes visual information, and the somatosensory cortex of the parietal lobe which processes tactile information such as touch, pressure, temperature, and pain.

The grey matter in the cerebellum is related to motor control, balance, coordination, and automatic movements. The three sections of grey matter in the spinal cord all also serve their own functions. The anterior grey column in the spinal cord is important for all motor movements as it connects to the brain through a pathway called the pyramidal tract which originates in the cerebral cortex.

The posterior grey column of the spinal cord plays an important function in receiving sensory signals, allowing for the constant interaction between the environment and the body. The posterior grey column is located proximate to the surface of the spine which makes it easier for nerves to send signals. The lateral grey column of the spinal cord, which is found in the middle of the grey matter of the spinal cord, is important for regulating the autonomic nervous system through its role in activating the sympathetic nervous system.

As grey matter covers many areas of the central nervous system and is the outermost layer to the brain specifically, this makes it susceptible to being damaged.

One of the most prevalent medical problems involving grey matter occurs when there is a plaque build up in one or more areas of the grey matter in the brain. This plaque takes up the space that would have been where there was once grey matter, meaning there would be a decrease in higher functioning as a result. Aside from a loss in cognitive functioning, grey matter decline can lead to motor function issues such as losing control of fine motor skills.

These diseases that cause a loss of neurons which make up the grey matter are called neurodegenerative diseases. Trauma to the central nervous system could also play a role in creating issues that stem from grey matter. As the cells in the grey matter require a constant high stream of oxygen to function normally, any trauma such as falling and hitting the head at force could cut off this supply of oxygen. If there is no oxygen reaching the grey matter, this can cause the cells to die and result in irreversible brain damage and loss of function.

Damage to the cerebral cortex in general can result in a variety of symptoms depending on the area that damage occurs. Damage to the parietal lobe could result in difficulties writing or being unable to write altogether, or an inability to discriminate between sensory information.

Damage to the temporal lobes may result in difficulties with comprehending speech, aggression, or memory loss. The gray matter is the areas where the actual "processing" is done whereas the white matter provides the communication between different gray matter areas and between the gray matter and the rest of the body.

The neurons in the gray matter consist of neuronal cell bodies and their dendrites. The dendrites are short protrusions that communicate with immediately neighboring neurons in the CNS. In contrast with the neurons of the white matter, gray matter neurons don't contain long axons that transmit the nerve impulses to more distant regions of the CNS. Gray matter is so-called because in section it has a gray color due to all the gray nuclei in the cells that make it up.

Gray matter involvement is detected even in the earliest stages of MS, and gray matter atrophy occurs at a faster rate than white matter atrophy early in the disease course. Gray matter involvement and in particular cortical demyelination can be extensive in MS. Gray matter pathology may occur in part independently of white matter lesion formation. A primarily gray matter-related process may be the earliest manifestation of MS.

Gray matter involvement is associated with physical disability, fatigue, and cognitive impairment in MS. Sign in with your library card Please enter your library card number. Related Content Related Overviews white matter cerebral cortex spinal cord cerebellum See all related overviews in Oxford Reference ». Show Summary Details Overview grey matter. Reference entries grey matter in Concise Medical Dictionary 8 Length: 59 words. All rights reserved. Sign in to annotate. Delete Cancel Save.