Difference Between White Matter and Gray Matter

White Matter vs Gray Matter

Both white matter and gray matter are terms that relate with the cells of the brain. A cross section of a brain will show these cells in their respective colours, and they are so named as white and gray matter. However, the two types of brain tissues become white and gray after being dipped in preservatives as the live colours are slightly different with the presence of blood. Gray and white matters are the two main types of brain cells and the functions of these vary from each other. Mainly, the processed signals by gray matter are being passed through white matter inside the brain.

White Matter

White matter is one of the two components of the brain that coordinate different regions of the brain. It is said that white matter of the brain is equivalent to the cables of a computer network. Even though the tissue is named as white, the live colour is pinkish white due to the presence of blood. The usual preservative, formaldehyde, makes the white matter to be white. Although it is stated here that white matter is present in the brain, there are also white matter tissues in other parts of the body associated with the nervous system such as the spinal cord, blood…etc.

白质既包含神经胶质细胞，又包含经常被髓鞘的长轴突。在大脑和脊柱白质中不存在树突，但没有神经元细胞体。大脑的大多数（60％）是由这个问题组成的，这对于在大脑区域之间传达脉冲非常重要。白质的量化主要是通过考虑组成神经元的总长度来完成的。男性的白质总长度超过175,000公里，而女性在20岁时拥有将近15万公里的白质细胞。随着人的年龄，这种长度以每年的10％的速度降低。根据它们所连接的区域，有三个主要区域或束白质。它们被称为投影（在较高和下部之间垂直连接），连接（在两个脑半球之间连接）和联合（连接同一脑半球的不同区域）。

Gray Matter (Grey Matter)

Gray matter is the most important component of the nervous system that is composed of regions of the brain responsible for sensory perception, memory, emotions, speech, and for almost all the muscle control. Gray matter is composed of neuronal cell bodies, glial cells, and capillaries. However, the presence of the nuropil, which is composed of unmyelinated axons and dendrites, is very important to notice. It would also be important to state that most of the neurones are myelinated in gray matter except in the nuropil. The live gray matter is mainly brownish-grey in colour due to the presence of blood capillaries and neuronal cell bodies. It is very difficult to understand the mechanisms of sensory processes taking place in different regions of gray matter, yet the scientists have identified the main regions involved in hearing, seeing, muscle controlling, thinking, and speaking. Therefore, gray matter has been sometimes referred as a set of computers with different specialities.

What is the difference between White Matter and Gray Matter?

• The basic colourations of both tissues have been the basis for the naming, and their colours can be considered to distinguish the two.

• Gray matter forms the processing units of sensory function while white matter forms the connections among gray matter units.

• The white matter is slightly more prominent (60%) than gray matter (40%) in the quantity.

• Cells of the white matter are longer than gray matter cells.

• The total length of white matter lessens with age, but gray matter does not dwindle significantly.