What is it and what does it consist of
White matter of the brain is a collective concept that refers to a complex of nerve structures through which electrical and chemical impulses are transmitted. The nerve cell can be thought of as a trading post where travelers sell and buy goods, relax and discuss prices. However, for successful commercial activities, traders need roads, thanks to which they make long journeys from one point to another, delivering valuable cargo. It’s the same in the brain: the white substance ensures the delivery of nerve impulses.
The white matter of the nervous system serves as a springboard for the gray matter. The latter, unlike white, acts as a generator and collector of information. The white substance transmits the nerve impulse and is not responsible for its creation. On the other hand, there are opinions of many experts that white matter determines the speed and quality of brain functioning, namely the number of formed nerve pathways. Indeed, the development of the mental component of the mental sphere in children usually means the formation of white matter in the brain.
The white substance is opposed to the gray one. Gray matter is a collection of nerve cell bodies and their appendages (glial tissue, capillaries, partially short processes and early axons). The functions of gray matter include providing programs for higher nervous activity, such as thinking, memory, and perception. The contrast is not only functional, but also anatomical. If the gray matter is the cortex (the final layer of the brain), then the white substance is located between the cortex and the deep structures of the brain.
Speaking of structure, the substantia alba differs from the gray matter: the white matter of the brain consists of bundles of long processes - axons, covered with a myelin sheath. This layer, consisting of fat components, provides a person with an electrical impulse transmission speed of up to 100 m/sec on average. An axon that does not have myelinated fibers transmits information up to 10 m/sec. The white color of the substance is provided by myelin, and on a section the subcortical ball of the substance looks whitish-cream.
So, the white matter of the brain is represented by myelinated axons that connect different parts of the brain. Anatomically, the processes are divided into long ones, responsible for communication between distant parts of the brain, and short ones, connecting nearby structures (brain convolutions). They are located as follows:
- Short . They lie directly under the cortex of the brain and are called subcortical.
- Long or intracortical. This part of the white matter is located in the deep parts.
In addition, white matter is conventionally divided into 3 types, depending on anatomical features:
Associative connections . Fibers of this type of white matter provide a general connection between areas of the cortex, but located in the same hemisphere. For example, association fibers connect the area of general sensitivity (parietal cortex) with the frontal cortex.
Commissural fibers . These structures are represented by cerebral adhesions and articulate similar areas, but on different hemispheres. For example, the hearing area on the temporal cortex of one hemisphere with the same area in the other part of the brain. The largest structure here is the corpus callosum. In the physiological aspect, the structure ensures the interconnection of both hemispheres. The corpus callosum has not been fully studied.
Projection fields . This type of white matter connects the cerebral cortex with structures morphologically located below. Functionally divided into two subtypes:
- Efferent fibers. Along these pathways, the nerve impulse is sent from the cortical centers to the underlying structures;
- afferent. These fibers ensure the delivery of electrical signals from underlying structures (internal organs, tissues) to the brain.
There are phenomena where people who do not have this unifying structure (corpus callosum) have phenomenal memory. Experts say that this is due to the corpus callosum, which acts as a kind of barrier that limits the flow of electrical impulses. In the case where it is not present, the areas are connected to each other directly, without any collector system or filters.
The white matter of the medulla oblongata is represented by short and long fibers. The latter include the pyramidal tracts running through the anterior clusters of the spinal cord. The fibers of the medulla oblongata form several tracts:
- Rubrospinal;
- Vestibulospinal;
- Reticulospinal tract.
Through these structures, information flows from the nuclei of the medulla oblongata, reticular and vestibular nuclei to the spinal cord.
The white matter of the midbrain forms a cluster represented by the cerebral body, located deep in the cerebellum. Branching, the fibers of the body pierce all the convolutions of the coordinating center of the brain. The fibers of the white matter of the cerebellum form pathways leading to the cerebral cortex and neighboring brainstem structures.
Brain damage
As a result of a skull injury, damage to the brain and therefore white matter can occur. Another cause is certain diseases that damage the forebrain. The development of pathology, depending on the location, causes paralysis of the muscular system on one side of the body. Such symptoms are typical when a part of the brain is damaged due to a stroke. Paralysis can be mixed, for example, the left half of the face and the right half of the body. White matter damage can impair visual field, swallowing, speech impairment, and many other symptoms. With Alzheimer's disease, the brain areas responsible for memory and recognition are affected, and mental disorders appear. Damage to certain areas of the brain can occur during intrauterine development of the fetus due to an infectious disease of the mother. In severe labor, the child is at risk from birth trauma, and in the first months of life, the threat is infectious diseases that lead to brain damage.
White matter functions
Primarily, the white matter of the brain is responsible for coordinating information in the central nervous system. Thanks to the white substance, the brain is capable of “communication” between its own areas. In addition to the brain, the substantia alba is also located in the spinal cord, but its set of functions in the periphery is different. The white matter of the spinal column is responsible for the sensory and motor components of nervous activity. White matter acts as a conductor. The white substance also provides:
- Connection of similar structures of the hemispheres;
- connection of various parts of the cerebral cortex with other parts of the nervous system, in particular with the spinal cord.
Prevention of operational disruptions
Physical activity, even in older people, affects the structure of white matter.
In addition, the load leads to densification of the white matter, which has a positive effect on increasing the speed of signal transmission.
A healthy lifestyle leads to improved brain function, which significantly improves the condition of the whole body. Intellectual activities along with physical activity, games in the fresh air, a variety of active recreation - all this will certainly help maintain memory and clarity of mind at any age.
The human brain contains white and gray matter of the hemispheres, which are necessary for the functioning of brain activity. We will look at what each of them is responsible for and what their fundamental differences are.
Difference from gray matter
Gray matter differs from white matter not only functionally, but also anatomically. Location: gray matter is located on the surface of the cerebral hemispheres and is its upper layer. The white matter is located between the gray and deep structures of the brain.
Structure
gray matter consists of soma neurocytes and its appendages
white matter consists of myelinated fibers
Function
gray nuclei are responsible for specific specific functions of the nervous system
White matter is a conductor of nerve impulses
To further understand the differential differences, you can go to the article difference between white matter and gray matter.
Physical exercise
According to recent studies by scientists from the United States, physical activity can have a positive effect on the structure of white matter, and therefore on the health of the entire brain as a whole. First, exercise helps increase blood flow to myelin fibers. Secondly, exercise makes your brain matter denser, which allows it to quickly transmit signals from one part of the brain to another. In addition, it has been scientifically proven that physical activity is beneficial for both children and older people to maintain brain health.
Preventative measures for brain health
The speed of nerve impulses directly depends on the integrity of the white matter. Its healthy state determines its normal functioning. It has been scientifically proven that with increasing age, the quality of white matter and its functionality decline. Therefore, you need to comply with some simple conditions:
- Exercise regularly at any age - from simple morning exercises to serious sports.
- Monitor your health and consult a doctor on time.
- If diseases that can cause brain damage occur, treat under the supervision of a doctor.
- Remove bad habits from your life that can worsen your health.
- Increase immunity using hardening procedures.
- Keep your emotional state under control.
- Give food for brain activity: read, write, solve crosswords and other puzzles.
- During pregnancy, be under constant supervision of a specialist.
An active physical life and intellectual pursuits in both work and leisure will prolong normal performance and clarity of mind, and maintain strong memory. Teach children to take their health seriously as early as possible. Play sports and games that develop intelligence. It’s good to work together, proving its usefulness by example.
Only humans have higher nervous activity, and this is their direct difference from other species of mammals. The conditioned reflex actions that he masters in the process of life put him at the highest level of development.
