We explain what the central nervous system is and what its functions are. Also, what are neurons and their structure.
What is the central nervous system?
The central nervous system (CNS) is a complex structure that is present in humans and animals and that has the function of coordinating, integrating and controlling the body.
It is made up of the brain (located in the skull) and the spinal cord (located within and along the entire spinal column) and is what allows you to perform functions such as movement, learning, breathing, among many others.
The central nervous system receives information, from external or internal stimuli, which it processes through cells called neurons and elaborates responses. Too takes care of the organization of the different devices, such as respiratory or digestive.
Together with the peripheral nervous system, the central nervous system forms the nervous system of organisms. The peripheral nervous system has the function of transporting stimuli from the senses to the central nervous system.
Neurons
Neurons are cells that are part of the nervous system of organisms and they have the function of receiving, processing and transmitting information through nerve impulses. These cells connect to each other and allow information to travel from one part of the body to another.
The process of connection between neurons is known as synapse and it uses neurotransmitters, which are chemical substances that allow the transmission of nerve impulses between one neuron and another.
Neurons have a shape that differs from traditional cells in that are made up of a soma or body. This soma has a rounded shape and is covered with hairs called dendrites, which are nerve centers that receive information from other neurons.
An axon emerges from the soma, which is a long, thin connection that allows information to travel. The information that leaves the axon reaches the dendrites of another neuron, which receives it, processes it in its soma and sends it through its axon to the dendrites of another neuron.
The distinctive characteristic of neurons is that information travels extremely fast, through nerve impulses, thanks to the myelin that covers the axon.
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Structure of the central nervous system
The central nervous system it is subdivided into two parts: one that is inside the skull (the brain) and the other inside the spinal column (the spinal cord).
- Brain. It is an organ that is part of the central nervous system and is located in the cerebral cortex. It is responsible for regulating most vital functions such as appetite, vision, emotions, thinking, among others. In humans and vertebrates, the brain is divided into:
- Anterior brain. It is also called a forebrain.
- Middle brain. It is also called the midbrain and is the upper structure of the brain stem.
- Posterior brain. It is also known as the rhombencephalon and is located in the upper part of the spinal cord. In turn, it can be subdivided into three parts:
- Bulb
- Annular protuberance
- Cerebellum
- Spinal cord. It is a nervous tissue that has a flattened, cylindrical structure and that extends from the base of the skull to almost the end of the spinal column.
The spinal cord carries nerve impulses to the spinal or spinal nerves, that is, its function is to communicate the brain with the rest of the body. Therefore, the spinal cord sends information from the brain to, for example, the muscles, or from the muscles to the brain. It is also in charge of executing the reflex acts.
Central nervous system functions
The central nervous system is the one in charge of regulating all the activities carried out within the body and process the information that enters from the senses.
This involves the development of ideas, thoughts, memories, emotions. What’s more, regulates and sends the signal that activates the movements of the body, sleep, wakefulness, the functioning of organs such as the heart, functions such as eating, drinking, among many others.
The highest level in the central nervous system is the one in the cerebral cortex. Higher functions such as conscious perception are organized in the cortex, memory, language and reasoning. Then there are the cerebellum and the basal ganglia, which are in charge of consciously controlling movement.
For its part, the brain stem is in charge of involuntary functions such as maintaining balance, controlling the pressure in the body, executing automatic movements such as breathing or heartbeat, chewing, among others.
Then there are the functions carried out by the spinal cord, which are:
- Afferent functions. Its function is to transmit the sensations of the trunk, neck and four limbs to the brain.
- Efferent functions. They are the orders that start from the brain to the medulla, which is the one who tells the different organs to carry out a certain action.
Importance of the central nervous system
The central nervous system is a vital structure for the proper development of organisms. It is through it that the individual connects and relates to the environment that surrounds him, since he receives the stimuli (which he captures through the senses) and the central nervous system is in charge of interpreting them and giving the signal for the execution of a response .
In addition, the central nervous system regulates voluntary and involuntary processes that occur in the body and that they are those that allow the correct balance and development, such as respiration, digestion or movement. A disorder in any of the areas involved in the nervous system implies an alteration in its proper functioning.
To keep a nervous system in balance, it is important to take care of the state of neurons, which are cells that disappear over time, although they can regenerate (neurogenesis). Good nutrition, rest and physical activity protect neurons from early deterioration.
Central nervous system diseases
There are certain diseases and pathologies that can affect the correct performance of the central nervous system. Some are:
- Epilepsy. Central nervous system disorder in which mental activity is impaired, leading to seizures.
- Amyotrophic Lateral Sclerosis. A disorder in which neurons are wasted or lost, reducing or paralyzing muscle activity.
- Multiple sclerosis. A disorder in which the protective layer that covers the nerves breaks down, making it difficult for the brain to connect with the rest of the body.
- Monoplegia. A type of brain disorder that occurs when part of the central nervous system is injured, causing a connection problem and affecting muscle movement. In monoplegia, one limb of the body is affected.
- Hemiplegia. A type of brain disorder that occurs when part of the central nervous system is injured, causing a connection problem and affecting muscle movement. In hemiplegia, one side of the body is affected.
- Tetraplegia. A type of brain disorder that occurs when part of the central nervous system is injured, causing a connection problem and affecting muscle movement. In tetraplegia, both arms and both legs are affected.
- Parkinson’s disease. A disorder of the central nervous system that causes tremors and affects movement.
- Alzheimer disease. Disorder in which neurons degenerate which produces alterations in memory and language.
- Huntington’s disease. Disorder in which neurons degenerate which causes alterations in movements and cognitive damage.
- Meningitis. An infection that occurs when a virus or bacteria attack the membranes of the spinal cord and brain. This causes malaise, fever, and neck and back pain.