O nervous system is the system responsible for capture, process and generate responses before the stimuli to which we are submitted. It is due to the presence of this system that we are able to feel and react to different changes that occur around us and even inside our body.
He can be Divided in two servings:
• Central nervous system: formed by the brain and spinal cord.
• Peripheral nervous system: formed by the nerves, ganglia and nerve endings.
The nervous system is made up of a special type of tissue called tnervous acid, which has as cell types youneuronsand the callsglial cells.
You neurons are responsible for the propagation of the nervous impulse and present as basic parts the cell bodyr, where the nucleus is located, and two types of extensions, the axons and the dendrites. According to the function performed, neurons can be classified into two basic groups: sensitive or afferent (take impulses to the nervous system) and motors or efferents (take impulses to other parts, like muscles and glands).
Neurons ensure the transmission of the nerve impulse.
The group of cells called glial cells it is related to several functions, such as nutrition and regulation of the functioning of neurons. Ependymal cells, astrocytes, oligodendrocytes, microglia and Schwann cells they are glial cells.
→ central nervous system
The central nervous system is made up of the brain and spinal cord.
O central nervous system it is the part of the nervous system that guarantees the Front desk and the interpretation From stimuli, which can be considered the information processing center of our body. The constituents of the central nervous system are the spinal cord it's the brain.
In the central nervous system, the so-called white and gray substances. The white substance corresponds to the neuron axons, while the gray matter corresponds to the cell bodies. In the brain, in general, with the exception of the medulla, the gray matter is located more externally. In the medulla, in turn, the opposite is observed, with the white matter located more externally.
The central nervous system is protected by bones and membranes. The brain, for example, is protected by skull box, while the spinal cord is protected by the spine. Both the brain and the medulla are surrounded by three membranes called the meninges. The meninges are:
Dura mater: outermost and also the most fibrous.
Arachnoid: located between the dura and the pia mater. It receives this name because, when viewed under a microscope, it has the appearance of a spider's web. In subarachnoid space, it is found cerebrospinal fluid, which also features, among other functions, the protection function.
Pia mater: more internal and highly vascularized.
Spinal cord
THE spinal cord, also called the spinal cord, is a shaped structure. cylindrical which is located in the inner spine. In this structure, there is the white matter located more externally and the central gray matter forming the letter H.
The spinal cord is related to the reflex act, which is characterized by being a quick and involuntary response when faced with some stimulus, such as removing your hand when touching a hot plate. In these reflexes the brain is not involved, which means that the spinal cord can act as a independently. The reflex act is basically constituted by two types of neurons, a afferent it is a efferent.
brain
the brain is located inside the skull box and features several parts. Next, we'll describe the main brain structuresand some activities performed by them:
Brain stem: is formed by midbrain, pons and bulb. O midbrain it is related to hearing, visual reflexes and traction movement. THE bridge, as the name suggests, is related to the connection between various parts of the brain. O bulb it is related to the control of several functions, such as heartbeat, breathing and swallowing.
Cerebellum: it is mainly related to the coordination of movements and the balance of our body.
Diencephalon: consists of the thalamus, hypothalamus and epithalamus. O thalamus it is responsible for ensuring that sensory impulses reach the brain. O hypothalamus, in turn, it is related to several functions, such as water regulation, body temperature, hunger control, among others. This portion of the brain also acts producing hormones. O epithalamus includes the pineal gland, which is responsible for producing melatonin.
Brain: is the most developed portion of our brain and is divided into two portions: the left and right hemispheres. These two hemispheres are joined by the so-called corpus callosum. Our brain is responsible for ensuring motor activities, memory, intelligence, emotion and reason.
Read too:Uses of melatonin
→ Peripheral Nervous System
The peripheral nervous system is made up of nerves, ganglia and nerve endings.
O peripheral nervous system guarantees the transmission of information From Sensory organs to nervous system and gave it to the muscles, at glands and the endocrine cells.The neurons responsible for carrying information to the central nervous system are called afferents, and those that carry instructions to structures, after processing the stimulus in the central nervous system, are called efferent.
The peripheral nervous system is made up of the nerves, nodes and nerve endings. Nerves are nerve fibers grouped into bundles, whereas ganglia are accumulations of neurons that lie outside the central nervous system.
Nerves may protrude from the spinal cord or from the brain. the spinal nerves are those that protrude from the medulla, while the cranial nerves innervate from the brain. They exist 31 pairs of spinal nerves and 12 pairs of cranial nerves.
Law also: 12 pairs of cranial nerves
Autonomic Nervous System
The autonomic nervous system is a peripheral nervous system component what acts regulating some involuntary functions of our body, such as actions performed by systems respiratory, digestive, endocrine and cardiovascular.
In it there are the divisions nice and parasympathetic, which usually have antagonistic actions. The sympathetic division ensures, for example, that the heart beats faster in some stressful situation, while the parasympathetic makes the body relax after this situation.
Note some of the actions performed by the parasympathetic split and the sympathetic split.
Know more:Risks of synthetic drugs, understand how they act on the nervous system
→ Summary
The nervous system ensures that stimuli are captured and interpreted, and that responses to these stimuli are generated.
The nervous system is made up of nervous tissue.
The nervous system can be divided into the central nervous system and the peripheral nervous system.
The central nervous system is made up of the brain and spinal cord.
The peripheral nervous system is made up of the ganglia and nerves.
The autonomic nervous system has two divisions, the parasympathetic and the sympathetic.
By Ma. Vanessa Santos
Source: Brazil School - https://brasilescola.uol.com.br/biologia/sistema-nervoso.htm