Nervous System Development Stages and Factors

The nervous system is the main part of our body. We depend completely on it, so its correct training is essential for our quality of life, since from it ideas, behaviors and emotions are generated. There are various stages through which the formation of the nervous system passes. During the gestation period this system begins to form.

A bad nervous system development results in various diseases such as hydrocephalus or spine bifida. At the beginning of pregnancy three layers are formed, one of them is ectoderm, from which the nervous system is formed. The skin would also form from this layer.

Continue reading psychology-online to learn how the nervous system and each of its parts are formed. We will see continion The factors and stages of nervous system development, With the development of the embryonic nervous system per weeks.

1. Gastulation: First three weeks
2. Neural tube formation: third and fourth weeks
3. Differentiation of the parts of the central nervous system: fourth and fifth weeks
4. Cell differentiation: fourth and fifth weeks
5. Keep structures from: Sixth Week
6. Ganglia and vesicles: Sixth Week
7. Development of the fetus central nervous system
8. Baby and Child Nervous System Development

Gastulation: First three weeks

The first stage of the development of the embryonic nervous system occurs in the first weeks of gestation.

1. After fertilization, the initial cell or zygote is divided successively, to give rise to a structure formed by 16 cells called morula
2. The morula You can see about 4 days after fertilization.
3. Subsequently, these cells continue their division and begin to differentiate giving rise to a structure formed by a exterior spherical layer surrounding a space full of liquid.
4. From this moment, a very rapid series of changes will take germ layers (ectoderm, mesoderm and endoderm) What are the precursors of the different embryo tissues.
5. These transformations occur between the second and third week and give rise to Trilambar embryo From this moment on the embryo, it can also distinguish a region (rostral) and another flow (tail), a left side and another right and a dorsal surface (upper) and ventral (lower).

This moment is very important in the development of the nervous system, since around the third week of gestation begins its development.

Neural tube formation: third and fourth weeks

As we have seen, an elongated structure has been formed with three layers. In the outermost layer (ectodermo), and in dorsal position, a well -defined central longitudinal band is developed Neural plate, that extends from the cephalic region to the flow. This plate is the precursor of the nervous system, its cells will give rise to neurons and form the nerve tissue.

In the second phase of the development of the embryonic nervous system, the neural plate sinks or invasted inward. Both sides of the groove are delimited by the so -called neural folds; These are surrounding the channel until they join, which transforms the neural groove into a Hollow neural tube. This process takes approximately in the fourth week of development and begins in the central area of ​​the embryo, progressively extending to the rostral and flow.

Initially, the neural tube is open at its two ends but these openings disappear when the neural tube is completely formed (at the end of the fourth week). This closure of the two ends of the neural tube is very important Because if important anomalies are produced: so for example, if the flow end is properly closed. If the rostral end is incorrectly closed, malformations are produced in the brain (anencephaly) and in the skull, which is split. In relation to these processes, the importance of folic acid is known.

Differentiation of the parts of the central nervous system: fourth and fifth weeks

Between the dorsal ectoderm and the neural tube there is a group of pluripotential cells that form the call Neural crest which extends from the rostral zone to the flow along the body axis. Crest cells migrate in different directions and differ to give place to neurons and support cells of the peripheral nervous system. Its final differentiation is determined by the environment in which they will finally be developed after migration.

From the moment in which the rostral end of the neural tube closes a series of rapid transformations of the neural tube that lead to the formation of neural tube dilations begins in this area. These bumps constitute sketches of the different central nervous system divisions and its limits. Thus, in the fourth week of embryonic development three bulges or vesicles can be differentiated:

• The prosentephalon in the most previous part. During the fifth week, the prosentephalon will give rise to two new vesicles called Telencéfalo and DIENCEPHALO.
• The midbrain (middle part).
• The rhomboenphal (rhombus form) that continues with the neural tube that will finally lead to the spinal cord. During the fifth week, the rhomboencephal will give rise to metencephalon and honey.

Cell differentiation: fourth and fifth weeks

In parallel, a dorso-ventral pattern is established in a large part of the neural tube, which differentiates and separates two types of cells:

• The cells that will perform functions Sensory (dorsal region).
• The cells that will intervene in the Motor Coordination (ventral region).

Also, during weeks 4 and 5, the spinal ganglia begin to form in the flow zone of the neural tube.

Keep structures from: Sixth Week

From 6ª Week will originate, from the non -homogeneous differential growth of the aforementioned structures, other structures of the central nervous system:

• The telencéphalo will be formed brain hemispheres.
• Of the diencephalon, they will originate The thalamus, the hypothalamus, the subtálamo and the epitálamo.
• Of the metencephalon, The bridge and cerebellum.
• Of mylencephalon, The spinal bulb.

Ganglia and vesicles: Sixth Week

Towards 6ª development week will occur the union between peripheral nodes, formed of the migration of the cells of the neural crest, and the spinal cord, beginning to acquire its definitive organization.

Throughout all these processes, the neural tube hollow is expanding in the central nervous system originating the vesicles headache and maintains a smaller diameter in the middle and flow zone giving rise to the spinal cord channel.

Development of the fetus central nervous system

From the Ninth week, The cerebral circumvolutions.

But the formation of the nervous system does not end during the prenatal stage, since, after birth, there are a series of crucial events for the development of the nervous system.

Baby and Child Nervous System Development

The development processes nervous system of the baby and the child are:

• During the first four years after birth, the number of C progressively increasessynaptic ontacts in the brain In response to neuronal activity.
• From that period, and to puberty, there is a great synaptic reorganization (New synapses are established and those that are wrong or those not used are modified or eliminated). In these periods, the experiences and sensory stimuli that each individual has will determine the destiny and configuration that their synaptic contacts will have later.
• When the axons have finished their growth period, they have issued their collateral and have consolidated their connections begins the process of Myelinization (Formation of myelin pods around axons). The process begins in the prenatal period and ends in adulthood (Not before the age of 30, being able to reach 50).

Honeyinization is a fundamental process of the development of the SN because myelin increases the conduction speed of neural signals by axon. It has been shown that the amount of myelin varies between individuals Based on experience and of the changing environment in which they develop. Therefore, certain skills, such as learning a language at the level of a native, can be acquired during the myelinization phase of the neuronal circuits involved. Once the process is over, these processes are difficult since myelin prevents axons New connections. However, an adult's nervous system continues to maintain change capacity and some neural plasticity is preserved.

This article is merely informative, in psychology-online we have no power to make a diagnosis or recommend a treatment. We invite you to go to a psychologist to treat your particular case.

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