Nerve tissue (NT) is considered to be a structural element of the nervous system, originating from the brain and ending with nerve endings. If we consider the structure of the nervous tissue, it can be noted that it consists of nerve cells called neurons, associated auxiliary cells (non-neuroglia), as well as fibers and endings, it also includes blood vessels and connective tissue.
Developing from the ectoderm, NT forms the central nervous system. In it, cells gather in groups, thus, gray matter appears, while fibers gather in bundles, forming white matter.
Nerve tissue is characterized by conduction and irritability. So, the stimuli entering the cells are converted into impulses, which are transmitted to the corresponding organs, tissues or muscles. NT cells process and store information and can retrieve it from memory if necessary.
A neuron consists of a nucleus and its surrounding cytoplasm (pericarion), where mitochondria, ribosomes, the Golgi complex, Nissl substances, etc. are located. The processes that are represented by two species depart from it.
1. Dendrides - through them the impulse is transmitted to the cell body. They have a length of 0.2 microns.
2. Neuritis (axon) - along it the impulse is transmitted from the body of the cell. It ends with branching, forming connections with other neurons or organ tissues.
It should be noted that nerve cells can conduct impulses in exactly the same direction.
Nerve tissue has three types of nerve cells:
1. Afferent - generate pulses.
2. Effective - stimulate the tissues of organs to action. These include motoneurons and neurosecretory cells (participate in the regeneration process).
3. Associative - form connections between nerve cells.
Nerve fibers are processes of neurons surrounded by lemmocytes. They are bemyelin and myelin. Depending on their structure, they enter the structure of a particular department of the nervous system.
Nerve fibers end with special devices called nerve endings, with their help fibers connect to various tissue elements. There are two kinds of endings: affectors and synapses. The former conduct excitation from tissue to fiber, the latter, on the contrary, from fiber to tissue.
Also, the nervous tissue has neuroglia, that is, a group of cells that are between neurons. These cells perform functions such as protective, secretory, demarcation, support and trophic. They participate in the excitation of the fibers during their regeneration and degeneration.
Thus, considering the functions of the nervous tissue, the following can be distinguished: the production and conduct of electrical signals, the deposition and storage of certain information in memory, and the participation in the formation of behavior, thinking and emotions.
Thus, NT is a highly specialized type of tissue consisting of cells, fibers, endings and neuroglia. Cells have the property of recognizing irritations, being excited, generating certain impulses, and then transmitting them. Due to this, tissue is involved in the integration, correlation, adaptation of all organs, systems and tissues of the human body.
It should be noted when the nervous tissue has diseases, all the elements that are part of it suffer. In this case, pathological processes can occur, for example, inflammation, tumors or other malformations that can affect the human nervous system. Changes or loss of substances in NT are compensated by the growth of connective tissue or the development of cysts.
It should be noted that the nervous system as a whole consists of nervous tissue, due to which all processes in the human body are completed.