In this article we will consider the concept of "histogenesis". This phenomenon will be defined in general terms, as a subject of study of biology. The definition of some terms related to the main object of this article, “histogenesis”, will be affected and we will familiarize ourselves with the course of this process at the embryonic level of development.
Introduction
Histogenesis is a common subset of the processes responsible for the formation and restoration of body tissues during the development of an individual called ontogenesis.
The regeneration and multiplication of cells of a certain type forming a tissue occurs with the participation of the germinal layer (the layer of the germinal body that forms during gastrulation). Each sheet allows the formation of a specific tissue. Muscle tissue is formed from the mesoderm, and nervous tissue is due to the onset of ectoderm, etc.
When answering the question of what is histogenesis, it is important to know about the frequent cases in which tissue can have several origins at the same time. This leads to the formation of different functions in them, despite their commonality. For example, the skin epithelium is bound to the onset of ectoderm cells, and the absorbing intestinal epithelium has endodermal “roots”. The main object of this article is a concept describing tissues and their development, which occurs from the moment of division of a fertilized cell, to the death of an adult. Different age-related processes can differ greatly, which leads to the multicomponentness of histogenesis. For example, the processes observed at the stage of the embryo are very different from those that occur already in the formed organism.
What is histology?
Histology is a science from which the main object of the article follows - histogenesis. It is a section of biological discipline and studies the processes of vital activity and the development of living tissues, and also determines their structure. Most often, these methods of cognition are carried out empirically (by experience). For example, tissues are cut using microtomes into thin layers. Histology differs from anatomy in that it studies the body specifically at the tissue level. There are several varieties of it: human histology, histopathology, quantitative and forensic histology. Introduction to general histology owes much to the concept of histogenesis.
Histogenesis at the embryonic level
Studying the processes of development of vertebrates, mankind saw clearly tracked general biological patterns in accordance with which the formation of tissues took place. The appearance of a number of embryonic leaves and the separation of the main primordia, which serve for the development of tissues and organs, are some of the basic concepts in histology. They are the "soil" from which the concept of "histogenesis" was formed. The essence of histogenesis is the formation of tissues from the layers of the germinal body.
A.A. Klishov (1984) believed that histogenesis is the complex coordination of proliferation "in time and space" of the body, cell growth, processes of their migration and interaction among themselves, the phenomenon of determination and differentiation, as well as the programmed process of death, etc. All the above terms are inherent in the germinal stage of development.
Cell processes
Histogenesis is a combination of many tissue-specific phenomena and processes of formation. Along with the cycle of renewal of cell populations, there is also a cyclic change of structures within the cell itself. This phenomenon is called physiological intracellular regeneration. An important role for histogenesis is played by the processes of cell movement. Most often they are observed at the stage of gastrulation.
Cells can change their volume due to the influence and presence of certain factors. Because of this, they can deviate from a healthy normal norm and turn into hypertrophic (above normal) or atrophied (below normal). The phenomenon of cell growth has a certain limitation, which determines the optimum relationship between the nucleus and the cytoplasm.