Performed: Abdullaeva A. E. Checked: Pankiv I. G.

Histology (from the Greek histos -. Cloth, logos - teaching) - the science of the structure, development and functioning of tissues of animal organisms. Fabrics are cell system and non-cellular structures, united and specialized in the process of evolution to perform important functions in the body. For each of the main tissue systems inherent characteristic is their structural features, development and functioning. The subject of general histology, or the actual teachings of the tissues, are the general laws inherent in the tissue level of organization and features of specific tissues; subject of private histology - the laws of life and the interaction of various tissues at higher levels of the organization bodies. Private histology serves as the basis for the study of the microscopic structure of the morphological and functional units of authorities and authorities in general.

Domikroskopichesky period (IV century. BC. E. At 1665) is associated with the names of Aristotle, Galen, Avicenna, Vesalius, Fallopian. And it is characterized by attempts to release in the body of animals and human tissues inhomogeneous (hard, soft, liquid, and so on), and using techniques of anatomical dissection; Microscopic period (1665 to 1950). Starting time period associated with the name of the English physicist Robert Hooke that firstly improved microscope (state that the first microscopes were invented in the early XVII in.), And secondly, using it for the systematic investigation of various, including biological and published the results of these observations in 1665 in the book "micrograph", third, first coined the term "cell" ( "cellulitis"). In the future, it ensured continuous improvement of microscopes and the increasing use of them for the study of biological tissues and organs. Particular attention was paid to the study of the cell structure. Yang described Purkinje cells of animals in the presence "protoplasm" (cytoplasm) and the nucleus, and later confirmed the presence of R. Brown core and in most animal cells. The modern period of development of histology began in 1950, when the first electron microscope was used to study biological objects. However, for the present stage of development is characterized by the introduction of histology, not only electron microscopy, but also other methods:.. Cyto- and histochemistry, gistoradiografii, etc. It is usually used by a set of different methods to create not only a qualitative representation of the structures under study, but also to get thin quantitative characteristics. Especially widely different morphometric methods currently used, including automated processing of information received from the personal computer.

Tissues - historically (phylogenetically) developed system of cells and non-cellular structures with common structure, in some cases - a common origin, and specialized to perform specific functions.

The properties of any tissue bear the imprint of the entire previous history of its formation. Under the development of living systems are understood and its transformation in phylogeny and ontogeny. Fabrics as a system consisting of cells and their derivatives, arose historically with the emergence of multicellular organisms. Already in lower wildlife such as sponges and coelenterates, the cells have different functional specialization of different structure and accordingly, so may be combined in various tissues. However, these features have not strut tissue, cell transformation capability and accordingly some other tissues in sufficiently broad. As the historical development of the animal world make securing certain tissue properties and the possibility of their mutual transformations limited to, the amount of the tissue at a time gradually increased in accordance with the ever increasing specialization.

Causal aspects of tissue reveals theory parallelisms A.A.Zavarzina. He drew attention to the similarity of the structure of tissues that perform the same function in animals belonging to even very remote from each other evolutionary groups. However, it is known that when the only evolutionary branches diverged from a common ancestor such specialized tissues was not. Therefore, in the course of evolution in the different branches of the phylogenetic tree of their own, as it were, in parallel, there were organized the same tissue, perform similar functions. The reason for this is natural selection: if there were any organisms in which compliance with the structure and function of cells, tissues, organs violated, they were less viable. Zavarzin theory answers the question of why the development of tissue passed by and not in some other way, discloses aspects of the evolution of casual tissues.

There are several classifications of tissues. The most common is the so- called morpho- functional classification, in which there are four groups of tissues Epithelial tissue Tissues of the internal environment Muscle tissue Nervous tissue

Epithelial tissues are characterized by the union of cells in layers or bands. Through these tissue metabolism takes place between the organism and the environment. Epithelial tissue protection function operates, suction and excretion. Sources of formation of epithelial tissues are all three germ layers - ectoderm, mesoderm and endoderm.

Tissues internal environment (connective tissue, including skeletal, blood and lymph) are developing the so-called embryonic connective tissue - mesenchyme. Fabrics internal environment characterized by large amounts of extracellular matrix and contain a variety of cells. They specialize in the implementation of the food, plastic, protective and support functions.

Muscle tissues are specialized in the execution of movement functions. It develops mainly from the mesoderm (striated tissue) and mesenchymal (smooth muscle).