Features of the structure of columnar tissue: the relationship between structure and functions

Features of the columnar leaf tissue structurecause the fulfillment of its most important functions. Thanks to this, the vital activity of the whole plant organism is realized. In this article we will examine the distinctive features of the anatomy and physiology of columnar tissue.

Features of the internal structure of the sheet

In the plant, the columnar tissue is located in the leaf. How is this organ arranged? It is covered with skin from the outside. This type of integumentary tissue consists of closely fitting living cells, among which are the stomata. Due to these structures, penetration of molecules of gaseous substances is provided: oxygen - in the plant, and carbon dioxide and water vapor - in the opposite direction.

Under the skin are the cells of the mainphotosynthetic tissue. They are large, loosely arranged, so they form the basis of the leaf. The conductive and supporting function is performed by veins - a combination of elements of the conducting and mechanical tissue. Together they form vascular fibrous bundles.

The basic tissue of the leaf

The main tissue consists of two types of cells: columnar and spongy. The latter have an oval shape, and in between them intercellular spaces are located. These structures take up to a quarter of the sheet. Elements of the basic fabric with intercellulars form the basis of the sheet, store various substances, participate in gas exchange. The features of the structure of the columnar tissue make it the main photosynthetic structure of the leaf.

Column fabric: location

Picture of a columnar cell tissue sheetillustrates the peculiarities of its location. It is located directly under the skin from the upper side of the leaves. Cells of this tissue, really resembling columns, can be placed in one or several rows. This location is explained by its main function - the realization of photosynthesis. It is optimal for absorbing oxygen and sunlight.

Features of the structure of columnar tissue

Columnar is a variety of basic tissueplants. Its cells have a cylindrical shape, are arranged vertically and are closely adjacent to each other. The number of layers of columnar tissue directly depends on the intensity of solar radiation. So, in the leaves of plants that grow in the light, there can be several. And in shade-tolerant species this tissue is poorly developed.

Picture of a columnar cell tissue sheetdemonstrates its main structure. This is a thin shell, nucleus, mitochondria, Golgi complex, EPS. The central position and the bulk of the cell is occupied by the vacuole. This cavity, filled with cell sap, is a kind of reservoir for the storage of water and the substances dissolved in it. Due to the presence of chloroplasts, the cells of columnar tissue are green, giving it to the entire leaf.

Photosynthetic may be different partsplants. For example, in cacti, whose leaves are reduced to thorns, this function is performed by a fleshy stem. Many unicellular organisms are capable of photosynthesis: chlamydomonas, euglena green, cyanobacteria.

Column fabric: functions to be performed

Columnal cells contain the largest number ofchloroplasts in comparison with other elements of the basic tissue. Therefore, their main function is the realization of photosynthesis. Its value is difficult to overestimate, therefore its scales are often called planetary.

This photochemical process occurs oninternal membrane of chloroplasts, provided that there is sunlight, carbon dioxide and water. The products of this reaction are glucose monosaccharide. Its plant uses as a source of energy, necessary for its growth and development. Connecting into chains, glucose forms a complex carbohydrate starch. Its granules are stored in reserve in the cytoplasm as inclusions.

The second reaction product of photosynthesis isoxygen. This gas is a necessary condition for aerobic respiration, which is the main sign of all life on the planet. The essence of this process is the oxidation of organic substances with the release of the energy of their chemical bonds. The peculiarities of the structure of the columnar tissue also ensure the orientation of the chloroplasts, which allows them to capture sunlight as efficiently as possible.

Thus, columnar tissue is a varietymain. Its cells have a cylindrical elongated shape and are arranged vertically under the upper skin of the leaf. The functions of columnar tissue are determined by the structural features: its cells contain the green plastids of chloroplasts and ensure the flow of photosynthesis. This process of planetary significance provides the main conditions of life. As a result, plants are provided with organic substances, due to which they feed, and all other organisms - with oxygen, necessary for breathing.