What are the functions of glandular hydra cells? What about a person? Is there a difference in this tissue in different organisms? What are the functions of glandular cells, from what and how are they built? What organisms have this type of tissue? For modern biology, glandular cells are a very interesting topic that allows you to get a qualitative idea of the features of the life of the body. In addition, the study of tissues provides answers to some questions related to pathologies. More than once, scientists have studied the process of proliferation of glandular epithelial cells in an attempt to find ways to solve human he alth problems.
General information
The main functionality of glandular epithelium cells is secretory. Cells that form organic tissue are sometimes called secretory cells. The specialized medical name is glandulocytes. Glandular epithelial cells have the necessary functionality for the production, release of specialized compounds, secrets to the surface of tissues. Modern biology knows many organs, systems, tissues regulated through secrets:
- skin;
- mucous organs;
- lymphaticway;
- blood vessels.
Glandular epithelial cells are divided into two categories, and for classification they analyze the features of secretion. The first two points of the above list allow us to classify tissues as responsible for external secretion, the last two points speak of internal secretion.
Structure of glandular cells
As it was possible to reveal in the course of specialized biological studies using high-power equipment, glandulocytes in their bulk have specialized secretory inclusions. They are normally located in the cytoplasm. In addition, each cell is equipped with the so-called Golgi apparatus and a rich, complex structured endoplasmic reticulum. Granules responsible for secretory function, organelles in glandular cells are located at opposite poles.
Where and how?
In their bulk, glandular cells are located in the structure of the basement membrane. In form, they differ significantly from each other, much is determined by the secretory phase. The cytoplasm of glandular cells capable of producing protein-based compounds is distinguished by an exceptionally complex endoplasmic structure of the granular type. It is the compounds produced by such a structure that play the role of enzymes for the digestive process. However, the result of the activity of glandular cells is not exhausted by this: other types located in other tissues produce other enzymes, compounds that activate and stimulate the work of organs,catalyzing biochemical processes in the body.
There are also structures that belong to the number of agranular ones. They are able to produce non-protein compounds - steroid, lipid complexes. Glandular cells, which are entrusted with such functionality, are also united in an endoplasmic structured network.
What to look out for?
Scientists have found that areas of increased activity of squamous glandular epithelium cells are distinguished by the accumulation of mitochondria. They seem to shrink to those points where biochemical processes allow the generation of secretory secretions.
During research, scientists paid attention to the structure of glandular cells of the pancreas, mucous membranes covering organs, as well as elements responsible for the supply of special compounds to the blood and lymph. It was found that the cell cytoplasm does not always contain the same number of granules. The value is determined by what phase the cell is currently going through.
Cytolemma
The specificity of the structure of this element is significantly different for the lateral, apical, basal cell surfaces. So, if we consider the lateral ones, here you can see contacts that close the cell quite tightly, as well as desmosomes. The contacts provide an environment for the apical cell structures. This helps separate the glandular lumen and the gaps between the cells.
But the cellular structures classified as basal are built a little differently. Here the cytolemma forms relativelyfew folds that can penetrate deep into the cytoplasm. Folds function most actively in glandular cells capable of producing compounds saturated with s alts. This is typical, in particular, for the glands responsible for salivation: ductal cells generate just such substances. Examining the apical surfaces, one can notice that they are covered with microscopic formations, most of all resembling a pile in their structure.
Cyclicity of life
Modern biology, having studied the peculiarities of the production of compounds necessary for the functioning of the body by glandular cells, has come to the conclusion that the most characteristic feature of such elements is the secretory cycle. Sequential steps:
- receipt of original building components;
- generation, accumulation of organic matter;
- removal of the produced compound (gets the organ in need).
Features of operation
In order for the glandular cells to produce the components required to maintain the work of the circulatory and lymphatic systems, the basal surface feeds these structures with specialized components necessary for work. These are inorganic compounds, low molecular weight organics, water. Glandular cells need amino-, fatty acids, polysaccharides.
Polycytosis in some cases allows cells to obtain large molecular compounds. Thus, organic matter predominantly enters, most often proteins. Admissionnecessary building materials allows living cells to generate the volumes of secretion required by physiology. The endoplasmic reticulum becomes a method of transporting substances to the Golgi apparatus, where the accumulation of isolated compounds is possible. Here they are rearranged under the influence of chemical reactions, acquiring a granular form. It is this product that is secreted into other systems and organs by glandular cells. The movement of cell production within this system is largely determined by the cytoskeleton. The correctness of the excretory function also depends on it. The cytoskeleton is commonly understood as a structured system that includes microscopic tubes, filaments.
No uniqueness
Many scientists pay attention that the indicated division into phases is rather conditional: the processes actually overlap. The production of the secret and the release of the components can occur almost without interruption, and the intensity of the release of the compounds created is sometimes activated, at other times it weakens. The extrusion process itself varies considerably. In some cases, granules enter the external environment, and at other times diffusion occurs, which does not require granulation of the components. There is a third case: the cytoplasm is simply transformed into a secretory mass.
Looking at this through examples, you can pay special attention to how the human pancreas functions. When food enters the digestive system, many secretory granules are produced at once in a fairly short period of time,literally thrown in by glandular cells. The next two hours the body spends on generating secretion and accumulating it in the cell mass. Granules do not form during this period, and the compounds necessary for external organs enter there in the process of diffusion.
Secretion types
Since different cells function with slightly different features, the secretion production system has specific differences. The scientific approach made it possible to structure the known information about this phenomenon, on the basis of which three types of secretion were identified:
- apocrine;
- holocrine;
- merocrine.
The latter is often called eccrine in specialized literature.
And if in more detail?
Eccrine type of secretion production involves the preservation of the structural features of glandular cells during the working process. This category includes, in particular, the cells that form the glands that provide salivation.
Apocrine type involves partial destruction in the process of functioning of a certain percentage of glandular cells. According to this logic, the secret is produced in the mammary glands. At the same time, the internal organs receive both the secretory product and the apical cytoplasmic component. An alternative option is to isolate microscopic villi (their tops) from cells.
The holocrine type is such a specific sequence of biochemical reactions during the secretion of glandular cells, when the cytoplasm becomes the location for the accumulation of the produced compound. The process is accompaniedcomplete destruction of the cell. Such mechanics is typical, for example, for the sebaceous glands located on human (and not only) skin.
What happens next?
Regenerative processes allow the cells of the secretion production system to recover. In some cases, they proceed directly inside the structures, in another case, cellular regeneration is necessary. The latter is expressed in the differentiation of the cellular structure of the cambium, the division of its tissues. This variant is typical for the holocrine mechanics of component secretion, but for the other two, an intracellular recovery mechanism is sufficient.
Control every step
The work of glandular cells is clearly controlled by the human nervous system. Additionally, there are humoral methods for monitoring performance. HC affects by releasing calcium at the cellular level, an alternative way is to increase the concentration of cyclic adenosine monophosphate. The process is accompanied by an increase in the activity of the enzyme systems of glandular cells. At the same time, metabolic processes are induced, microscopic filaments actively contract, and tubules (also of a microscopic scale) are assembled. All these stages are important components of the process of intracellular movement and subsequent excretion of the produced secretion into the organs that need it.
Glands
From the epithelial tissue, glands are created, that is, such organs, the composition of which is cells capable of producing the secret. They can produce a variety ofcomponents for regulating biochemical processes in the body. Secrets produced by the glands stimulate and control work:
- digestive system;
- organs responsible for growth;
- systems that provide interaction with the environment.
Certain glands in the human body are full-fledged organs that function independently. These include:
- pancreas;
- thyroid.
Others represent only an element of some complex organ. For example, special gastric glands are located in the stomach.
Features of classification
It is customary to talk about the glands:
- endocrine;
- exocrine.
Through the first mechanisms of internal secretion are realized, through the second - external.
Alternative division into groups involves assignment to one of two categories:
- unicellular;
- multicellular.
Science: exploring more than just humans
Speaking of these types of tissue, it is necessary to mention the structural features of the hydra glandular cell. It is known that this freshwater organism has about five thousand cells that ensure its performance and are capable of producing a secret. They are called ectoderm and are (mostly) on the tentacles, they also cover the sole of the body. The glands produce a rather adhesive substance, which allows the hydra to attach to the substrate. Tentacle-produced components providepossibility of movement. The endoderm is formed by glandular cells near the mouth. Thanks to the secretion of these tissues, the hydra is able to digest food.
