What are the functions of glandular hydra cells? And the man? Is there a difference in this tissue in different organisms? What are the functions of glandular cells, what are they made of and how? Which organisms have this type of tissue? For modern biology, glandular cells are a very interesting topic, which makes it possible to form a qualitative idea of the features of the vital activity of the body. In addition, tissue research provides answers to some questions related to pathologies. More than once, scientists have investigated the proliferation of glandular epithelial cells in an attempt to find ways to solve human health problems.
general information
The main functionality of glandular epithelial cells is secretory. The cells that form organic tissue are sometimes called secretory cells. The specialized medical name is glandulocytes. Glandular epithelial cells have the necessary functionality to produce, release specialized compounds, secrets to the surface of tissues. Modern biology knows many organs, systems, tissues, regulated through secrets:
- skin integument;
- mucous membranes of organs;
- lymphatic pathways;
- blood vessels.
The cells of the glandular epithelium are divided into two categories, and for classification they analyze the features of secretion secretion. The first two points of the list above allow us to rank the tissue as responsible for external secretion, the last two points speak of internal secretion.
The structure of glandular cells
As it was possible to identify in the course of specialized biological studies using high power equipment, glandulocytes in their bulk have specialized secretory inclusions. They are located normally in the cytoplasm. In addition, each cell is equipped with a 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 its bulk, glandular cells are located in the structure of the basement membrane. In shape, they differ significantly from each other, much is determined by the secretory phase. The cytoplasm of glandular cells capable of producing compounds based on protein is characterized by an extremely 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 limited to this: other types located in other tissues produce other enzymes, compounds that activate, stimulate the work of organs that catalyze biochemical processes in the body.
There are also such structures that belong to the number of agranular. They are able to produce non-protein compounds - steroid, lipid complexes. The glandular cells that are responsible for this functionality are also integrated into an endoplasmic structured network.
What to look for?
Scientists were able to identify that places of increased activity of squamous cells are characterized by the accumulation of mitochondria. They seem to be drawn to those points where biochemical processes make it possible to generate secretory secretions.
In the research, scientists drew attention to the structure of the glandular cells of the pancreas, mucous membranes covering the organs, as well as the elements responsible for the supply of special compounds to the blood and lymph. It was found that 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 specific structure of this element is significantly different for lateral, apical, basal cell surfaces. So, if we consider the lateral, here you can see the contacts, rather tightly covering the cell, as well as desmosomes. Due to the contacts, the environment of the apical cell structures is ensured. This helps to separate the glandular lumen and the gaps between the cells.
But classified as basal cell structures are built a little differently. Here, the cytolemma forms relatively small folds that can penetrate deeper into the cytoplasm. The most active folds function in glandular cells capable of producing compounds saturated with salts. This is characteristic, in particular, of the glands responsible for salivation: duct cells generate just such substances. Examining the apical surfaces, you can see that they are covered with microscopic formations, most of which are reminiscent of pile in structure.
Life Cycle
Modern biology, having studied the features of the production by glandular cells of the compounds necessary for the functioning of the body, has come to the conclusion that the most characteristic feature of such elements is the secretory cycle. Successive steps:
- receipt of the original building components;
- generation, accumulation of organic substances;
- excretion of the produced compound (gets the organ in need).
Features of functioning
So that glandular cells can produce the components required to support the functioning of the circulatory, lymphatic system, the basal surface nourishes these structures with specialized components necessary for the work. These are inorganic compounds, low molecular weight organics, water. Glandular cells need amino, fatty acids, polysaccharides.
Polycytosis in some cases allows cells to get large molecular compounds. Thus, organics predominantly fall, most often proteins. The receipt of the necessary building materials allows living cells to generate the volumes of secretion required by physiology. The endoplasmic reticulum becomes a method of transporting the substance to the Golgi apparatus, where the accumulation of isolated compounds is possible. Here they are rebuilt under the influence of chemical reactions, acquiring a granular form. It is such a product that glandular cells secrete into other systems and organs. The movement of cell production within this system is largely determined by the cytoskeleton. The correctness of the excretory function also depends on it. Under the cytoskeleton, it is customary to understand such a structured system, which includes microscopic tubes, filaments.
There is no certainty
Many scientists draw attention to the fact that this division into phases is rather arbitrary: the processes are actually superimposed. The production of secretions and the release of components can occur almost without interruptions, and the release rate of the created compounds is sometimes activated, at other times it is weakened. The extrusion process itself varies significantly. In some cases, granules enter the external environment, and at other times, diffusion occurs that does not require granulation of the components. There is a third case: the cytoplasm simply transforms into a secretory mass.
Considering this with examples, special attention can be paid to how the human pancreas functions. When food enters the digestive system, a lot of secretory granules are literally thrown in by glandular cells in a fairly short time. The next two hours the body spends on the secretion generation and its accumulation in the cell mass. Granules are not formed during this period, and the compounds necessary for external organs enter there in the process of diffusion.
Types of secretion
Since different cells function with slightly different characteristics, the secretion production system has specific differences. The scientific approach allowed to structure the known information about this phenomenon, on the basis of which three types of secretion were distinguished:
- apocrine;
- holocrine;
- merocrine.
The latter is often called eccrine in specialized literature.
And if in more detail?
The eccrine type of secretion production preserves the structural features of glandular cells during the work process. In this category belong, in particular, cells that form glands that provide salivation.
The apocrine type involves partial destruction during the functioning of a certain percentage of glandular cells. By this logic, secretion is produced in the mammary glands. At the same time, internal organs receive both a secretory product and an apical cytoplasmic component. An alternative is the isolation of microscopic villi (their apices) from the cells.
The holocrine type is such a specific sequence of biochemical reactions during the secretion of glandular cells, when the cytoplasm becomes the location of the accumulation of the produced compound. The process is accompanied by absolute destruction of the cell. Such mechanics are characteristic, for example, of sebaceous glands located on human (and not only) skin integuments.
What happens next?
Regenerative processes allow the cells of the secretion production system to recover. In some cases, they occur directly inside the structures; in another embodiment, cell regeneration is necessary. The latter is expressed in the differentiation of the cell structure of the cambium, the division of its tissues. This option is characteristic of the holocrine mechanics of component secretion, but for the other two, an intracellular restoration mechanism is sufficient.
Every step control
The work of glandular cells is clearly controlled by the human nervous system. Additionally, there are humoral methods for monitoring health. NS 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 fermentation systems of glandular cells. At the same time, metabolic processes are induced, microscopic filaments are actively reduced, tubules (also of a microscopic scale) are collected. All these stages are important components of the process of intracellular movement and subsequent excretion of the produced secretion into organs that need it.
Glands
Glands are created from epithelial tissue, that is, such organs, the composition of which is capable of producing secret cells. They can produce a variety of components to regulate biochemical processes in the body. Secrets produced by the glands stimulate and control the work:
- digestive system;
- responsible for organ growth;
- systems providing interaction with the environment.
Certain glands in the human body are complete organs that function independently. These include:
Others represent only an element of some complex organ. For example, special gastric glands are located in the stomach.
Classification Features
It is customary to talk about glands:
Through the former, mechanisms of internal secretion are realized, through the latter, external ones.
An alternative division into groups involves being assigned to one of two categories:
- unicellular;
- multicellular.
Science: exploring not only man
Speaking about these types of tissue, it is necessary to mention the structural features of the glandular cell of hydra. It is known that this freshwater organism has about five thousand cells providing it with the ability to work, capable of producing secretions. They are called ectoderm and are located (mainly) on the tentacles, they also cover the sole of the body. The glands produce a rather sticky substance, which allows the hydra to attach to the substrate. The tentacle-made components provide mobility. The endoderm is formed by glandular cells near the mouth. Thanks to the secretion of these tissues, the hydra is able to digest food.