The histology it is the branch of the anatomy focused on organism tissue analysis . This is the discipline that studies from the microscopic level of tissues to their functions.
The Italian Marcello Malpighi (1628-1694) is designated as the founder of histology. This biologist and anatomist was the one who detected cells live for the first time. Thanks to microscopes increasingly powerful, histology was advancing throughout the seventeenth century and in the following years.
Starting from the microscopic structure of tissues, histology generates knowledge about the organization, interrelationships and functioning of the various individual components of the organism. That is why it is very important for the biology and for the medicine , among other sciences.
It is possible to distinguish between animal histology (which revolves around woven of animals) and the plant histology (plant tissues). In animal tissues, in turn, you can differentiate between nerve tissue, muscle tissue, epithelial tissue and connective tissue. Each one of them is detailed below:
* nervous tissue : this is the set of billions of neurons with their respective interconnections, which gives rise to a highly complex communication system. Each neuron has its receptors, which are located in their terminals and specialize in the perception of different kinds of stimuli, such as chemical, mechanical or thermal, among others, and in the translation of them to convert them into nerve impulses that later they can be processed;
* muscle tissue : it is made up of a series of contractile cells known as myocytes. These specialize in the generation of movement through the interaction of proteins also called contractile, which are myosin and actin. This type of tissue, of interest for animal histology, uses the chemical energy called ATP or adenosine triphosphate. In our body, it represents between 40 and 45 percent of our total mass;
* epithelial tissue : also known as epithelium. It is one or more layers of cells that serve to cover all free areas of the body. They also fulfill the function of covering the interior of the cavities, ducts and hollow organs, in addition to forming the glands and mucous membranes. On the other hand, they form one of the main concepts of histology, the parenchyma, which is defined as a tissue that has a specific function, for example, for the organ to which it belongs;
* conjunctive tissue : another name by which this concept is known is connective tissue. It is formed by organic tissues that arise from it origin and have the function of holding the various parts of the animal organism, of holding them together (what is called cohesion), as well as separating certain elements or even distributing certain vasculonervious structures. In this group you can distinguish the specialized conjunctive of the non-specialized.
The histological techniques These are the operations that allow preparing biological tissues for observation and study using a microscope. In this way, the professional can work with those structures that are not visible to the eyes of the human being .
As a first step, a tissue sample should be obtained, for which the procedure known as biopsy (tissue extraction). Then the tissue has to be placed in a fixing substance (such as formalin ) to keep its shape. Washing to remove excess fixative, placing the sample in paraffin, performing histological cuts and staining are other stages prior to the actual observation.