tissue

The entire human body is made up of water and a combination of chemical components. The body's cells, the so-called spark plugs, are important building blocks. A collection of differentiated cells represents that tissue The cells perform tasks similar to those of the tissue itself, in order to enable the processes in the body and to form the necessary building material for the organs. In general, most of the body's cells are grouped into tissue. B. the muscle and nerve tissue. Opposite are the germ cells. They do not form a fabric.

What is tissue?

Generally speaking, tissue is a functional unit that is made up of cells and enables higher levels of hierarchy, such as organs, to be built up. The entire organization of the cells in the tissue is particularly important for cell growth, since cells react differently when they work together than individual cells.

Anatomy & structure

There are several types of tissue throughout the organism, which can be divided into four main groups. The skin tissue, also called epithelial tissue, takes up the outer and inner surfaces. The supporting or connective tissue holds the organs, bones and body parts in place and connects them. Gaps are filled, including fatty tissue, bones or cartilage. New tissues for the blood and free cells are also formed here.

The muscle tissue is responsible for the active movement and cells are formed from the nerve tissue that keep the brain, spinal cord and nerves going. Lymph and blood can also be counted among the basic tissue types. Even the organs are composed of intermediate and functional tissue.

Different types of tissue usually work together in organ structure. The muscle is built up from connective and muscle tissue, the skin from connective and epithelial tissue.

Different types of tissue differ in their cell wall properties, content and shape. Plants adapt better to the environment the more tissue they have. Plants consist of two different types of tissue. If the embryonic cells are capable of dividing, this is referred to as a formation tissue, if the cells are not capable of dividing, this is referred to as permanent tissue. This in turn has a base tissue, consisting of parenchyma, collenchyma (firming tissue made up of living cells and expandable cell walls) and sclerenchyme (firming tissue made up of dead cells and thickened cell walls), a closing tissue, consisting of epidermis and periderm, and a conducting tissue, which in turn consists of xylem and Phloem is composed.

Function & tasks

The research and examination of the tissue is called histology. The exact mechanisms of tissue formation are largely analyzed and not fully understood. Histology was founded by the anatomist and physiologist Xavier Bichat at the end of the 18th century, who discovered different types of tissue in the human organism and was still able to describe twenty-one of them without the use of a microscope. He himself was only thirty years old and died of tuberculosis.

Even today, histology examines tissue samples. They are viewed under a light microscope as microscopic and colored tissue sections. This allows early diagnoses about z. B. provide benign and malignant tumors or metabolic diseases, which can then be treated in good time. In medicine in particular, every tissue removed must be examined. A finding is particularly important when it comes to the malignancy of a tissue change.

Diseases

Histopathology examines abnormal changes in the tissue. The emergence of this subject can be traced back to Johannes Müller, who in 1838 a. a. wrote about structural properties of cancer. The actual founder was the German doctor Rudolf Virchow.

Histopathology belongs to the field of pathology and deals with the microscopic, fine-tissue aspect of pathological physical changes. The task is to analyze tissue samples from the various organs with the aim of precise assessment and diagnosis. Here, too, colored tissue sections are used, which are examined specifically for changes by a pathologist. The representation under the microscope is improved by molecular biological and biochemical methods. The appropriate therapy, prognosis and response to medication can be derived from this.

Human tissue in particular is extremely susceptible to changes and causes various types of cancer, e.g. B. skin cancer. It is now possible to create artificial tissue.For example, a human muscle has already been grown through the use of muscle precursor cells. The cells were already beyond the stem cell stage, but could not yet be called muscle cells. Muscle fibers formed from them.

In medicine, researchers are trying to rebuild damaged organs. Biological tissue such as skin or cartilage serve the healing process and can also be artificially grown if there is too much tissue loss. This is done using what is known as TE - Tissue Engineering, an umbrella term for the production of artificial tissue by cultivating human cells, whereby whole organs or parts thereof are reconstructed from human cells. These help to regenerate or replace diseased tissue, to preserve, renew or simply improve the tissue function.

In TE, cells removed from the donor organism are multiplied in a laboratory. This can take place as a cell lawn through two- or three-dimensional cell frameworks, which are then transplanted back into the diseased tissue. This restores tissue function.

Growing the tissue is problematic because it has to be ensured that the cells retain their specific functionality. For example, vessels must be able to build up a tissue. That is i.a. succeeded by increasing the number of differentiated cells in blood vessels, skin and cartilage tissue. Research is also being done on replacement tissue, e.g. from another human or animal. The TE was successful with tissue from one type of cell, e.g. the tissue of the cartilage.