What is connective tissue?

We explain what connective tissue is and how it is classified. In addition, what are the various functions of these tissues.

1. What is connective tissue?

It is known by the name of connective tissue or connective tissue to a diverse set of organic tissues of filling, support and connection of the organism , that is, that connects, separates and sustains the various organ systems that make up the body of living beings .

The connective tissue is generally of the fibrous type (collagen, elastin and reticulin fibers) , as well as a matrix of variable consistency composed of water , mineral salts, polypeptides and complex sugars. The cells of the connective tissue are usually quite separate from each other, and may or may not be equipped with specific functions, such as generating enzymes , defensive cells or other regulatory substances.

In general, we speak of connective tissue (in the singular) to refer to all connective tissues as a whole , whatever they may be , that share structural and functional similarities. Blood is a very particular case of connective tissue of liquid matrix, too, although it may not seem so.

2. Types of connective tissue

The connective tissue is classified according to its specialized functions, as follows:

Specialized connective tissue . Those connective tissues endowed with unique and particular functions. They are divided into:

• Loose connective tissue. It has a high content of cells and extracellular components of the matrix, much more abundant than the fibrous content. In turn, it can be of the following types:
  • Mucous connective tissue. In them a fundamental amorphous substance predominates, composed of hyaluronic acid and presenting a moderate cellular abundance. It is rare in adults, but abundant in the umbilical cord and in smaller quantity in the pulp of the teeth.
  • Reticular connective tissue. It has argyrophilic reticular fibers, composed of collagen, forming a network type network. Thus, for example, the stoma of the bone marrow, spleen, and parenchyma are composed.
  • Mesenchymal connective tissue. It is the tissue that makes up the embryonic mesenchyme, they are rich in mesenchymal cells from which the specific cells of each tissue come.
• Dense or fibrous connective tissue. In which the fibers predominate above the cells, and which in turn is classified as:
  • Regular dense connective tissue. The one that forms the tendons, ligaments and other fibers that support traction and therefore are arranged in the same direction, parallel to each other to achieve greater strength.
  • Dense irregular connective tissue. Collagen fibers randomly arranged and low fundamental substance, provides protection against the stretching of the organs, so it can be found in the capsule of each of them.

Non-specialized connective tissue . These are support and connection tissues that do not fulfill other specific functions, but instead fill the body. They are classified according to their nature in:

• Adipose tissue Composed mainly of lipids and / or fats.
• Cartilaginous tissue. Composed of cartilage, an elastic substance that acts as a cushion between the bones.
• Woven bone. Composed of mineralized tissues that we call bone.
• Lymphatic tissue The one that composes the lymphatic system, connecting the glands and serving as transport to the body’s defenses.
• Blood tissue. The blood and the cells that compose it.

3. Functions of connective tissue

The primary function of the connective tissue is that of the systemic integration of the organism, that is, to give support, cohesion, separation and to serve as a logistic means of communication to the organs and different systems that make up the body. For example, they support and separate the organs in the abdominal cavity, while allowing distribution between them of vascular and nervous structures .

On the other hand, specialized connective tissues also have hematopoietic, lymphoid or similar functions , contributing to the production of cells of different types or to the production of specific substances of internal regulation of the organism.