The connective tissue of the human body is differentiated from the germinal tissue - mesenchyme. In the process of this transformation, organs and tissues are formed that have a different structure and purpose. The connective tissue system includes smooth muscles, dense and loose connective and cartilage tissue, body fluids, and the vascular system.
The loose connective tissue forms capsules of organs and muscles. The main tissue structures are connective tissue cells, amorphous matter, and fibrous structures. The structure of cells and the functions they perform are very diverse. The main percentage is fibroblasts, which take part in the formation of protein, collagen precursor, mucopolysaccharides. There are other forms of fibroblasts involved in the formation of organs and tissues. These are osteoblasts, chondroblasts, etc. Connective tissue contains macrophages involved in inflammation and tissue repair reactions, and immune system reactions in the fight against viral and bacterial infections. Mast cells of connective tissue, which are formed in large quantities during inflammation, secrete mediators (histamine, etc.).
The main substance is the base uniting its cells and fibers. It consists of proteoglycans, polysaccharides and proteins. Proteoglycan chains contain hyaluronic acid, heparin, chondroitin sulfate. Hyaluronic acid determines the permeability of tissue membranes. Fibrous structures are composed of elastic and collagen fibers.
Functions Performed
Connective tissue has a supporting function, since it forms the basis of the skeleton, skin, and stroma of organs. The fabric has high strength and at the same time elasticity due to its fibrous structures.
The trophic function of tissue is explained by its entry into the blood, lymph, and vessels of the body. Proteoglycans are involved in water metabolism and metabolic processes in tissues.
The protective function of connective tissue is provided by the skin, membranes and capsules of internal organs. The reparative function consists in the ability of connective tissue to repair damage during injuries and inflammatory reactions.
Connective tissue diseases
The basis of connective tissue diseases is the development of the pathological process in the tissue itself or its derivatives. Since it is part of many organs and tissues, its diseases can be combined into groups. Diseases are combined according to the etiological and pathogenetic principle, according to the similarity of clinical manifestations.
The first group is rheumatism. The second group includes diffuse diseases (lupus, scleroderma, Sjogren's syndrome, systemic disease of connective tissue). The third group is systemic vasculitis. The fourth group is rheumatoid arthritis, juvenile arthritis. The following are: Ankylosing spondylitis, infectious arthritis and osteoarthritis.
Causes of connective tissue disease
Each individual pathology has its own etiological factors. But common causes of collagenoses are: streptococcal infection, mycobacterium tuberculosis, the causative agent of gonorrhea and syphilis, influenza viruses, rubella. A hereditary predisposition to the occurrence of systemic diseases is not ruled out. The leading factor in the occurrence of pathologies are malfunctions of the immune system. Tissue damage is caused by the deposition of immune complexes resulting from the response of the immune system to the influence of the etiological factor.
Clinical manifestations
Each specific disease has its own clinical manifestations, however, there are general characteristic signs. This is a progressive and prolonged course of the disease, a febrile period, joint damage, weight loss, allergic reactions, changes in protein fractions of the blood, damage to the skin, a positive result from the use of hormonal drugs.