Bone tissue: features of structure and function
Bone tissue is a differentspecial mechanical properties of the supporting tissue, which consists of bone cells and a special intermediate substance. The composition of the intermediate substance includes collagen fibers (bone matrix) and various inorganic compounds. In addition, bone tissue has lacunar-canal system, consisting of a network of microscopic lacunae and tubules and provides intraosseous metabolism.
Bony cells are of three types: osteoclasts, osteoblasts and osteocytes. Osteoclasts are multi-nuclear large cells of monocytic origin, the size of which can reach 190 microns. These cells are involved in resorption (destruction) of bones and cartilage. In the process of reparative and physiological regeneration of bone tissue, osteoclasts perform its resorption. The activity of osteoclasts directly depends on the amount of parathyroid hormone, the increased synthesis of which entails the activation of osteoclast function, leading to bone destruction.
Osteoblasts are young, polygonalCubic bone cells lying in the surface layers of bone and surrounded by thin collagen microfibrils. The main function of osteoblasts is the synthesis of components of the intercellular substance - bone collagen, as well as the regulation of its mineralization.
Osteocytes are located in lacunae and are mature spindle-shaped multifaceted bone cells that regulate intraosseous metabolism.
There are two types of bone tissue: coarse-fiber and lamellar. In an adult, the coarse-fibrous bone tissue is located in the seams of the skull and the areas of attachment of bones to the tendons, contains an amorphous substance and disordered thick bundles of collagen fibers. The composition of lamellar bone tissue includes bone plates 4-15 microns in thickness from osteocytes, a basic substance and thin collagen fibers.
Bone tissue, like other organs of the humanorganism, is susceptible to various inflammations and diseases. Inflammers of inflammation can be brought into it with a blood flow, ie, hematogenous way, in the event that the patient has a purulent focus. Inflammations of bone tissue are called osteomyelitis, predisposing factors of which can be avitaminosis, trauma, overfatigue, cooling, etc. Depending on the intensity and speed of osteomyelitis, chronic, subacute and acute forms of the disease are distinguished.
The result of a prolonged inflammatory processBone tissue is a blockage of blood vessels and a violation of blood circulation (thrombosis). Thus, bones deprived of proper nutrition begin to dead and decay, as a result, necrosis (necrosis) and destruction of bone tissue. In addition, there is a rejection of necrotic bone and loss of communication with healthy bone tissue, so-called sequestrants are formed.
The main causes of osteomyelitis(inflammation of the bone tissue) are pyogenic microbes: streptococci, staphylococci and pneumococci, as well as intestinal, typhoid rods and other microbes. A variety of osteomyelitis is considered such inflammatory diseases as bone felon and tuberculosis of bones.
Treatment of osteomyelitis is to destroyinfection with antibiotics, which are selected individually depending on the type of bacteria. Reception of antibiotics lasts about two months. The first days of drugs are taken in the form of tablets, if after four days no improvement is observed, the introduction of drugs continues intravenously or directly into the osteomyelitis.