There are a variety of associations to choose from. The granulation tissue consists of new blood vessels, fibroblasts, inflammatory cells, endothelial cells, myofibroblasts and components of a new provisional extracellular matrix (ECM). The composition of temporary ECM differs from that of ECM in normal tissues, and its components come from fibroblasts. [29] These components include fibronectin, collagen, glycosaminoglycans, elastin, glycoproteins and proteoglycans. [38] Its main components are fibronectin and hyaluronan, which form a highly hydrated matrix and facilitate cell migration. [32] Later, this temporary matrix is replaced by an ECM closer to that found in uninjured tissue. Healing progresses faster in a clean, moist (but not humid) environment that is protected from heat loss, trauma and bacterial intrusion. The stages of healing are organized and follow four processes: hemostasis, inflammation, proliferation and maturation. Although the stages of healing are linear, wounds may recede or advance depending on the internal and external condition of the patient. The four stages of healing are: The contraction begins about a week after the wound, when the fibroblasts have differentiated into myofibroblasts. [55] For full-thickness wounds, contraction peaks 5 to 15 days after injury.
[38] The contraction can last several weeks[47] and continues even after complete reepithelialization of the wound. [4] A large wound can become 40-80% smaller after contraction. [32] [43] Wounds can contract at a rate of up to 0.75 mm per day, depending on the looseness of the tissue in the injured area. [38] The contraction is generally not symmetrical; On the contrary, most wounds have an “axis of contraction” that allows better organization and alignment of cells with collagen. [55] If the edges of the wound are not immediately approached again, there is a delay in primary wound healing. This type of healing may be desirable for contaminated wounds. On the fourth day, phagocytosis of contaminated tissues is in full swing, and the processes of epithelization, collagen deposition and maturation occur. Foreign matter is sealed by macrophages, which can turn into epithelioid cells surrounded by mononuclear leukocytes and form granulomas. Usually, the wound is surgically closed at this time, and if the “cleansing” of the wound is incomplete, chronic inflammation may occur, resulting in significant scarring. Wound healing is classified as primary healing and secondary healing. When a person suffers an injury as a result of trauma or injury, a complex and dynamic healing process is triggered.
The phenomenon of healing is represented by four different stages: hemostasis, inflammation, proliferation and maturation. Each subsequent phase is characterized by vital biochemical processes necessary for the well-being of an individual and the regeneration of cellular structures. If a wound is harmful enough, blood clotting and tissue regeneration result in a scar. Each scar is a tangible reminder of the cascade of events that promote wound healing and tissue repair. A fourth category is healing, which occurs with wounds that have only a partial skin thickness. [8] If the basement membrane is not broken, the epithelial cells are replaced within three days by division and upward migration of cells into the basal layer in the same way as is the case with uninjured skin. [38] However, if the basement membrane at the wound site is destroyed, reepithelization must occur from the edges of the wound and skin appendages such as hair follicles and sweat and sebaceous glands that enter the dermis and are lined with viable keratinocytes. [29] If the wound is very deep, the skin appendages can also be destroyed and migration can only occur from the edges of the wound. [47] The third phase of healing, the proliferative phase, focuses on filling and covering the wound.