The Process of Wound Healing - Essay Example

?Wound Healing Discuss the process of wound healing for example a cut in the skin. Describe the roles of the capillaries and the formation of granulation tissue in the healing process. [Writer’s Name] [Institute’s Name] Discuss the process of wound healing for example a cut in the skin. Describe the roles of the capillaries and the formation of granulation tissue in the healing process. The phenomenon of wound healing is the natural curative response to a wound. The cuts on the skin go through a healing process inside our body. When the body experiences a cut, one’s body takes action against the wound in order to heal it. The capillaries play an important role in healing a wound. The four overlapping phases are used to explain the healing process. This is a systematic phenomenon. The four phases include homeostasis, inflammation, proliferation, and maturation. Homeostasis is a process which involves the platelets to form clots. Furthermore, the inflammatory cells deride injured tissue during the inflammatory phase. Epithelialization, fibroplasia, and angiogenesis occur during the proliferative phase (Romo III, n.d). The hemorrhage caused by disruption in the blood vessels is controlled by clot formation which contains fibrin mesh with aggregated platelets embedded in it. Fibrin is the end product of coagulation pathway which causes homeostasis to take place. It provides a scaffold for the migration of inflammatory and mesenchymal cells (Wound Healing, n.d). Platelet aggregation leads to release of cytokines. These cytokines influence wound healing either directly or indirectly. The processes of clot formation and platelet aggregation halt when stimuli for clot formation fritter away. Lysis of clot starts along with clot formation and is mediated by plasminogen activator. This activator converts plasminogen to plasmin (Wound Healing, n.d). The second phase is called inflammation. It starts when the tissue trauma stimulates the inflammatory response. “Immediately after injury intense local vasoconstriction occurs, mediated by circulating catecholeamines and prostaglandins released by injured cells. This is followed by vasodilatation and increased capillary permeability resulting in local edema. This is mediated by histamine, kinins, prostaglandins, leukotrienes, and endothelial cell products” (Wound Healing, n.d). The tissue does not observe presence of any leukocytes as yet. The wounded tissues contain neutrophils which hare the first leukocytes to appear in the wounded tissues. They phagocytose damaged tissue or bacteria. Neutrophils themselves are phagocytosed by macrophages (Wound Healing, n.d). There are a few symptoms observed when the wound is healing because of the physiological changes. The pH change is observed because of the breakdown of tissues and bacteria which also causes pain. This also results in swelling and decreased tissue oxygenation due to disruption of blood vessels (Wound Healing n.d). Furthermore, the white blood cells namely monocytes and lymphocytes start performing their functions in the healing process. Monocytes turn into macrophages when these white blood cells migrate from capillaries into extra vascular space. Macrocytes phagocytose bacteria and tissue debris and secrete enzymes called collagenase and elastase, which are responsible for breaking down damaged matrix (Wound Healing, n.d). Lymphocytes produce various factors like HB-EGF (Heparin binding epidermal growth factor) and basic fibroblast growth factor. Adding on to this, they are also involved in cellular and humoral immunity. Neutrophilis dominate for the initial 24-48 but 48-72 hours later they are outnumbered by macrophages which persist for a few days. However, after 5-7 days fibroblasts are the principal cell type (Wound Healing, n.d). The third phase called proliferation constitutes epithelialization, fibroplasias and angiogenesis. Epithelialization is the “process of covering a denuded surface with epithelium” (Medical Dictionary, n.d). Fibroplasia is another part of the proliferative phase. It signifies the formation of fibrous tissue (Medical Dictionary, n.d). The third process of the third phase is called angiogenesis. In physiological conditions, angiogenesis occurs in embryo development, during wound healing. This is in response to ovulation. However, pathological angiogenesis, or the abnormal rapid proliferation of blood vessels may result in over 20 diseases. These diseases comprise of cancer, psoriasis and age-related macular degeneration (Angio World, 2001). Meanwhile, granulation tissue forms and the wound begin to contract. During the maturation phase, collagen forms tight cross-links to collagen and protein molecules which increase the tensile strength of the scar (Romo III, n.d). There is primary and secondary healing. The primary healing involves uncomplicated healing of non-infected wounds. The four phases take place in order without any interruption, in this process. Healing by secondary intention involves generation of granulation tissue and epithelialization over it. The angiogenesis and epithelialization take longer in secondary healing because of which the wounds are more prone to infection and poor healing. If the healing by secondary intention is properly supervised, it may result in adequate cosmetic outcomes in some areas of the body (Romo III, n.d). As soon as the skin is cut, the body functions to limit blood loss by decreasing the amount of blood flowing to the wounded area. Moreover, the proteins in blood, such as fibrin, together with the blood platelets and plasma form a protective covering called a scab. Meanwhile, the skin regenerates underneath. However, the scab protects the wound from outside infection (Discovery Health Health Guides, n.d). The wound is steadily healed as new granular skin tissue begins to be generated. The new tissue starts at the edges of the wound and reaches the center until it has covered the entire of the lesion. Furthermore, once the wound underneath the skin has sealed itself with another skin layer, the scab sloughs off on its own (Discovery Health Health Guides, n.d). Furthermore, if the cut or scrape is shallow only the outer epidermis layer is affected and no scar is formed when the skin heals itself. However, if the cut went deeper, further into the dermis of the skin, then cicatrisation begins which is when the body forms fibrous scar tissue from the granular tissue (Discovery Health Health Guides , n.d). Hence, the deeper the wound is the greater the chance of it leaving a scar. In addition, a human’s body needs three to six weeks to link a deep cut by producing a protein called collagen at the site of the wound in order to repair it. After the wound is healed, it can take around two years for a scar form its permanent appearance (Discovery Health Health Guides, n.d). Finally, the last phase of the healing process is the remodeling phase which happens in around three weeks to two years. The new collagen forms increases the tensile strength of the wound. However, the scar tissue formed as a result is only 80 percent as strong as the original tissue (Fishman, n.d). Thence, the healing process is long, and involves different phases and stages. References III, T. R. (n.d.). Medscape: Medscape Access. Medscape: Medscape Access. Retrieved June 25, 2012, from http://emedicine.medscape.com/article/884594-overview#aw2aab6b7 Oswald, R. (n.d.). Discovery Health "How Skin Heals". Discovery Health "Health Guides". Retrieved June 25, 2012, from http://health.howstuffworks.com/skin-care/information/anatomy/skin4.htm Fishman, T. (n.d.). Phases of Wound Healing. Wound Care Information Network. Retrieved July 25, 2012, from www.medicaledu.com/phases.htm epithelialization - definition of epithelialization in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.. (n.d.). Medical Dictionary. Retrieved June 25, 2012, from http://medical-dictionary.thefreedictionary.com/epithelia fibroplasia - definition of fibroplasia in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.. (n.d.). Medical Dictionary. Retrieved June 25, 2012, from http://medical-dictionary.thefreedictionary.com/fibropla What is Angiogenesis ?. (n.d.). Angio World. Retrieved June 25, 2012, from http://www.angioworld.com/angiogenesis.htm Wound Healing. (n.d.). Wound Healing. Retrieved June 25, 2012, from http://www.cmki.org/LMHS/Chapters/5a-WoundHealing.htm Read More