The wound healing process and the different stages of repair. (2023)

The human body is a complex machine made up of many organ systems that work together to keep you healthy. One of the best examples of the diverse and complex body systems involved in the wound healing process. The wound healing process, along with the wound care products your doctor prescribes, work together to repair, replace, and heal damaged tissue. However, the big question here is how do you do all of this to magically heal our bodies and keep us in good health? Read on to learn more about the wound healing process and the different stages of wound healing.

The wound healing process.

Wound healing is a complicated process performed by the skin system. During wound healing, it is actually the skin, the largest organ in the body, that goes through the process of repairing the damage caused by wounds. Therefore, it is important to first understand the structure of the skin in order to understand the wound healing process.^(1,2)

The skin is the largest and heaviest organ in the body and covers the entire external surface while providing the first line of defense against pathogens and harmful environmental factors such as ultraviolet (UV) rays from the sun. The skin is made up of three layers, the epidermis, the dermis and the hypodermis or subcutaneous layer. The structure of the skin consists of an intricate network that acts as the body's first physical barrier to protect it from pathogens, chemicals, ultraviolet radiation, mechanical injury, and also to regulate temperature. The skin also controls the amount of water released into the environment.^(3,4)

The wound healing process actually refers to the healing of the skin, as a wound forms when the epidermal (outermost) layer of the skin is broken or torn. Wound healing begins immediately after injury to the epidermal layer. It is a highly complex and dynamic process that involves many mechanisms, including organized cellular, molecular, and humoral mechanisms.⁽⁵⁾

Let us now consider the different stages of repair involved in wound healing.

Repair phases in wound healing

When you sustain an injury, your body immediately triggers a series of automatic events, sometimes called a healing cascade. All wounds must go through different healing processes, from the initial wound reaction to the advanced and final stage of new skin formation. Simple wounds, p. B. those without extensive tissue damage or infection may take four to six weeks to heal. However, this does not include the healing time for scar tissue, which takes longer to form and heal.⁽⁶⁾

It is important to realize that although scar tissue never returns to 100% of its original strength, it reaches at least 80% strength 12-15 weeks after the initial injury.⁽⁷⁾

After an injury, the healing cascade is generally divided into four overlapping stages or phases. These include hemostasis, inflammation, proliferation, and maturation.

Let's take a closer look at the four stages/stages of wound healing:

1. hemostasis phase

   The hemostasis phase begins as soon as the injury occurs and is the body's first reaction to the wound. The injury causes blood and other fluids to drain from the body, and in return, the body responds by doing everything it can to stop the flow of blood.

   The affected blood vessels immediately narrow to reduce blood flow. Some studies have shown that thrombocytes and platelets in the blood also begin to clump near the site of the open wound and form a fibrin network almost immediately.⁽⁸⁾The fibrin network is responsible for thickening the blood in the affected area to stop bleeding.^(9,10)

   As the blood thickens, it forms a clot to prevent harmful germs from entering the body through the injury site. This also restores the skin's ability to act as the first line of defense against dirt and pathogens to allow for the healing process. At the same time, the platelets release certain types of specialized chemicals that alert neighboring cells to begin the next phase and begin wound healing.

   (Video) Wound Healing: Mechanism, Types, Primary, Secondary & Tertiary intention of healing & Complications

2. inflammatory phase

   The inflammatory phase is dedicated to cleaning and healing the injured area. Once you get a wound, you will find that there is some inflammation in the area. This happens because immune cells immediately rush to the damaged tissue, and white blood cells known as neutrophils arrive on the scene to begin cleaning the wound. White blood cells also carry waste away from the site of injury and eventually out of the body. These neutrophils normally reach their peak population within 24 to 48 hours of injury and begin to decline by the third day.⁽¹¹⁾

   After these white blood cells are gone, specialized cells known as macrophages arrive at the site of injury to continue to clean up debris. At the same time, these cells also release certain growth factors and proteins that attract immune cells to the injured area to allow tissue repair.⁽¹²⁾

   This phase is also sometimes called the defense phase because it focuses on destroying any bacteria and removing debris. It can be said that in the second phase of wound healing, the wound bed is prepared for the growth of new tissue.

   The inflammatory phase lasts four to six days and is often associated with redness of the skin, warmth, pain, and swelling.

3. proliferative phase

   The proliferative phase occurs when the wound is relatively stable. The body's focus during this phase of wound healing is to close the wound, make new tissue, and also repair damaged blood vessels in the area. The proliferation phase occurs through four different processes. These include:⁽¹³⁾

   • epithelization:This is the process by which new skin tissue is produced in different layers of damaged skin.
   • Angiogenesis:This process involves the creation of new blood vessels in the affected area.
   • Collagen production:This process initiates the production of collagen to strengthen the wound tissue.
   • Contraction:This part of the proliferative phase involves reduction of the size and area of ​​the wound and, finally, closure of the wound.

   The proliferative phase also sees the union of blood vessels and connective tissue to form what is known as granulation tissue. This granulation tissue begins to form about four to five days after the wound heals.⁽¹⁴⁾

4. maturity stage

   In the last phase, the so-called maturation, the newly formed tissue slowly begins to gain strength and elasticity. Collagen fibers begin to reorganize as the tissue remodels to mature. There is also a general increase in tissue tensile strength, although this strength is limited to about 80% of pre-injury strength. The maturation phase varies greatly depending on the type of wound and usually lasts between 21 days and two years.⁽¹⁵⁾

Diploma

The wound healing process is complex and remarkable, but it can be susceptible to disruption due to a number of local and systemic factors, including infection, age, diet, body type, humidity, and even environmental factors. When you create the proper healing environment, your body works properly to heal the wound and replace damaged tissue.

References: