L3 Wound Healing and L4 Carcinogenesis - General Pathology PDF

3rd Stage / General Pathology Wound Healing, Carcinogen By: Anas esis Ramaid Wound Healing  Wound healing mostly means healing of the skin.  Begins immediately after an injury to the epidermal layer and might take years.  Has 3 overlapping phases which are inflammation, proliferati...

3rd Stage / General Pathology Wound Healing, Carcinogen By: Anas esis Ramaid Wound Healing  Wound healing mostly means healing of the skin.  Begins immediately after an injury to the epidermal layer and might take years.  Has 3 overlapping phases which are inflammation, proliferation, and remodelling. Any disruption leads to abnormal wound healing  Types of Wounds Closed Wound: The surface of the skin is intact, but the underlying tissues may be damaged. e.g. contusions, hematoma, or Stage 1 Pressure Ulcers. Open Wounds: the skin is split or cracked and the underlying tissues are exposed to the outside environment. Open Wound closed wound Types of Wound Healing Wound healing is classified as primary, secondary, and tertiary wound healing. Primary Healing Uncomplicated healing of a non-infected, well- approximated wound is defined as primary healing. e.g. Surgical wounds.  Secondary Healing If the wound healing course in this wound is disrupted by infection, dehiscence, hypoxia or immune dysfunction, the secondary healing stage begins. These types of wounds are more susceptible to infections and poor healing.  Tertiary healing it is delayed primary wound healing after 4–6 days. This occurs when the process of secondary intention is intentionally interrupted and the wound is mechanically closed. This usually occurs after granulation tissue has formed.  Chronic wounds may also cause breakages in the skin that need to heal. These include bedsores, other pressure injuries, and diabetes- related ulcers. Stages of wound healing Stages of wound healing All wounds go through different healing processes, ranging from the initial wound reaction to the later stages of creating new skin. Simple wounds, such as those without extensive tissue damage or infection, take about 4–6 weeks to heal. This does not include scar tissue, however, which takes longer to form and heal. Scar tissue will never return to 100% strength, but it will reach about 80% strength around 11–14 weeks after sustaining the initial wound. Step 1: Hemostasis Step 1: Hemostasis Step 1: Hemostasis Step 2: Inflammation During the inflammatory phase, the cleaning and healing of the area begin. Step 3: Proliferative phase Step 3: Proliferative phase The proliferative phase of wound healing occurs when the wound is stable. The body’s focus during this stage is to close the wound, create new tissue, and repair any damaged blood vessels in the area. Step 4: Remodeling phase  During the remodeling phase, the internal wound is mostly healed. The process switches to creating strong skin to replace the temporary tissue in the area. this process occurs around 2 or 3 weeks after the injury and can last for 1 year or longer. This is the active scar tissue phase of healing. What factors can delay wound healing, and how can they be managed?  ‫عرض فيديو بعنوان‬: How your body heals cuts scrapes and puncture wounds to the skin Carcinogenesis Carcinogenesis is the process of transforming normal cells into cancer cells. Key Steps: 1. DNA damage occurs. 2. Uncontrolled cell division. 3. Tumors develop invasive properties. Causes: Environmental factors (chemicals, radiation) & genetic predisposition. Tumor Progression: Invasion and Spread Invasion: Cancer cells invade neighboring tissues. Metastasis: Spread of cancer cells via bloodstream or lymphatic system. Stages: Local invasion, intravasation, extravasation, colonization.  Benign Tumors: - Define: Well-defined, encapsulated, slow- growing, non-invasive, rarely metastasize. Malignant Tumors (Cancer): - Define: Invasive, uncontrolled growth, potential for metastasis, often poorly defined. ‫‪:‬عرض فيديو بعنوان‬ ‫‪What is cancer‬‬