Module 4 - Chapter 6 - Wound Healing Flashcards
What is the ultimate goal of the inflammatory process?
the ultimate goal of inflammation is healing and repair.
What conditions favor the most favorable outcome of inflammation, which is a return to normal structure and function?
The most favorable outcome occurs when the damage is minor, no complications arise, and the destroyed tissues are capable of regeneration. This often happens in tissues like the skin, intestines, and liver.
What is the term for the process of restoring normal structure and function in tissues?
The process of restoring normal structure and function in tissues is called “resolution.” It may take up to two years to complete.
What role does IL-10 play in the resolution of inflammation?
Local production of IL-10 is believed to play a critical role in the resolution of inflammation.
When may resolution not be possible in the context of inflammation?
Resolution may not be possible in cases of extensive damage, tissues that are incapable of regeneration, infections leading to abscess or granuloma formation, or the persistence of fibrin in the lesion.
What happens when resolution is not possible in inflammation?
When resolution is not possible, repair takes place. Repair involves replacing damaged tissue with scar tissue.
What is the primary component of scar tissue, and what function does it serve?
Collagen is the main component of scar tissue, and it fills in the lesion, restoring most of the tissue’s strength.
What limitation does scar tissue have compared to the original tissue it replaces?
Scar tissue, primarily composed of collagen, cannot carry out the same physiological functions as the original tissue. This can result in a loss of function in the affected area.
What are the three processes involved in wound healing?
Wound healing involves processes that (1) fill in, (2) seal, and (3) shrink the wound.
what is the primary difference between primary intention and secondary intention healing?
Primary intention healing occurs in clean incisions with minimal tissue loss and closely apposed wound edges, while secondary intention healing occurs in open wounds with significant tissue loss.
What is the primary mechanism of wound healing in clean incisions with minimal tissue loss?
In clean incisions with minimal tissue loss, wound healing primarily involves collagen synthesis.
What are the characteristics of primary intention healing?
Primary intention healing involves minimal sealing (epithelialization) and shrinkage (contraction) and is relatively fast.
In what type of wounds does secondary intention healing occur?
Secondary intention healing occurs in open wounds with significant tissue loss, such as stage IV pressure ulcers.
What are the key components of secondary intention healing, and how does it differ from primary intention healing?
Secondary intention healing involves a longer process of epithelialization, scar formation, and contraction, and it requires extensive tissue replacement, which is not the case in primary intention healing.
Which types of cells can fully regenerate as part of the wound healing process?
Epithelial, hepatic (liver), and bone marrow cells are capable of complete mitotic regeneration in a process known as compensatory hyperplasia.
What happens when fibrous connective tissues heal?
In fibrous connective tissues like joints and ligaments, normal healing replaces the original tissue with new tissue that may have a different structure and function.
What are the three phases of wound healing, and in what order do they occur?
Wound healing occurs in three phases: (1) inflammation, (2) proliferation and new tissue formation, and (3) remodeling and maturation.
What is the role of the inflammation phase in wound healing?
The inflammation phase is the initial stage, involving the body’s immune response and tissue cleaning.
What processes are involved in the proliferation and new tissue formation phase of wound healing?
In the proliferation and new tissue formation phase, new blood vessels and connective tissue are produced, and the wound begins to close.
What occurs during the remodeling and maturation phase of wound healing?
In the remodeling and maturation phase, the healed tissue is reshaped and strengthened over time.
What is Phase I in wound healing, and when does it begin?
Phase I is the inflammatory phase of wound healing, and it begins almost immediately after an injury.
What are the key events that occur during the inflammatory phase of wound healing?
During the inflammatory phase, key events include coagulation (hemostasis), the infiltration of cells like platelets, neutrophils, and macrophages, and the formation of a fibrin mesh as a scaffold for healing.
What role do platelets play in the inflammatory phase of wound healing?
Platelets contribute to clot formation and release growth factors that initiate the proliferation of undamaged cells.
What is the function of neutrophils during the inflammatory phase?
Neutrophils help clear the wound of debris and bacteria, contributing to the initial cleaning of the wound.
Why are macrophages essential to the wound healing process?
Macrophages are crucial because they clear debris, release wound healing mediators and growth factors, recruit fibroblasts (cells important for tissue repair), and promote the formation of a new blood supply (angiogenesis) as the wound healing process progresses.
when does Phase II of wound healing, known as the proliferative phase, typically begin?
Phase II, the proliferative phase of wound healing, usually starts around 3 to 4 days after the injury.
What is the main change that occurs during the proliferative phase concerning the clot in the wound?
The fibrin that initially sealed the wound is gradually replaced by either normal tissue or scar tissue during the proliferative phase.
What are the key events that characterize the proliferative phase of wound healing?
The proliferative phase involves macrophage invasion, recruitment and proliferation of fibroblasts, collagen synthesis, epithelialization, wound contraction, and cellular differentiation.
How do platelets and macrophages contribute to wound healing during the proliferative phase?
Platelets help with clot formation and release growth factors that stimulate cell growth. Macrophages play a central role in clearing debris, releasing healing mediators, recruiting fibroblasts, and promoting the formation of new blood vessels.
What are some of the biochemical mediators secreted by macrophages during wound healing?
Macrophages secrete substances like TGF-β, angiogenesis factors (e.g., VEGF, FGF-2), and matrix metalloproteinases (MMPs) to stimulate various aspects of healing.
What is granulation tissue, and why does it have a red, granular appearance?
Granulation tissue grows into the wound from healthy tissue and contains invasive cells, new lymphatic vessels, and new capillaries. It appears red and granular due to these new blood vessels.
What is epithelialization, and why is moisture important for it during skin wound healing?
Epithelialization is the process by which epithelial cells grow into the wound from surrounding tissue. Keeping the wound moist prevents the formation of a scab, facilitating faster epithelialization.
