A 32-year-old chef accidentally slices into the tip of her thumb while hurriedly trimming ribeye steaks with a knife. The laceration extends through the skin into the subcutaneous pulp. Which of the following sequences is most likely to occur in the subsequent wound healing process?

Question

A 32-year-old chef accidentally slices into the tip of her thumb while hurriedly trimming ribeye steaks with a knife.  The laceration extends through the skin into the subcutaneous pulp.  Which of the following sequences is most likely to occur in the subsequent wound healing process?

Quizplus · Accepted Answer

11ec160b_39fd_36fb_9249_6f33cea83c11_MD0001_00 Acute wounds, such as the sharp laceration this patient sustained from a knife, transition through an organized healing process to restore continuity and tensile strength. This process involves activation and recruitment of different cell types during 4 sequential (but overlapping) phases: hemostasis, inflammation, proliferation, and maturation. Hemostasis, which occurs immediately after tissue injury, involves small vessel constriction, platelet aggregation, and clotting cascade activation that leads to platelet plugging, fibrin clot formation, and cessation of bleeding. For relatively minor injuries, hemostasis is often accomplished within minutes. The fibrin clot that is formed during this phase provides a scaffold for subsequent wound healing. Inflammation usually starts within hours of injury. During this phase, mast cells degranulate, releasing histamine and other chemical mediators that increase vascular permeability and promote cellular infiltration (eg, neutrophils, monocytes). Neutrophils digest bacteria, necrotic tissue, and foreign debris. Monocytes are transformed into macrophages, which secrete growth factors (eg, transforming growth factor-beta, vascular endothelial growth factor) that promote the next phase of healing. Proliferation, which begins during the inflammatory phase and continues for weeks afterward, leads to replacement of injured or missing tissue via the following: Epithelization: Basal keratinocyte proliferation and migration of new epithelial cells form a new superficial epithelial layer that acts as a barrier to bacteria. Fibroplasia: Fibroblasts proliferate and synthesize ground substance and collagen, forming a matrix into which capillaries can grow. Simultaneous contraction of myofibroblasts (ie, differentiated fibroblasts that produce contractile proteins) helps decrease the wound size. Angiogenesis: Proliferation and migration of endothelial cells from nearby blood vessels lead to ingrowth of new capillaries into the collagen matrix. Maturation, the final phase of wound healing, results in collagen remodeling and cross-linking, which are the primary mechanisms by which the tensile strength of the wound increases. Educational objective: Wounds typically heal according to an organized sequence of 4 phases: hemostasis (fibrin clot formation), inflammation (cellular infiltration), proliferation (reepithelization, fibroplasia, and angiogenesis), and maturation (collagen remodeling). __________ References: Factors affecting wound healing. (http://www.ncbi.nlm.nih.gov/pubmed/20139336)

A 32-Year-Old Chef Accidentally Slices into the Tip of Her