Certified Wound Care Nurse (CWCN) Practice Exam

What type of cells release growth factors during the inflammation stage of wound healing?

1. Fibroblasts

2. Keratinocytes

3. Macrophages

4. Endothelial cells

The correct answer is: Fibroblasts

During the inflammation stage of wound healing, macrophages play a crucial role in releasing growth factors. These specialized immune cells are among the first responders to injury and are essential for orchestrating the healing process. Their primary function is to ingest and break down debris and pathogens, but they are also pivotal in secreting a variety of cytokines and growth factors that facilitate tissue repair. Macrophages produce and release several key growth factors such as vascular endothelial growth factor (VEGF), transforming growth factor-beta (TGF-β), and platelet-derived growth factor (PDGF). These factors stimulate the proliferation of fibroblasts, keratinocytes, and endothelial cells, contributing to the formation of granulation tissue, angiogenesis, and re-epithelialization. While fibroblasts do play a significant role in the proliferation phase by producing collagen and extracellular matrix components, it is primarily macrophages that are responsible for initiating this cascade of healing through the release of growth factors during the inflammatory response. This engagement is critical for transitioning the wound from the inflammatory stage to the proliferative stage of healing.