AP Biology questions on the role of fibroblasts in wound repair

📚 Quick Study Guide

• 🧬 Fibroblasts are connective tissue cells that synthesize the extracellular matrix (ECM) and collagen, crucial for structural support.
• 🩹 During wound healing, fibroblasts migrate to the injury site, proliferate, and deposit new ECM components.
• 🧪 Growth factors like TGF-$\\beta$ (Transforming Growth Factor beta) stimulate fibroblast activity.
• 🔬 Myofibroblasts, a specialized type of fibroblast, exhibit contractile properties due to the presence of $\\alpha$-smooth muscle actin.
• 🌟 Myofibroblasts contribute to wound contraction, reducing the size of the wound area.
• 🚫 Dysregulation of fibroblast activity can lead to fibrosis or keloid formation.
• ⏱️ The process of wound repair involves stages: hemostasis, inflammation, proliferation (including fibroblast activity), and remodeling.

Practice Quiz

1. Which of the following is the primary role of fibroblasts in wound healing?
   1. A) Initiating the inflammatory response
   2. B) Synthesizing and depositing extracellular matrix
   3. C) Promoting angiogenesis
   4. D) Recruiting immune cells
2. Which growth factor is most associated with stimulating fibroblast proliferation and ECM production?
   1. A) Interleukin-1 (IL-1)
   2. B) Tumor Necrosis Factor-$\\alpha$ (TNF-$\\alpha$)
   3. C) Transforming Growth Factor-$\\beta$ (TGF-$\\beta$)
   4. D) Epidermal Growth Factor (EGF)
3. What is the main function of myofibroblasts in wound repair?
   1. A) Secreting antimicrobial peptides
   2. B) Promoting blood clot formation
   3. C) Contraction of the wound area
   4. D) Degrading damaged collagen
4. Which component of the extracellular matrix is primarily synthesized by fibroblasts?
   1. A) Elastin
   2. B) Collagen
   3. C) Hyaluronic acid
   4. D) Fibrin
5. What happens if fibroblast activity is dysregulated during wound healing?
   1. A) Accelerated blood clotting
   2. B) Decreased inflammation
   3. C) Formation of keloids or fibrosis
   4. D) Enhanced angiogenesis
6. In which phase of wound healing do fibroblasts play the most significant role?
   1. A) Hemostasis
   2. B) Inflammation
   3. C) Proliferation
   4. D) Remodeling
7. What cytoskeletal protein is highly expressed in myofibroblasts, enabling their contractile function?
   1. A) Vimentin
   2. B) Desmin
   3. C) $\\alpha$-smooth muscle actin
   4. D) Keratin