Final answer:
The broad, flattened, veil-like protrusion that extends from a fibroblast cell and is located at the leading edge is called a lamellipodium. Lamellipodia are dynamic structures that are composed of actin filaments and play a crucial role in cell migration and wound healing.
Step-by-step explanation:
The broad, flattened, veil-like protrusion that extends from a fibroblast cell and is located at the leading edge is called a lamellipodium. Lamellipodia are dynamic structures that are composed of actin filaments and play a crucial role in cell migration and wound healing.
When a fibroblast cell moves forward, the lamellipodium extends in the direction of movement, allowing the cell to advance. Actin assembly and disassembly promote the extension of filopodia, which are thin, finger-like protrusions, and lamellipodia. These structures help the fibroblast cell to explore its environment and migrate effectively.
The formation and extension of lamellipodia are tightly regulated by various signaling pathways and proteins, such as Rho GTPases and the Arp2/3 complex. Additionally, lamellipodia facilitate the formation of focal adhesions, which are specialized sites of cell adhesion to the extracellular matrix.