Lamellipodium

The lamellipodium (pl.: lamellipodia) (from Latinlamella, related to , "thin sheet", and the Greek radical pod-, "foot") is a cytoskeletalprotein actin projection on the leading edge of the cell. It contains a quasi-two-dimensional actin mesh (The overall shape is a flat sheet, but if you zoom into the mesh itself, the individual ropes occasionally hop over each other in 3D space); the whole structure propels the cell across a substrate. Within the lamellipodia are ribs of actin called microspikes, which, when they spread beyond the lamellipodium frontier, are called filopodia. The lamellipodium is born of actin nucleation in the plasma membrane of the cell and is the primary area of actin incorporation or microfilament formation of the cell.