Endocytosis The bulk transport of materials into cells across the plasma membrane by processes not involving diffusion o内吞作用：大量物质穿过细胞膜逐步地转运进细胞而并不涉及扩散或主动运输，被称为胞饮作用（细胞吸收）或胞噬作用（细胞吞食）。