The given blank can be filled with transcellular transport absorption.
Transcellular transport comprises the conduction of solutes by a cell through a cell. One common illustration is the movement of glucose to the extracellular fluid from the intestinal lumen by the epithelial cells.
The epithelial cells use secondary and primary active transport, usually in combination with passive diffusion via ion channels, to generate transcellular transport across the epithelial tissues. This mode of conduction can either be secretion, transport from blood to the lumen, or absorption, that is, transport of lumen to blood.