Answer
The intestinal epithelial cells shown have lots of surface area facing the lumen of the small intestine, surface are being critical for absorption, while they act as a barrier due to the impervious tight junctions which connect them, preventing the leakage of material between them from the lumen to other parts of the abdomen or vice versa.
Work Step by Step
Review the structure of these cells and their special parts/aspects: the microvilli and the tight junctions.