Ans.  Villi are found to be very thin. In general, villi is not more than around 1.6 mm in length and could be as small as 0.5 millimetres long. This can be understood by the example, the diameter of the ink line formed by the tip of a fine ballpoint pen is 1.6 millimetres, while 0.5 millimetres is apparently even smaller.The villi overlap with depressions which are also termed as crypts, where the cells that form the villi and other parts of the intestinal lining are actually formed by your small intestine.These crypts are around one-third to one-fifth as long as your villi, when healthy.