After food is broken down by digestion, the small, soluble nutrient molecules need to be taken into the bloodstream. This process is called absorption. The vast majority of this absorption happens in one specific part of the alimentary canal.

The small intestine is also where most of the water you consume is absorbed. However, any remaining water is absorbed further along in the large intestine, specifically in a region called the colon.

To absorb nutrients efficiently, the small intestine needs a massive surface area. To achieve this, its inner wall is lined with millions of tiny, finger-like projections called villi. Each villus is, in turn, covered in even smaller projections called microvilli.