But just because you have a gym membership that you actually use doesnât mean you canât also have a few things at home for doing other types of workouts that you donât have time for at the gym, or for those days that you just canât make it out the front door.
The inside wall of the small intestine needs to be thin, with a really big surface area. This allows absorption to happen quickly and efficiently. If the small intestine had a thick wall and a small surface area, a lot of digested food might pass out of the body before it had a chance to be absorbed.
In the jejunum, fat, starch and proteins from the food material are broken down and absorbed by the intestinal lining. The lining is covered with millions of tiny villi, or finger-like projections, that greatly increase the surface area, allowing nutrients to be more efficiently absorbed into the bloodstream. In the ileum, which is the last part of the small intestine, water and nutrients (such as vitamin B12) are absorbed.