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.
Skin (percutaneous, dermal) absorption is a term that describes the transport of chemicals from the outer surface of the skin both into the skin and into the systemic circulation. The surface area of an adult is about 20,900 cm3 and the surface area of a child of 6 years is about 9,000 cm3. 2  These figures and figures for other body parts or portions can be found in the EPA Exposures Handbook 1996 or estimated using other databases.