Is a small intestine as big as a football field?

Answer 1

yes approximately

Answer 2

Yes, approximately, but not nearly as long. The idea is that the villi that make up the small intestine add massive amounts of surface area to it, such that if you flattened out the entire small intestine it would have roughly the surface area of a football field. The average adult small intestine is however only 15-20 feet in length while alive (shorter due to constant contractions inside the body) and closer to 30 feet after death.

Answer 3

Surface area is the amount of surface that is exposed in a space. For instance, a sheet of flat paper covers the same amount of area as a bigger piece of crumpled up paper, but the bigger piece of paper has more surface area. Folding and crumpling surfaces up makes it easy to fit more surface area into a smaller space.

Since villi are very tiny folds that stick out from the small intestines, more surface area is fit inside a smaller space. If you were to "flatten out" all the little villi of the small intestines it would cover a football field. Not so if the inside of the intestine were smooth.