Green Vegetables are an important part of a healthful diet. In addition to supplying vitamins and minerals, the process of digesting them is beneficial to the digestive system. But human digestive system can’t process everything. For instance, lettuce is practically not digested at all.
Plant cells are each surrounded by a hard covering of cellulose which is not digestible in the human alimentary tract. If lettuce is well chewed, a leaf will pass into the stomach with some of its cells crushed. There it will be ground a little bit more. The cellulose covering will have allowed the water and some substances contained in the cells to be released. In the intestine, the shredded leaf will will release a little more water, vitamins (C and K), minerals salts. The protein, which it contains, is not accepted by our body, and it has practically no fats or sugars.
The small intestine will laboriously try to get through this leaf befre releasing it into the large intestine, However, this difficult, through not very productive task is very difficult, though not very productive task is very useful. In its effrts to extract something from the ingestible food, the intestine contracts, leaves and twists spiritedly. These movements are good for the functioning of the spiritedly. These movements are good for the functioning of the intestine, in the sample way that gymnastics are good for keeping the muscles in shape. However if cellulose is eaten in too large quantities, it could inflame the cells lining the interior and could cause enteritis.Indigestible Foods List