Life is hectic. To keep you running, your body absorbs oxygen from the air you breathe and nutrients from the food you eat. How does your body make sure it’s getting the most it can to get you through your day?
Your body increases the surface that’s exposed to the air and food. In the lungs, oxygen is absorbed from the air into the blood in tiny sacs that cluster around the ends of the lung’s airways. A person’s lung has about 480 million of these tiny sacs. With so many little sacs, the total surface that oxygen is absorbed through is about the size of a tennis court.
The digestive tract has a different trick to increase surface. The inside surface of the intestines is fuzzy like toothbrush bristles. The fuzziness increases the portion of the intestines that’s in contact with the food, maximizing the amount of nutrients that can be absorbed.
Try out this concept of maximizing exposed surface to maximize absorption by making a soup stock. Traditional methods to making stocks recommend simmering the vegetables and meat in water for six to eight hours to extract all the flavors. However, dicing the vegetables into smaller pieces can produce the same flavor intensity with only two hours of cooking. How? Finely dicing increases the vegetables’ surface that is exposed to the water. More flavor molecules can come out, shortening the total time needed to extract the flavors.
For more details on the cooking experiment, view this Advances in Physiology Education article.