The Tufts University Health and Nutrition Letter for March 2022 has a great article titled “Your Amazing Digestive System.” It explains in great detail what happens to food from the time you look at it until it leaves the body. We take for granted what happens when we eat food, but the amazing digestive system is so complex that it is another extraordinary evidence of God’s wisdom and design. Consider the parts of the system as spelled out by the Tuft publication:
THE GASTROINTESTINAL TRACT: This tube runs from the mouth to the anus with a lining separating the food we eat from the inside of our body. Muscles and nerves control the speed of movement of the food, and nutrients are absorbed through the tube wall, which controls what nutrients are absorbed and how fast.
THE MOUTH: The smell and sight of food stimulate the secretion of saliva (which is why our mouths water), moistening and lubricating the food so we can swallow it. The saliva has an enzyme called salivary amylase, which begins to break down starches as the teeth grind the food into more digestible pieces.
THE ESOPHAGUS: This tube is about a foot long and connects the throat to the stomach. It has muscles to push the food along and a valve that opens to let the food enter the stomach.
THE STOMACH: When food enters the stomach, gastric acid and digestive enzymes break down proteins and kill unwanted organisms. Stomach muscles contract and relax, reducing the food to a diluted paste.
THE SMALL INTESTINE: Most nutrients are absorbed here, including proteins, carbohydrates, fats, and micronutrients. This tube is about 20 feet long and an inch in diameter. The small intestine uses enzymes from the pancreas and bile from the gallbladder to break down the food. There are three sections to the small intestine, the duodenum, the jejunum, and the ileum, each absorbing different nutrients.
THE LARGE INTESTINE: Also called the colon, this muscular tube is three times wider than the small intestine but only about five feet long. The colon absorbs beneficial nutrients not previously absorbed. Anything the body can’t use is passed on to the rectum. The large intestine also absorbs water and has a complex organization of bacteria called “gut-microbiota.” Those microbes use fiber to produce beneficial compounds and produce many hormones required for our immune system.
Our amazing digestive system design defies any chance explanation. Each precisely designed part is an essential contributor to our ability to eat and digest food. It is no wonder that so many diseases can negatively affect the digestive system. It is hard to read all we know about this system and not be reminded of Psalms 139:14, “I will praise you, God, for I am fearfully and wonderfully made: marvelous are your works and that my soul knows very well.”
— John N. Clayton © 2022
Reference: Tufts Health and Nutrition Letter