Our digestive system is responsible for breaking down the food we eat and turning it into nutrients that our body can use. While some of the steps in the process of digestion are obvious, others are less so. In this article, we will explore the steps in the process of digestion and explain what happens to our food as it makes its way through our body.
When we eat, the process of digestion begins in the mouth. Our teeth break down the food into smaller pieces, while our saliva starts to break down the carbohydrates in the food. This process is called mechanical and chemical digestion. Once the food is chewed and mixed with saliva, it forms a ball, called a bolus.
When we swallow, the bolus moves down the esophagus, a long muscular tube that connects the mouth to the stomach. The esophagus uses a series of muscle contractions, called peristalsis, to push the bolus down to the stomach.
Once the bolus reaches the stomach, it is further broken down by stomach acid and enzymes. The stomach churns the food, mixing it with the acid and enzymes to form a thick liquid called chyme. The acidic environment in the stomach helps to kill any bacteria that may be present in the food.
The Small Intestine
From the stomach, the chyme moves into the small intestine. Here, the nutrients in the food are absorbed into the bloodstream. The small intestine is lined with tiny finger-like projections called villi, which increase the surface area of the intestine, allowing for maximum absorption of nutrients.
The Large Intestine
After the small intestine has absorbed all the nutrients it can, any remaining liquid is passed on to the large intestine. The large intestine absorbs any remaining water and electrolytes from the liquid, leaving behind a solid waste product called feces.
The feces are stored in the rectum until they are ready to be eliminated from the body. When the rectum is full, the muscles in the rectum and anus contract, pushing the feces out of the body through the anus.
Common Digestion Questions and Answers
- Q: What is the function of the digestive system?
- A: The digestive system breaks down the food we eat and turns it into nutrients that our body can use.
- Q: What is peristalsis?
- A: Peristalsis is a series of muscle contractions that move food down the esophagus and through the digestive system.
- Q: What are villi?
- A: Villi are tiny finger-like projections that line the small intestine and increase the surface area of the intestine, allowing for maximum absorption of nutrients.
- Q: What is feces?
- A: Feces is the solid waste product that is left behind after the nutrients and water have been absorbed from the food in the large intestine.
The process of digestion may seem mysterious, but it is actually a series of steps that work together to break down the food we eat and turn it into nutrients that our body can use. Understanding how our digestive system works can help us make better choices about what we eat, and can help us maintain better overall health.
- Buckler, M. (2006). Digestive System. In World Book Online Reference Center. Retrieved from http://www.worldbookonline.com/wb/Article?id=ar154960.
- King, C. (2013). Anatomy and Physiology. Boston, MA: Cengage Learning.
- Marieb, E. N., & Hoehn, K. (2010). Human Anatomy & Physiology. San Francisco, CA: Pearson Education, Inc.