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For this STEAM project, I chose to focus on the digestive system and the six steps and functions of the digestive system. I chose this because I found the digestive system most interesting this semester. The digestive system works together within the six steps, but there are times when something does not function as it should. I researched how Gastroesophageal reflux disease can affect the digestive system. In the drawings, normal and Gastroesophageal reflux disease digestion are seen along with symbols and color coding to show the steps.
The process of digestion and absorption can be described as, “the breakdown of food into particles small enough to cross the cellular barrier of the gastrointestinal (GI) system and be carried around the body in the circulation. This occurs by both mechanical and chemical processes that begin in the mouth and generally end in the small intestine” (McQuilken, 2021). The different steps of the digestive system include ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation (Betts et al., 2022).
Ingestion is when food enters the mouth and mixes with saliva and starting the breakdown of the food, which is represented by the orange coloring in the mouth. Propulsion is the movement of the food throughout the digestive tract, which is represented by the brown arrows throughout the tract. Mechanical digestion refers to the physical breakdown of the food, but causes no chemical changes, which is represented by the blue circles. Chemical digestion is the breakdown of the chemical molecules in the food by different enzymes, acids, and salts. This is represented by the purple x’s. Absorption is where we get the nutrients from the food through the small and large intestines, represented by the yellow coloring of the small and large intestines. Lastly, defecation is the undigested food being removed as feces, which is represented by the red coloring. These steps contribute to the functions of the digestive system. These functions are the breakdown of foods, releasing the nutrients, absorbing those nutrients into the body, and expelling the indigestible parts (Betts et al., 2022).
The digestive system’s many different steps work together, but as stated above, there are times it does not function properly. One of these is Gastroesophageal reflux disease, also known as GERD, which is the “presence of symptoms or complications that are directly related to the retrograde flow of gastric contents into the esophagus” (Tack & Pandolfino, 2018).
This can be seen in the drawing by the green stomach acid filling more of the stomach than is seen in normal digestion.
The stomach’s acid breaks down food before it goes into the small intestine. In normal digestion, the lower esophageal sphincter stops the stomach acid from going back up the esophagus. When someone has GERD, it usually means that the sphincter is not functioning. Along with stomach acid, other damage to the esophagus can be due to bile, digestive enzymes, and microbial pathogens. Overall, GERD does not necessarily change the steps or the functions in digestion, which is seen in the drawings where the steps look very similar. However, exposure to stomach acid affects other parts of the system, which means that exposure to the esophagus can cause inflammation, esophagitis, or Barrett’s metaplasia (Tack & Pandolfino, 2018).
References
Betts, J. G., Desaix, P., Johnson, E., Johnson, J. E., Korol, O., Kruse, D., Poe, B., Wise, J. A., Womble, M., & Young, K. A. (2022). Anatomy and physiology, 2E. OpenStax, Rice University.
McQuilken, S. A. (2021). Digestion and absorption. Anesthesia & Intensive Care Medicine, 22(5). https://doi.org/10.1016/j.mpaic.2020.12.009
Tack, J., & Pandolfino, J. E. (2018). Pathophysiology of Gastroesophageal Reflux Disease. Gastroenterology, 154(2), 277-288.
Laree Culbertson’s STEAM project breaks down the steps of digestion, explains the function of the digestive system, and described Gastroesophageal reflex disease (GERD). Culbertson first breaks down the six steps of digestion, ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation. The first step, ingestion, is when food in the mouth mixes with saliva, next, propulsion is the movement of the food throughout the digestive tract, mechanical digestion is o the physical breakdown of the food, chemical digestion is the breakdown of the chemical molecules in the food by enzymes, acids, and salts, absorption is when nutrients from food cross through the small and large intestines and are absorbed by the bloodstream, and, finally, defecation is the removal of food waste as feces. Culbertson’s project uses a drawing to visually represent the steps of digestion and compare it to digestion with GERD. Culbertson used different colors to show the different steps of digestion and where they occur in the digestive tract. She describes how GERD is the flow of gastric juices into the esophagus. Normally the lower esophageal sphincter prevents stomach acid from going back into the esophagus, but with GERD the sphincter is likely not functioning. Stomach acid, bile, digestive enzymes, and microbial pathogens can all cause damage to the esophagus. Stomach acid in the esophagus can cause inflammation, esophagitis, or Barrett’s metaplasia.
GERD does not change the steps or functions of digestion.