Your Digestive System & How it Works

Sep 27, 2019 | General Medical

We survive and thrive because the food we eat is converted into energy as our body goes through the digestion process every day. Protein and meat, plant-based foods, and even carbohydrates and sugary snacks are all converted into energy that helps our bodies run. The digestive system includes quite a few vital organs, such as the esophagus, small intestine, colon, and anus. All of these organs and more are involved in the digestion process. Knowing more about how your body processes foods can help you make better eating choices that can keep you healthier. Read on to learn more about the digestive tract and its processes. 

What Is Digestion?

If you smell delicious food being cooked and notice you are salivating slightly, the process of digestion has already begun. When you begin to eat, your salivary glands will make much more saliva. The entire process takes place in the gastrointestinal tract and requires nine parts and functions in order for the process to work. The process begins when we start to salivate and ends the moment our bodies make waste products. Enzymes and hormones push the food through the gastrointestinal tract, and it takes roughly 30 to 40 hours for the whole process to complete. While not fully included as part of the digestive system, our bodies also use the liver, gallbladder, and pancreas to aid in the digestive process. 

The Mouth, Pharynx & Esophagus

The process of digestion begins in the mouth, but as previously mentioned, your salivary glands are gearing up long before food enters the mouth. Chewing (which is also known as mastication) breaks the food down into smaller pieces so that our digestive system can process the food more quickly. The tongue actually aids in digestion also and pushes saliva and food to the pharynx and then the esophagus. 

The pharynx is a more technical term for the throat, and at this point, the pharynx directs the food to the proper location. If food takes the incorrect path, instead of passing into the esophagus to be converted into energy, it will pass through the windpipe into the lungs. You may have heard people remark that a drink or food “went down the wrong tube” or “pipe.” This is what occurs when food takes the wrong path. Assuming the pharynx is working correctly, it helps move food to the esophagus.

The esophagus is a tube that connects the throat to the stomach. A process known as peristalsis occurs, which pushes the food through the esophagus and onward to the stomach. A valve known as the lower esophageal sphincter helps the food make that final push onward into the stomach. The sphincter also closes once this process is complete, which helps prevent heartburn or acid reflux after eating. 

The Stomach & Small Intestine

Once the food has entered the stomach, the stomach muscles work hard to mix the food, which turns it into a white liquid known as chyme. Stomach acid and enzymes further help in the breakdown of the food. The stomach muscles then push the chyme into the upper part of the duodenum, which signals the food’s arrival into the top part of the small intestine. This is where the pancreas and liver act to help further the breakdown of the food. 

The small intestine has three parts that food must pass through: the duodenum, jejunum, and ileum. The breakdown of the food occurs in the duodenum, while the jejunum and ileum are responsible for nutrient absorption. Nutrients pass through the wall of the small intestine and enter the bloodstream. Once the nutrients have been absorbed, the food then passes through the upper gastrointestinal tract, intending to move onto the colon, which is the lower part of the gastrointestinal tract. 

The Large Intestine (Colon)

The colon is considered the lower part of the gastrointestinal (GI) tract, and it serves to turn leftover food product into waste, which is excreted when we go to the bathroom. Like the small intestine, the colon has several parts that the food must pass through: ascending colon, transverse colon, descending colon, and sigmoid colon. The colon is roughly seven feet long, and the food will be converted to solid waste as it passes through. During this process, water is absorbed from what will be stool, and a hard stool is formed. The rectum stores the stool until we feel the need to use the bathroom. At this point, we realize we need to use the bathroom, and our anal sphincter will hold in the stool until we use the toilet. 

The Three Accessory Organs

It’s important to talk about the roles that the accessory organs play in the digestive process, such as the liver, gallbladder, and pancreas. The primary function of the pancreas is to make insulin for the body, but it plays a role in digestion as well. The pancreas also produces digestive enzymes, which aids in converting fats, proteins, and carbohydrates into energy to help fuel us. The liver is responsible for processing toxins and chemicals, keeping them away from our bodies. The liver also plays a role in fat digestion and elimination, and it creates bile to aid in the process. The bile is then stored in the gallbladder until the food has moved to the duodenum. At that point, the bile is released into the stomach.

Why Is Digestion Important?

Digestion is important because it converts food into nutrients and energy. The type of food we eat depends on what the digestive system breaks it down into. Food is either converted into:

  • Carbohydrates
  • Protein
  • Fats
  • Vitamins

Carbohydrates are created from foods such as starches, sugars, and fiber. Carbohydrates can either be simple or complex. You find many simple carbohydrates in staple foods, such as milk, fruits, and vegetables. Complex carbohydrates come from legumes, starches, bread, and cereals.

Protein is converted from such foods as eggs, meat, and many types of beans. Quinoa, which is a grain, even has a good source of protein. 

Fats are perhaps the best source that the body uses to make energy. You’ll find fats in oils, such as olive or vegetable, as well as butter, snacks, and shortening. 

Vitamins are sourced from many different types of foods. The most common types the body produces are vitamins B and C in addition to D, E, K, and A. 

If you need more information about the digestive system or would like to be seen by a physician, request an appointment with the Gastroenterology Consultants of Savannah.