The Digestive System

The Digestive System: Function & Anatomy 

The digestive system is a network of organs that help digest and absorb nutrients from food. The digestive system includes the entire gastrointestinal tract and biliary system. The gastrointestinal tract is a series of hollow organs that all connect together. This system starts at the mouth and continues to the esophagus, stomach, pancreas, liver, gallbladder, small intestine, large intestine, and finally the anus. The biliary system is made up of the liver, gallbladder, pancreas, and bile ducts, while the gastrointestinal tract includes the mouth, esophagus, stomach, small intestine, large intestine, rectum and anus. While the size can vary depending on the person, an average adult's digestive tract is about 30 feet long. 

The digestive system turns food into the nutrients and energy our body needs to function and survive. These nutrients include carbohydrates, proteins, fats, vitamins, minerals, and water. The digestive system breaks this all down into absorbable nutrients, and the body uses these for important things like energy, growth, cell repair, and hormones. 

Each part of the digestive system plays an essential role in the process. Let's look at each part of the system and what role each part plays:

Mouth: The whole process starts in the mouth. When food is swallowed, the tongue pushes food into the throat; the epiglottis is a small flap of tissue that folds over the windpipe and prevents choking as the food passes into the esophagus. Digestion starts even before a bite is taken. The salivary glands activate when we see or smell food. When we begin chewing food, saliva mixes in with it to help start to break down food.

Esophagus: The esophagus is located in the throat near the trachea or windpipe. The esophagus receives food from the mouth. Peristalsis is a series of muscular contractions, and when it happens in the esophagus, it helps to move food to the stomach. At the bottom of the esophagus is a ring-like muscle called the lower esophageal sphincter; this has to relax to let food pass. It contracts and prevents the stomach’s contents from flowing back into the esophagus. 

Stomach: The stomach is a hollow organ that acts as a container to hold food as it is mixing with stomach enzymes. The enzymes help to break down food further into a more usable form. The cells in the lining of the stomach secrete stomach acid and enzymes. Once the stomach contents are processed enough, they are ready to move on to the next step in the process. 

Small Intestine: The small intestine is about 22 feet long and comprises three segments. The duodenum, jejunum, and the ileum. This muscular tube breaks down food using the pancreas and bile enzymes released from the liver. The first segment is the duodenum, which is responsible for continuously breaking down food. The jejunum and ilium are lower in the small intestine and help to absorb nutrients into the bloodstream. 

Pancreas: The pancreas is responsible for secreting digestive enzymes into the duodenum. These enzymes break down protein, fats, and carbohydrates. The pancreas is also responsible for making insulin and getting it to the bloodstream. Insulin is the hormone responsible for metabolizing sugar. 

Liver: The liver is the body's chemical factory. It takes raw materials absorbed by the intestine and makes chemicals or hormones that the body needs to function. The liver also filters out and detoxifies harmful chemicals. While the liver has many functions, its main job within the digestive system is to help process nutrients absorbed in the small intestine by secreting bile to help digest fat and some vitamins. Learn more about the liver here: insert link. 

Gallbladder: This bladder is a storage facility for bile from the liver when you are not eating; bile is concentrated here. When you eat, bile is released into the duodenum in the small intestine to help absorb and digest fats. 

The Large Intestine:Also known as the colon is responsible for processing waste. This 6-foot-long muscular tube connects the small intestine to the rectum, or anus. The colon comprises the cecum, the ascending or right colon, the transverse or across colon, the descending or left colon, and the sigmoid colon. Leftover waste from the digestive process is passed through the colon using peristalsis. This starts as a liquid state and forms into a more solid state. As the stool passes through the colon, water is removed. The stool then gets stored in the sigmoid colon, which is S-shaped. The stool is stored here until there is a “mass movement,” and it gets emptied into the rectum. It takes about 36 hours for stool to get through the colon. The stool is made up of food debris and bacteria. The bacteria here are “good” bacteria that work in symbiosis to perform valuable bodily functions such as synthesizing vitamins, processing waste, and protecting against “bad” or harmful bacteria. Once the descending colon is full of stool, also called feces, the content empties into the rectum for elimination. 

Rectum: The rectum is a straight chamber that is about 8 inches long which connects the colon to the anus. The rectum's responsibility is to receive stool from the colon, signal that there is stool to be emptied, and store stool until elimination can happen. Anything that comes to the rectum, such as stool or gas, triggers sensors and sends a message to the brain that it needs to be released. 

Anus: The last part of the digestive system is the anus. It is a canal about 2 inches long that consists of the pelvic floor muscles and two sphincters, one internal and one external. The lining of the upper anus detects contents and can let you know if the contents are liquid, gas, or solid. Sphincter muscles surround the anus and are responsible for the control of stool. The pelvic floor muscle creates an angle between the rectum and anus that helps stop the stool from coming out. The internal sphincter prevents involuntary evacuation when we are asleep or otherwise unaware of stool. When we get the urge to go, the external sphincter is responsible for holding things in until we are able to use the bathroom. Once we are in a place to do so, it relaxes and releases. 

Hormones & Other Systems

Both hormones and nerves work together to help control the digestive process. Signals flow within the digestive tract to and from the brain. Hormones play a significant role in this process, from telling the body when to make digestive juices to sending signals to the brain to let you know if you are hungry or full. The pancreas and liver both produce and work with hormones. Nerves connect the central nervous system to the digestive system and help to control some digestive functions. An excellent example is when you think of your favorite food and your mouth starts to salivate. This is to help prepare your mouth and digestive system for food. 

The enteric nervous system consists of nerves within the walls of the digestive tract. When food stretches the walls of the tracts, the nerves of the ENS release substances to help speed up or delay movements and digestive juices. The nerves send signals to control the actions of the gut muscles to contract or relax. 

Fun Body System Facts:

• The digestive system comprises 11 different organs: the mouth, salivary glands, throat, esophagus, stomach, gallbladder, liver, pancreas, small intestine, large intestine, and rectum. 
• When spread out, the small intestine is about 22 feet long and has a 2,700-square-foot surface area.
• The large intestine can sense when you are stressed and can become sensitive during times of stress. 
• Our mouths produce about 1 liter of saliva a day!
• The digestive system hosts more than 500 species of bacteria!

What is necessary for optimal digestive health? 

Water, hydration, and fiber are essential to keep this system running smoothly. The digestive system also needs particular vitamins to function correctly. 

B vitamins play a huge role in energy and metabolism. B1 helps to convert carbohydrates into energy and regulate appetite. B3 helps to break down carbohydrates, fats, and alcohol. B6 helps to process protein. Biotin helps to convert food into energy. B12 plays a role in the nervous system and the production of blood cells. These vitamins are found in proteins such as fish, poultry, meat, dairy products, leafy greens, and beans. 

Vitamin C is hugely important as it aids digestion by supporting healthy teeth and gums and helps the body absorb iron. Vitamin C can be found in citrus fruits, berries, tomatoes, peppers, and broccoli. 

Vitamin D helps the body absorb calcium and plays a vital role in the function of nerves, muscles, and immune system. Vitamin D is primarily found through sun exposure and in egg yolks, saltwater fish, and liver. 

Vitamin A helps vision, bone, and reproductive health. While it is not directly involved in digestion, it helps to support the health of the intestinal mucus lining. Vitamin A can be found in colorful fruits and vegetables, like sweet potatoes, carrots, kale, dark leafy greens, liver, and milk. 

Eating a nutrient-dense and hydrated diet helps to support digestive health. 

Nutrition Support: 

Whole Grains	Asparagus	Turmeric
Leafy Greens	Organic Oats	Zinc
Fermented Foods	Apples	Magnesium
Omega Rich Foods	Ginger	Iron
Probiotics	Fennel	Vitamins B, C, D
Kombucha	Aloe Vera	Chia Seeds

Digestive Health Recipe 

Aloe Vera is excellent for the digestive system because it helps keep you regular, boosts hydration, is cooling & calming, is rich in gut-supportive nutrients, and helps to balance gastric acid.

Aloe Vera Smoothie 

Ingredients

• 1 frozen banana
• 1/2 cup blueberries
• 1/4 cup aloe vera juice
• 1 cup coconut water
• Ice to blend

Directions

Add ingredients to a blender and blend until smooth. Taste test and adjust as needed. Serve and enjoy!

Lifestyle Support:  

• Stay hydrated
• Eat fiber
• Limit processed food & alcohol
• Eat and chew slowly
• Limit high-fat foods
• Eat on a consistent schedule
• Swap seed oils for avocado, coconut, or olive oil 
• Finish eating about two hours before bed
• Go for a walk after eating
• Take digestive enzymes
• Perform abdominal self-massages
• Practice deep breathing
• Meditate

Herbal Friends of the Digestive System: 

Ginger	Aloe Vera	Globe artichoke
Peppermint	Turmeric	Chamomile
Marshmallow	Fennel	Triphala
Slippery Elm	Gentian	Licorice Root
Cumin	Lemon Balm	Caraway
Cardamom	Dandelion	Oregano

Companion RidgeCrest Products: 

	Belly Be Happy®  Helps to support a healthy microbiome, balanced digestive health, and a happy belly. This product is best for those who enjoy a calm belly and do not need digestive enzyme support.
	LiverClean™  Helps to support normal liver function and healthy bile production to encourage gentle cleansing. The liver is unique in its ability to regenerate naturally. Give your liver nourishment to support this essential role in waste metabolization.
	SereniZen® (Formerly AnxietyFree) helps to support calm and well-being, emotional regulation, and a balanced stress response, helping the body feel calm and relaxed, mentally and physically.

 

Supporting Supplements:  

• Probiotics & Prebiotics
• L-Glutamine
• Berberine
• Lions Mane
• Digestive Enzymes
• Fiber
• DGL
• Psyllium
• Vitamin C
• Zinc

Related Blogs: 

• The Miraculous Microbiome
• The Gut-Brain Connection
• Benefits of Bitters
• Understanding & Picking Probiotics
• Top 5 Supplements
• Simple Digestive Solutions
• Health Benefits of Fermented Foods
• The Liver
• The Neuromuscular System
• Slippery Elm Digestive Recipe

 

 

About the Author

Shae Brackett   Our Customer Service Director and Social Media Manager has been with RidgeCrest since 2016. Shae is the mastermind behind our exceptional customer experience, ensuring every call, email, and customer experience is handled with love and care. She guides the customer care team, is our culture caretaker, helping to facilitate our employee experience, and our online creative oracle for our Facebook, Instagram, our blog, and meditations. She describes herself as creative, thoughtful, nature-loving, compassionate, and nurturing. Her favorite herbs are Ginger and Lavender, and she proudly recommends SereniZen® (formerly Anxiety Free), PhysiQOL™, SinusClear®, and Belly Be Happy®.  Learn more about our team here.