What Happens to Food after You Put it in Your Mouth?

What is happening when we feel hungry? Or when we feel thirsty? What we are feeling is hormones signaling our brains that we need food or we need water. Hormones—made by the endocrine system—play a large role in our digestion process. They help maintain homeostasis by stimulating appetite, thirst, as well as many, many other bodily functions.

Digestion is the process of food (and drink) being broken down and absorbed. The mouth begins the digestion by breaking down food mechanically and beginning chemical digestions. Protein is digested in the stomach. The small intestine finishes the chemical digestion and absorption of food. The large intestine absorbs excess water from the waste and finally passes it through the anus.

What happens to those meals when they enter our mouths? There are the main things that happen:

  1. Digestion. Digestion involves the breakdown of what we consume into nutrients. The first step is mechanical digestion—chewing. After we mechanically break down the food with our teeth, we begin chemical digestion. Chemical digestion breaks down what we eat and drink chemically. Chemical digestion is mostly accomplished by proteins called enzymes.
  2. Absorption. After we’ve broken down the nutrients we need, we absorb them into our body. This step is called absorption.
  3. Elimination. Lastly, we excrete solid and liquid waste.

Enzymes make reactions go faster—they are catalysts. They are found at every important step of digestion. Amylase is found in our saliva (in our mouths). It helps breaks down bread-like things (starches) into smaller sugar molecules.
Pepsin helps us digest protein in our stomachs. Pancreatic lipase breaks down fats. It is secreted by the pancreas.

The digestive system is essentially one long tube. It begins with the mouth and ends with the anus. On average, it is thirty feet long! In between the mouth and anus are many organs which play various roles; esophagus, stomach, small intestine, large intestine, and anus, to name a few.

Food is moved through the tube via muscle contractions. The muscle contractions start in the esophagus and end in the anus; moving in a wave called peristalsis. Peristalsis is the name of the movement of the muscle contractions moving the food through the tube.

Digestion begins in the mouth. In the mouth, the teeth digest food mechanically, and the saliva digests starches chemically. And so begins the journey. After the mouth, the food travels to the stomach through a narrow tube called the esophagus. The esophagus moves the ball of chewed and partially digested food via peristalsis into the stomach.
Once in the stomach, the food is further chemically digested. The protein is digested with the enzyme pepsin. Pepsin, along with other chemicals such as hydrochloric acid (HCl) chemically digest the food. Water, salts, and simple sugars are absorbed through the walls of the stomach. The rest of the nutrients are absorbed after exiting the stomach.

The small intestine is about 7ft long in adults and is composed of three parts. Even though it’s only seven feet long, if it were spread out it would cover a basketball court! The large intestine takes the liquid waste from the small intestine, absorbs the excess water, and excretes the solid was through the anus. The large intestine is home to trillions of helpful bacteria. Although we often think of bacteria as harmful, we want the bacteria in our small intestines. We have a symbiotic relationship with the bacteria in our small intestines—we help each other to live. Among other functions, the bacteria in our large intestines produce vitamins B12 and K, as well as break down poisons.

The liver is essential to digestion, and life. The liver detoxifies the blood, maintains the glucose balance, synthesizes proteins, and produces many chemicals needed for digestion. The liver is essential to life perhaps that is why it is called the liver.

Getting the right nutrients and getting fiber in your diet is extremely important. The nutrients keep your system running well, while fiber helps to move waste through your digestive system. If you do not get enough fiber you may become constipated; unable to pass waste.

Maintaining a healthy digestive system means a.) maintaining a healthy diet, and b.) taking care of any illnesses, allergies, or intolerances which arise.


2 Responses to “What Happens to Food after You Put it in Your Mouth?”
  1. lynn_mcaleece says:

    Please fixate typos in this section. There were a number of them again, which make the content more complicated than it needs to be.

  2. Rebekah Small says:

    Hi the measurements don’t add up? 30 feet for entire digestive system but only 7 feet for the small intestine(the largest the longest part? is it possible it should read 7metres (22 feet) for the small intestine measurements? Also in reading text.

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