Digestion: The Function Of The Digestive System

A freshly baked apple pie has just been pulled out of the oven. Even before you see it, the aroma of the pie has filled your home. The sweet perfume of the bubbling Honeycrisp apples mixed with the tangy smell of the Grannysmith draws you into the kitchen. The pie is too hot to touch, so you just stand there watching it. You stare as the sugary syrup from the apples drips down the sides of the pie. You cannot tear your eyes away from the golden pie pastry bursting with apples. The pie seems to call to you, “Come over here. Come taste me, just one bite.”

Is your mouth watering yet? Even before you take a bite of food, your digestive system swings into action. Just the sight or smell, even an enticing description, of some delicious food is enough to make you start salivating and producing stomach acids.

Your digestive system is a made up of the gastrointestinal (GI) tract—also called the digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, tube from the mouth to the anus. The main purpose of the digestive system is to break food into smaller substances that your body can use for energy.

After you take your first bite of pie, chemical digestion begins in your mouth. The salivary glands here produce enough digestive juices (saliva) to begin breaking the food down chemically. The saliva moistens the food and helps you chew, taste, and swallow. Besides the salivary glands in the lining of your mouth, you have three pairs of larger salivary glands — the parotid, sublingual and submandibular glands. Together they produce 2 to 4 pints of saliva a day. The basic secretory units of salivary glands are clusters of cells called an acini. These cells secrete a fluid that c...

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...acts and relaxes to mix and digest the food. The respiratory and digestive system work closely together to make energy. The respiratory system brings in the oxygen needed to make energy and the digestive system obtains the nutrients needed to make energy. The digestive system has the closest relationship with the circulatory system. As the digestive system breaks down food, it absorbs nutrients into the blood stream. The circulatory system then transport the nutrients attained through the digestive system to the rest of the body. In a more obscure way, the nervous system, specifically the medulla, controls all of the involuntary actions made throughout the digestive process. Finally, the endocrine system release many hormones that affect the digestive process. These hormones single when certain enzymes should be used and when certain nutrients should be absorbed.