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Digestion is an important body process where the food we eat, gets converted into substances which can be absorbed by the body. Many different organs together form the digestive system, these organs work together to digest the food.


You can refer to the below digestive system diagram, for better understanding.

Now let us look at the basic structure and functioning of this system - from the food entering the body through mouth, till it gets excreted in the form of feces, which is poop!

Labeled Digestive System Diagram

Labeled Diagram of Human Digestive System

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Journey of the Food

oneChewing of the Food
mouth
When you are chewing the food the saliva in the mouth, helps to breaks down the chemicals in the food to a small extent. This process makes the food mushy and easier to swallow, the movement of the tongue while chewing helps to move the food around, and the teeth help to chew the food. When the food is enough mushy, the tongue pushes small amounts of the mushed-up food (called bolus) inside the throat. There are also certain enzymes in the body which help in digestion, some of which are even present in the saliva.

twoTraveling Through the Esophagus Pipe
esophagus
The tongue pushes the bolus in the opening of the esophagus, which is a 25 centimeter long, stretchy pipe; which you can see in the digestive tract diagram. However, at the back of the throat there are two openings, one is the windpipe and the other is the opening of esophagus. A small flap called epiglottis, opens the opening of the esophagus to pass the food, and makes sure that the food doesn't go down the windpipe. But, many times if you eat too fast, you can swallow air with the food and get burps! This happens because swallowed air along with the food or liquid, which enters the stomach is pushed out through the esophagus. The food in the esophagus moves in a wavy path slowly, which takes around 2-3 seconds.

threeIn the Stomach
stomach
The food after passing the esophagus pipe, enters the stomach, which is like a tilted 'J' shaped organ, as shown in the diagram. The stomach forms an important part of the digestive system; imagine a big house which keeps mixing and mashing all the mashed-up food, and helps to maintain digestive health. The stomach performs 3 major functions; it stores the food, it breaks down the mashed-up food into a liquid mixture, and slowly passes this mixture in the small intestine. The strong muscles in the walls of the stomach and the acidic gastric juices, help to break down the food, these juices also kill the bacteria present in the food.

fourPassing the Small Intestine
small intestine
Small intestine is not small in length at all, but just called small intestine because it is small in width. It is actually a long tube, and an adult's small intestine is around 22 feet long! The digestive system provides the building blocks or important nutrients to the muscular system. The small intestine along with 3 more organs, which are the pancreas, liver, and gallbladder further break down the food to absorb all the essential nutrients like vitamins, minerals, carbs, proteins, and fats in the food. The blood comes to the liver, and the liver filters-out the harmful and waste substances. Liver is the largest organ in the body (after the skin), and it performs more than 500 functions.

fivePassing the Large Intestine
large intestine
Large intestine anatomy is fatter compared to the small intestine, and if spread out would measure 5 feet. The large intestine function in digestion is to separate the waste food into solids and liquids, of which the solid waste comes out as feces.

Well, this was all about the organs of the digestive system and their functions. So, just remember the order of the digestive system, the name of the organs, and their functions and you will be able to remember everything about this system easily.

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Blank Digestive System Diagram
Here, is a blank digestive system diagram for you to label and practice.

Printable Digestive System Diagram - Print to Label

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Some Fun Facts
cow

» Here's something interesting you should know. A cow's digestive system is quite complex. It's stomach is divided into four parts.

The first part helps to soften the food, the second sends the food back to the mouth where it get chewed again, the third part removes moisture from the food, and the last which is fourth part mixes the food with digestive juices. Complex, right?

» Birds have two sections in their stomach, one acts as a storage room for excess; because, birds can't eat too much food in one go.
bird


» So, why do we get a feeling of butterflies in the stomach? The fluttery feeling in the stomach is caused when you are nervous or excited. They say during such emotions the adrenaline is released which pulls the blood from stomach and transfers it to the muscles.

This causes the feeling of butterflies in the tummy. If you experience this, then just breathe deeply, and within minutes you will be okay.
butterflies in the stomach


» Clams belong to a group of animals known as 'filter feeders'. They take in water and filter out the food particles using two valves. One valve filters out food from the water, while other filters out water. This keeps happening throughout their life! Must get tiring, I guess...

» You must have observed that students of biology dissecting frogs for study. This is because the digestive system and many other systems in the frog's body resemble that of a human being.
frog


» Sloths are slow, real slow. But, did you know that even their digestive system works slowly? It can take up to a month to process food in its digestive system.

» Did you know that a full-grown horse intestines are 90 feet long?
rumbling stomach


» Ever wondered why we get growling sensation or rumbling sound in the stomach when we are hungry? The rumbling sound is caused due to contraction of stomach and intestines.

However, when we don't have food the rumbling sensation can be heard, because if there is food in the stomach the sound gets muffled.

» Did you know that the food you eat, gets cooled or warmed in the mouth till it reaches an appropriate temperature?
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Digestive System Terms

Absorb: To take something in, can be a liquid or other substance.

Alimentary Canal: It is a passage through which the food passes.

Anus: It an opening at the end of digestive system, from which the waste matter exit.

Appendix: It's a tube-shaped sac, which is joined to the lower end of the large intestine.

Bile: It is a yellowish-green fluid which is secreted by the liver and gets stored in the gallbladder.

Digestive System: This system helps to absorb food in the body, and get rid of waste (feces) from the body.

Epiglottis: It's a small flap located at the back of the tongue, it opens at the opening of the esophagus to pass the food, and ensures that the food doesn't go down the windpipe.

Esophagus: It is a long tube that connects mouth and the stomach, food passes from mouth to stomach via this tube.

Gallbladder: It's a small organ which is below the liver. It is sac-shaped and stores bile.

Gastrointestinal Tract: Also, referred as GI tract or digestive system is an important body system which absorbs food and gets rid of waste.

Liver: Liver is the biggest organ in the body after skin. This organ helps in digestion and removes waste products and worn-out cells out of blood.

Mouth: The top opening of the digestive tract, starts with lips and includes tongue, teeth and gums.

Pancreas: It is a large gland located behind the stomach, it helps to secrete digestive enzymes into the duodenum.

Rectum: The last section of the large intestine, which stores solid waste.

Salivary Glands: They are located in the mouth and help to create saliva.

Stomach: A sac-shaped organ which is attached to the esophagus, it helps to break down and digest the food.

Small Intestine: It forms a part of the digestive tract and is between the stomach and the large intestine.

Large Intestine: It is attached to the small intestine, and is wider than the small intestine. It helps to absorb water from the waste.

Trachea: It is also known as windpipe, and is a tube-like part of the respiratory tract.

Lactose Intolerance: Lactose is a type of sugar present in milk and dairy products. Some people can't tolerate it, and on consuming such foods suffer from symptoms like bloating and gas.

Heartburn: Backward flow of fluids from stomach to the esophagus, causes a warm sensation in the upper abdomen.

Enzymes: These are proteins which help to speed up a chemical reaction.

Saliva: Watery secretion in the mouth due to salivary glands is called saliva.

Stool: It is the solid matter which is discharged by the anus.
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Quiz

Q1. Where does the digestion start?

Stomach
Mouth
Liver
 

Q2. The stomach is shaped like which letter?

J
Z
K
 

Q3. How long is the small intestine?

35 feet
22 feet
10 feet
 
food down the pipe

Q4. Which is the largest organ in the human body after skin?

Large Intestine
Stomach
Liver
 

Q5. The food passes from mouth to _____ and then to the stomach. Fill in the blank.

Esophagus Pipe
Small Intestine
Pancreas
 
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Now that you know so much about digestive system and understand that it is an important system in the body, make sure you follow healthy habits to maintain your digestive system.

Keep eating a lot of fresh fruits and vegetables, as they are rich in dietary fiber. Dietary fiber helps to clean the intestines by removing fats and aids in digestion. Also, drink plenty of water throughout the day to keep yourself hydrated. Keep yourself active by playing outside and doing activities like running, jumping, or other sports. Following such habits will keep your digestive system functioning smoothly and keep you in great health.