Digestive system and its Functions

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What is a digestive system?

A digestive system is a group of organs that work together to digest the foods we eat. They also absorb nutrients and essential vitamins required for the body.

The absorbed nutrients and minerals are then transported from the digestive system to the circulatory system.

The digestive system is a series of hollow organs that make up the digestive system. The digestive system mainly breaks down the food we eat. It starts from the oesophagus and ends at the anus.

Why is digestion important?

The digestive system plays an important role as it breaks down the food we eat and absorbs the nutrients. Carbohydrates, proteins, vitamins, fats and minerals are absorbed from the broken down food.

The digestive system then distributes the nutrients for various processes like growth, metabolism, cell repair and energy expenditure.

Proteins break into amino acids

When the food enters the stomach, stomach acids and enzymes present will break down the food we eat.

The hydrochloric acid and the enzyme protease break the long protein chains into a small chain of tripeptides, dipeptides and amino acids.

The broken-down protein then moves from the stomach to the small intestine. The enzymes produced by the pancreas neutralise the acids in the food.

Fats break into fatty acids and glycerol

Fats and carbohydrates contribute to the majority of the energy required for the body. Lipase is an enzyme responsible for the breakdown of lipids in the food.

The fat from the food is broken down into two components called glycerol and fatty acids by the process of hydrolysis. This process is called as lipolysis and takes place in the cytoplasm.

Carbohydrates break into simple sugars

Complex carbohydrates are broken into simple sugars. The broken simple sugars are absorbed by the body through the bloodstream.

The simple sugars which are absorbed by the body will increase the sugar level in the blood. At that time, the pancreas will release a hormone, and the excess sugar in the blood will be used during energy expenditure.

Organs of the digestive system

As mentioned above, the digestive system involves a hollow series of organs that complete the digestive system. The organs that contribute to the digestive system are listed below.


The digestive system starts from the mouth. The process of digestion starts before you eat your food. The salivary glands in your mouth and eyes together make you hungry.

It creates a feeling of cravings for us to eat the food. The food we eat is chewed, and the first process of breaking the whole food takes place in the mouth.

The saliva in the mouth and the food we eat mix together. With the help of the teeth, the food is chewed well and is mechanically broken down.

The enzymatic and chemical breakage of food takes place in the stomach.


The oesophagus is a muscular tube that connects the mouth and the stomach. The food that is chewed by the mouth passes through the oesophagus and then to the stomach.

The oesophagus is also called a windpipe. The windpipe contracts and relaxes to move the food through the oesophagus. The food then reaches the stomach for further processing.

When the food cannot pass through the stomach and flows back to the oesophagus, it causes a feeling of heartburn.


The stomach is also called as a container. It holds the food while the enzymes break down the particles by enzymatic action.

The stomach contains a strong line of hydrochloric acid. These acids help to break and digest the food we eat. After the sufficient processing of food, the contents pass to the small intestine.

Small intestine

The small intestine is a twenty-two feet long muscular tube that is made up of three segments— the duodenum, jejunum and ileum.

The small intestine contains enzymes that help break the food released from the liver and the pancreas.

The first segment of the stomach is the duodenum, which breaks the food into small particles. The nutrients from the broken food is absorbed by the jejunum and ileum.

After the processing of the food in the small intestine, the food particles becomes semi-solid. The change in consistency is done by using water, enzymes and bile.

After the absorption of the nutrients, the left-out particles pass through the large intestine for further processing.


The pancreas contains a digestive enzyme that helps to break down fats, proteins and carbohydrates. The pancreas secretes insulin that helps to metabolise the sugar that circulates in the bloodstream.


The liver is a vital organ and is responsible for detoxifying the body from toxins. Apart from detoxifying, the liver has many functions. One such primary job is to process the absorbed nutrients from the small intestines.

The liver is called as body’s chemical factory as it absorbs all the raw nutrients from the small intestine and produces important chemicals the body requires for various processes. The liver secretes a fluid called bile—the bile is a mixture of bilirubin,  bile salts and cholesterol. Bile plays a major role in digesting the fat, vitamins and minerals from the food we eat.

The liver also mitigates the effect of harmful chemicals that can be toxic to the body. Certain drugs may be toxic to our bodies. It breaks down chemically and flushes those substances out of the body.

Gall bladder

The gall bladder contributes an important role in digestion. It stores the bile that is secreted from the liver.

The bile that is secreted by the liver is stored in the gall bladder. The stored bile will be concentrated by the gall bladder and when stimulated it ejects the bile into the lumen.


The colon mainly processes the waste making bowel movement easy. The colon connects the small intestine and the rectum.

The colon regulates the peristalsis. The stool is first in the liquid form, and as it moves through the tract, the liquid is removed and becomes solid.

The waste products will be processed within 36 hours after eating food. The stool is then passed through the rectum, which excretes out of the body.


The rectum is a straight eight-long-inch chamber that connects the colon to the anus. The rectum collects the stool from the colon and holds it till it can be excreted out.

Whenever, the waste is generated, the rectum signals the brain to empty the waste collected in the rectum.


The anus is the end of the digestive system. It pushes the waste out of the body. The anus consists of pelvic floor muscles and two anal sphincters.

The lining in the upper anus will be able to detect the presence of stool and flushes out of the body.

Digestive system conditions

The food we eat determines our physical and mental health, disorders and diseases. Some conditions like constipation and heartburn are common.

The stomach takes time to process the food when we consume acidic foods. As a result, you will have the feeling of bloating and flatulence.


Constipation usually occurs when the food we eat does not have enough fibre. When you consume too much sodium and salts, you might gain water weight and will have the feeling of bloating.

Consume foods that are rich in fibre to avoid constipation. Drinking enough water also makes you excrete the waste out of the body.


Diarrhoea happens when you consume foods that are contaminated by pathogens. Diarrhoea is also caused when you drink unclean water. Consume healthy foods and drink clean water to avoid such health conditions.


Heartburn is caused when you consume too much acidic foods. The acids from the stomach reach your oesophagus and make your oesophagus tract burn. When you have the feeling of heartburn, drink more water and avoid consuming acid foods.


Haemorrhoids are caused when the veins swell in your anus and rectum. This swelling can be painful especially, when you excrete.

Stomach Flu

Stomach flu is an infection that is caused in the stomach. It usually lasts for about 7–10 days. It is a common disease caused by a virus, and proper treatment will cure the condition.


Ulcer can develop in the oesophagus, stomach and stomach lining. The ulcer is caused in the stomach by the bacteria Helicobacter pylori. These infections can be treated with proper treatment.

Gall stones

Gall stones are small pieces of digestive fluid that are accumulated in the gall bladder. Gall stones are formed from bile, bile pigments bile salts, bile acids and cholesterol /calcium, found in the bile.

When bilirubin is produced in excess due to certain conditions, gallstone formation takes place. The excess bilirubin production leads to gallstone formation.

How can I keep my digestive system healthy?

The digestive system plays an important role in the human body. There are certain ways to keep the digestive system healthy.

Drink more water

Keeping yourself hydrated will keep your body healthy. Water combined with digestive juice helps in the digestion of food and avoids concerns related to the digestive system.

Drinking water also helps to lose weight. Sometimes, we confuse the feeling of being thirsty and hungry. Drinking water also helps to cut down the extra calories we consume.

Include fibre in your diet

Fibre helps in easy bowel movement. There are two types of fibre— soluble and insoluble fibre. Consume foods that have both soluble and insoluble fibre.

Eat a balanced diet

A balanced diet should have foods that contain all the minerals and vitamins that are required for our body.

Choose foods that are rich in vitamins, minerals and fibre. Such foods will help in the bowel movement and also keep you full for long time.

Eat foods with probiotics

Probiotics are good bacteria that enhance the gut environment. They also reduce the count of bad bacteria present in the stomach and aid digestion.

Probiotics enhance the immune system. So it is recommended to consume foods that have probiotics. Foods like curd, yoghurt and cheese are good sources of probiotics.

Eat mindfully

Always be aware of the foods you eat. Chew your food properly and then swallow them. We tend to eat fast, and the food may not be chewed properly. This might cause digestion problems.

Sometimes, we might get cravings and tend to eat more. But always be watchful of the quantity and quality of the food you eat.


Physical activity not only regulates your weight but also keep your digestive system healthy. Physical activity increases the blood flow in the digestive tract and helps the food to move through your digestive system, aiding the process.

Avoid alcohol and smoking

Alcohol consumption and smoking can hurt your digestive system. It interferes in the process of digestion and causes ulcers. Smoking increases the risk of cancer and stomach-related problems.

Manage your stress

Stress directly affects your digestive system and slows the process of digestion. It also makes you eat more or eat less. So always manage your stress levels.


The digestive system is important for any organism as the food we eat contains nutrients. These nutrients are absorbed and processed by the digestive system and then transported to other parts of the body.

Consume a balanced diet to avoid deficiency of vitamins and overconsumption of particular nutrients. If you have any digestive system problems, consult your doctor. When you often get digestion problems, try to alter your food habits.

Also, make it a habit to drink water. Make it a habit to drink two litres of water daily. Water consumption will keep you hydrated and prevent digestive problems like constipation.


What are the four digestive systems?

The four regions of the digestive system are the mouth, pharynx and oesophagus, stomach, small intestine and large intestine.

What are the three main functions of the digestive system?

The three main functions of the digestive system are digestion of the food, absorption of nutrients from the food and transportation of the absorbed food to other parts.

How many hours does food stay in the stomach?

The food we eat stays up to 6–8 hours. The process of digestion inside the stomach takes time.

How soon after eating should you poop?

The digestion of food differs from one person to another, and it depends on age, sex and metabolism. Usually, the food stays up to two days before passing out of the body.

What is the fastest food can pass through you?

Foods that are rich in sugar pass the process of digestion quickly. They give you empty calories and make you hungry again.

How many times should you poop a day?

The movement of the bowel is important, and a healthy person can poop up to two times a day.


The Information including but not limited to text, graphics, images and other material contained on this blog are intended for education and awareness only. No material on this blog is intended to be a substitute for professional medical help including diagnosis or treatment. It is always advisable to consult medical professional before relying on the content. Neither the Author nor Star Health and Allied Insurance Co. Ltd accepts any responsibility for any potential risk to any visitor/reader.

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