DIGESTIVE SYSTEM OF HUMAN BODY

In this article, we will be covering the following topics regarding the Digestive system of Human body:

1. What happens to the food we eat?
2. What are the Roles of various organs in the digestive system of humans?

Across the whole planet, average human eats about 1-2.7 kg of food a day which makes it around 365 kgs per year per person and more than 28800 kgs throughout a lifetime, every gram of this food makes its way through the digestive system comprising of different organs.

The digestive system is considered one of the most diverse and complicated systems in the human body.

Its organs work continuously to complete a singular task transforming the raw materials of your food into the nutrients and energy in order to keep you alive.

WHAT HAPPENS TO THE FOOD WE EAT?

The digestive process of food begins before even it hits your tongue. Anticipating a tasty morsel, glands in your mouth starts to pump out saliva. We produce around 1.5 liters of this liquid every day.

Once food enters into the mouth, chewing combines with the sloshing saliva to turn food into a moist lump called the BOLUS. Enzymes present in the saliva breakdown any carbohydrates.

Then your food finds itself at the lip of a 25-centimeter long tube called the ESOPHAGUS, down which it must plunge to reach the stomach.

Nerves in the surrounding esophageal tissue sense the bolus’s presence and trigger peristalsis, (a series of defined muscular contractions) that propels the food into the stomach, where it is left at the clemency of the muscular stomach walls, which bound the bolus, breaking it into chunks.

Hormones released by cells in the lining, trigger the release of enzyme-rich juices and acids from the stomach wall that start to dissolve the food and break down its proteins.

These hormones also alert the liver, pancreas, and gall bladder to produce digestive juices and transfer BILE, (a yellowish-green liquid that digests fats) in preparation for the next stage.

After three hours inside the stomach, the once shapely bolus is now a frothy liquid called chyme and is ready to move into the small intestine.

The liver sends bile to the gall bladder which secrets it into the first portion of the small intestine called the DUODENUM.

Here, it dissolves the fats drifting in the slurry of chyme. So, they can be easily digested by the intestinal and pancreatic juices that have leached onto the scene.

These enzyme-rich juices breakdown the fat molecules into fatty acids and glycerol for easier absorption into the body.

These enzymes also carry out the final deconstruction of proteins into carbohydrates and amino acids into glucose.

This happens in the small intestine’s lowermost regions, the JEJUNUM and ILEUM, which are coated in millions of tiny projections called VILLI.

These create a huge surface area to maximize molecular absorption and transference into the bloodstream.

The blood takes them at the end of their journey to feed the body’s organs and tissues. But it’s not over quite yet.

Leftover fiber, water, and dead cells sloughed off during the process of digestion make it into the large intestine, also known as the COLON.

The body drains out most of the leftover fluid through the intestinal wall. what’s left is a soft mass called STOOL.

The colon squeezes this waste product into a pouch called the RECTUM, where nerves sense it expanding and tell the brain when it’s time to expel the waste.

The byproducts of digestion are expelled through the ANUS and the food’s long journey typically lasting between 30-40 hours is finally complete.

WHAT ARE THE ROLES OF VARIOUS ORGANS IN DIGESTIVE SYSTEM OF HUMANS?

1. THE MOUTH

   The mouth has several functions, Teeth are used to breakdown the food into smaller parts so that they can be digested more easily when they go further down along the digestive path.

   Glands in the mouth produce saliva which contains its own digestive juice which is used to breakdown carbohydrates.

2. THE ESOPHAGUS

   The esophagus is a muscular tube type structure connecting the throat with the stomach. It is about 22cm to 25 cm long and is lined with moist pink tissue called the mucosa.

3. THE STOMACH

   The stomach has 3 main functions and those are :

   • It acts as temporary storage for food which is coming from the esophagus, typically food remains inside the stomach for about 2-4 hours depending upon the type of food we consume.
   • The food is mixed and broken down by the contraction and relaxation of the muscles in the stomach.
   • To secrete Hydrochloric acid and enzymes which helps in the digestion of food.

4. SMALL INTESTINE

   The small intestine is an organ in the digestive system where most of the absorption of minerals and nutrients from food takes place. It is about 6 meters in length and lies between the stomach and the large intestine. It receives pancreatic juice and bile through the pancreatic duct to help in digestion.

5. LARGE INTESTINE

   The large intestine has 4 major functions:

   • Reabsorption of mineral ions such as sodium and chloride and water.
   • Formation and temporary storage of faeces.
   • Bacterial fermentation of indigestible materials.
   • Maintaining a healthy population of more than 500 species of bacteria.

6. RECTUM

   The rectum is the end part of the large intestine with an average length of about 10-15cm. It acts as temporary storage for stool, sensors send messages to your brain to pass the stool.

   

7. ANUS

   The Anus is the last/end part of the digestive tract. Its function is to control the ejection of faeces and unwanted semi-solid matter produced during the process of digestion. It is a 2-inch long canal consisting of two anal sphincters and the pelvic floor muscles.

So, in this article, we learned about How the Digestive System of Human works? and we also learned about the functions of various organs of the digestive system.

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