You probably don’t think about the digestion when you are tucking into your breakfast but the moment you spoon your eggs or porridge into your mouth a complex series of processes begins. In this article Patrick Dale introduces us to the organs that make up this vital biological system and explores the “ins and outs” of the digestive process…

The amazing eight – the organs that make up the digestive system
When thinking about food and eating, it’s all too easy just to focus is on the stomach but in reality digestion involves much more just that one organ…

1)      Mouth – responsible for mechanical breakdown of food through mastication (chewing) and the production of saliva which lubricates food, keeps the mouth healthy and contains enzymes to start the breakdown of carbohydrates

2)      Oesophagus – the hollow tube which connects the mouth to the stomach

3)      Stomach – where chemical breakdown occurs and hydrochloric acid is secreted to kill “bad” bacteria and start the breakdown of tough proteins

4)      Small intestine – primary site for nutrient absorption into the blood

5)      Large intestine – also called the colon. Vitamins, minerals and water are absorbed and waste matter is turned into faeces prior to excretion

6)      Liver – produces bile acids which break down fats so that they can be emulsified (mixed with water)

7)      Gallbladder – stores bile acid produced by the liver

8)       Pancreas – secretes enzymes for the breakdown of protein into amino acids, carbohydrates into glucose and fats into fatty acids and also produces insulin which is necessary for the movement of glucose into the body’s cells.

These organs have numerous functions and work together in the digestive process…

• Ingestion – the taking in of food into the stomach
• Propulsion – the movement of food through the hollow tubes of the gastro intestinal (g.i.) tract
• Digestion – the breaking down of macro nutrients (protein, carbohydrates and fats) into smaller units
• Absorption – the movement nutrients into the blood
• Elimination – the excretion of any waste products out of the body

From A to Z – the passage of food through the digestive system
The very thought of food triggers enzymes (substances that control chemical reactions) to be released and saliva to be produced in preparation for eating – something we’ve all experienced when we’ve found our mouths watering at the thought of eating something we really like! Chewing causes mechanical breakdown our food into smaller pieces which increases its surface area thus making it easier to swallow and digest. Saliva is produced by the salivary glands and lubricates the food for easy passage through the tubes of the digestive system…

On swallowing, the food passes down the oesophagus and into the stomach. The movement of food through the hollow tubular organs of the digestive system is called peristalsis – imagine a snake swallowing an egg! Once in the stomach food is broken down into even smaller units and mixed into a liquid called chyme. When digestion is completed and the chyme is ready, the stomach empties into the small intestine (long in length but small in diameter) where absorption begins. Nutrients are extracted from the chyme by structures called villi and absorbed into the blood for use in the body’s cells.

Once the chyme has reached the end of the small intestine it passes into the large intestine (large in diameter but shorter in length) where water is absorbed and waste material is formed into faeces ready for elimination from the body. 

MOT your digestive system
Just like your muscles, your digestive system needs some care and attention to keep it in top shape. To prevent common digestive problems it is essential to eat well and drink plenty of water. Fibre (found in fruit, vegetables and whole grains) is vital for the easy passage of food through the intestines. Without sufficient fibre and water, the propulsion of matter through the hollow tubes of the digestive system can become sluggish which may result in constipation or less frequent and/or more difficult bowel movements which puts an unnecessary strain on the digestive system. If left unchecked this strain can develop into a condition called diverticular disease where bulges occur in the walls of the large intestine and bacteria builds up resulting in abdominal pain. Fibre and water are key to digestive health.

The bottom line is (pun intended!) eat plenty of fresh fruit and vegetables, whole grains in preference to refined grains, drink plenty of water, take care with food hygiene and exercise regularly and you’ll be fit on the inside as well as the outside!

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