Digestion
Digestion is often glossed over in terms of overall health but where ever you find a poorly functioning immune system, for example, you’ll invariably find a compromised digestive system.
It is not well understood but the digestive tract effectively makes up about 70% of the immune system function. If the digestive system is working well then the bacteria, viruses and micro/macro organisms won’t even be able to start to work.
Lets look at the components of the digestive system:
- Mouth – this is where the food is broken down into smaller chunks and mixed with some early acting enzymes. The most common enzyme is Ptyalin which converts starch to glucose in a few minutes. Try this test, take a small piece of white bread and mix it with some saliva in the mouth – leave it in the mouth for just a minute or so and it will go sweet – the starch has begun to be converted to glucose. The mouth is also one of the places where glucose and other plant carbohydrates can be absorbed directly into the blood stream.
- Oesophagus – this is the tube that runs from the back of the mouth to the entrance of the stomach. Although it is just a tube it is complex and has a peristaltic muscle that moves food down in waves. It is very sensitive to a back wash of acid from the stomach – heartburn.
- Stomach – the stomach is essentially a bag that expands and contracts as food enters and leaves. In the stomach acids begin to break down proteins ready for digestion by enzymes further down the gut. Enzymes, acidic tolerant varieties, are also secreted into this container to kick start the process of digestion. The stomach is essentially acidic and does little to digest carbohydrates. If food is not adequately processed in the stomach it can begin to ferment and produce gas which can lead to a feeling of being bloated.
- Small intestine – this part of the digestive tract is actually the longest around 22 feet or 7 metres. It is made up of the duodenum, jejunum, and ileum – the duodenum is where food is further broken down and digested and the jejunum and ileum are where the nutrients are absorbed into the blood stream. During the passage of the food through the small intestine it gets progressively less solid due to the digestive processes and the addition of bile, water and the removal of nutrients. The remaining non nutrient waste is then passed onto the large intestine of colon.
- Pancreas – the pancreas produces and secretes enzymes into the first part of the duodenum and it’s here that broken down proteins, fats, oils and carbohydrates are digested still further ready for absorption in the jejunum and ileum. The pancreas also provides Insulin which although strictly a hormone works as an enzyme and it’s sole purpose is to get glucose out of the blood system and into cells/tissue.
- Liver – the liver takes the majority of nutrients from the jejunum and ileum and effectively reassembles the nutrients into what the body is looking for. It also removes harmful chemicals. Bile secreted by the liver is also vital in the digestion of fats and oils.
- Colon – the large intestine is actually about 6ft or 2 metres long and is the place where water is removed and reused and waste is stored prior to excretion. The colon is home to billions of bacteria which perform several useful functions, such as synthesizing various vitamins, processing waste products and food particles, protecting against harmful bacteria and actually digesting specific fibres and converting some key carbohydrates into vital forms for the body. When the descending colon becomes full of stool, or faeces, it empties its contents into the rectum to begin the process of elimination.
- Rectum and Anus – I’ll leave that to your imagination but it is essentially a holding mechanism prior to elimination.
The digestive system is both complex and central in terms of health and following articles deal with specific areas in more detail.
