Interested in understanding how your body digest foods? This article will give you a great introduction into your digestive system and how it works. It's important to understand the digestive processes and the organs that are in play, if you want to optimize your diet and nutrition plan.
What is Digestion?
At a high level, digestion is the process of taking foods you eat and moving them through your digestive system, while allowing your body to absorb the nutrients and convert individual items into energy. Digestion begins when you ingest food and continues until the indigestible components of your food are eliminated. Digestion is made of of two different steps – Mechanical and Chemical. Mechanical digestion begins as you chew your food. Your teeth break the food down into pieces that can be swallowed while your stomach begins the churning action which breaks the pieces down even more. Salivary glands under your tongue help the process by secreting saliva, which helps to moisten and compact the food allowing your tongue to press it down. The Chemical digestive process along your entire digestive tract. This consists of enzymes and bile from the liver dissolve the food, which causes the nutrients from the food to be released.
While most of the digestive system is simply a long tube, the stomach is a smallish pouch which is encircled by muscles. These muscles have cyclic contractions, called peristalsis, which perform not unlike a food processor-turning, churning and grinding your food. At the same that this is going on, your stomach is also secreting digestive juices, helping the digestive processes. So the stomach is basically turning your food into a thick liquid mix which is then ready to travel on down through the small intestine where the majority of the nutrients are absorbed into your system.
The Small Intestine
Even though in relation to the rest of your digestive system, the small intestine may appear small, its actually very long. If you were to uncoil it, you would fine about 20 feet worth of intestine. However, in your body, it's neatly coiled up. And coming from experience, you want it to stay that way. When your partially digested food gets into the small intestine, several new juices are secreted:
- Pancreatic and intestinal enzymes
- Alkaline pancreatic juices
- Intestinal alcohol dehydrogenate
The pancreatic enzymes will complete the digestion of proteins into amino acids. Bile helps to make fats able to mix with water. The alkaline will balance the acidity that came from the stomach while allowing the complex carbohydrates to be broken down into simple sugars. And any alcohol that was not absorbed into your system is digested by the dehydrogenate process.
While all of this is going on, the lining of the small intestine is busy absorbing the nutrients in the food. The lining of the small intestine has a bunch of small fingers or nippple-like feelers that are programmed to absorb a particular nutrient. So nutrients are not processed in their order of arrival, but actually as they are broken down to a specific part and hence can be absorbed. The basic parts are:
Carbohydrates – these are absorbed very quickly as simple sugars
Proteins -which are broken into amino acids, happen next
Fats – These take the longest time to break apart and this is why when you eat a high fat meal you feel so much fuller then a meal made of of a salad
Vitamins – those that can dissolve in water happen much quicker, but the remainder are typically those which dissolve in fat. So you need some fat for this process.
Once you've digested you food and the nutrient have been absorbed, the amino acids and sugars are carried through the bloodstream to your liver where they are processed and sent out. Fatty acids, cholesterol and several vitamins will enter the lymphatic system and be distributed to other areas.
Now that the nutrients in your food has been distributed in your body, at a cellular level the nutrients are burned or metabolized for heat and energy and to repair tissue.
The Large Intestine
I will not go into the large intestine process here, because there is not a lot of nutrition related processes here. but there are some which I'll mention For one, vitamin B12 is manufactured here and absorbed. Also vitamin K is produced here too.
Hopefully, you learned some things about the digestive process and can apply these learnings to improve the quality of your diet.