Digestion is the mechanical and chemical breakdown of our food into small enough molecules, so that they can be absorbed in the intestines and used as nutrients by the body, to help us renew our internal tissues and organs, over our lifetime.
In that last sentence alone, you can see that dysfunction of this process, must mean a detriment to our general health and wellbeing.
The fundamental role of the mouth is to begin the process of digestion, by reducing the size and altering the consistency of our food.
The mouth achieves this by the mechanical action of using the teeth to chew, along with the tongue, to move the food around. Together they help reduce the surface area of food, and create what is called a "bolus".
The bolus is lubricated by the chemical addition of Saliva and mucous from the glands within the mouth, which further help to alter the consistency and surface area of our food.
Certain sensory receptors within the mouth, send signals to the brain to begin the process of digestion, by releasing Saliva and the hormone Gastrin to prepare the stomach to receive the bolus.
Indeed, this anticipatory reaction is also stimulated by the sight, smell and thought of the food we are about to eat. This first phase of digestion is called the Cephalic phase.
During the Cephalic phase, there is only a partial amount of chemical (enzymatic) breakdown of our food that takes place within our mouths, which allows us to taste the foods we eat.
The first part of this process is carbohydrate digestion, which is performed by the action of an enzyme (substance that significantly speeds up a chemical reaction) called Salivary Amalyse. Another enzyme named Lingual Lipase - responsible for fat digestion - is released in the mouth, but only begins its actions once activated in the acidic environment of the stomach.
Alongside its carbohydrate digestive role, Saliva contains antimicrobial substances, because the mouth is the first line of defence between ourselves and any potential pathogens, contained within the food we eat.
In summary, the mouth acts to reduce size and lubricate food for swallowing into the stomach, where the real chemical breakdown process begins.
Chewing our food properly is an often overlooked, but very important consideration, when correcting any detrimental nutrition regime.
The smaller and more liquified the bolus, the better work that the stomach can do in actually digesting it into chyme, and optimally digesting the food we eat......but more about that and the stomachs role in a later post.....next time we discuss the Oesophagus, and a common complication that may arise from its dysfunction, called acid reflux, also known as GERD.