The progress made in fundamental medical research over the past decades, the scientific acquisitions in the field of genetics, molecular biology and biochemistry in relation to the explosive development of investigative technologies have revolutionized the clinical approach to many pathological entities, practically opening a new era in the evolution of clinical medicine. Dental medicine, as a science, feels the massive impact of the needs for knowledge and relaunches the interest of research in all its subspecialties. From this perspective, these are legitimized not only through the crisis in managing the immense volume of information, but also through the openings offered to the framework of conceptualizing and defining the identity of this branch of medicine, related to the need to particularize the specific problems in this discipline. Digestion is a fundamental process in the survival of an organism. It begins in the oral cavity, where the bolus is formed, and continues in the stomach, forming the chyme, which then reaches the small intestine and transforms into the chyle. Through mastication, the surface of food increases, thus the enzymes are able to act more easily on the substrate. The first enzymes to act on food are the salivary ones - salivary amylase, lingual lipase. Mastication is regulated through the contact of food with receptors in the oral cavity. These will send impulses by way of the trigeminal nerve towards the centre of mastication - located in the bolus. From the bolus, they will start the signals on the efferent pathway (trigeminal, hypoglossal and facial nerves) that will reach the masticatory muscles. Mechanical digestion (mastication) can thus begin. Mechanical digestion in the oral cavity results from mastication. During mastication, the food is manipulated by the tongue, crushed by the teeth and mixed with saliva. Concomitant with mechanical digestion, the chemical digestion takes place through the action of saliva. There are two types of salivary glands in the oral cavity: large glands - parotid, sublingual, submandibular and small glands - disseminated throughout the oral cavity. Within 24 hours, up to 1.5 liters of saliva are secreted, 99% of which is represented by water. The remaining 1% consists of enzymes, mucus, nitrogen content. After finalizing mastication, deglutition begins. This mechanical process consists of thrusting the bolus from the mouth towards the stomach, using the esophagus.
Read full abstract