Mouth organ

“ Deglutition.—Deglutition, or swallowing, is the process by which food is transferred from the mouth to the stomach. Though this is not, strictly speaking, a digestive process, it is, nevertheless, necessary for the further digestion of the food. Mastication and insalivation, which are largely mechanical, prepare the food for certain chemical processes by which it is dissolved. The first of these occurs in the stomach and to this organ the food is transferred from the mouth. The chief organs concerned in deglutition are the tongue, the pharynx, and the esophagus. ”

“ An agent acting upon the mucous membrane of the mouth, stomach, or intestine, may produce in the nervous system important effects as regards digestion, and yet we may have no sensation of this either through taste or through smell, its parts not entering into communication with the central organ of sensation. ”

“ In the floor of the mouth, between the two branches of the lower jaw, and supported behind by the hyoid apparatus, lies the tongue, an organ the free surface of which, especially in its posterior part, is devoted to the sense of taste, but which by reason of its great mobility (being composed almost entirely of muscular fibres) performs important mechanical functions connected with masticating and procuring food. Its modifications of form in different mammals are numerous. ”

“ The digestive system includes every organ, function and process concerned with the utilization of food-stuffs, from the moment of their entrance into the mouth, their preparation in the canal, assimilation with the tissues, their employment therein, up to their excretion or expulsion in the form of waste. Each portion resembles a link of a continuous chain; each link depends upon the integrity of the others, the weakening or breaking of one straining or making impotent the chain as a whole. ”

“ By this contrivance the organ is rendered more fit for perceiving such odours, and is preserved from being injured by those that are more strong or corrosive. Many other receptacles of peculiar fluids disgorge their contents, when the ends of their ducts are stimulated; as the gall bladder, when the contents of the duodenum stimulate the extremity of the common bile duct: and the salivary glands, when the termination of their ducts in the mouth are excited by the stimulus of the food we masticate. ”

“ These glands consist of clusters of very small pouches, around which a delicate network of blood-vessels is arranged: they empty into the mouth by means of little tubes, or ducts. The flow from these glands is at all times sufficient to maintain a soft and moist condition of the tongue and mouth; but when they are excited by the presence and taste of food, they pour forth the saliva more freely. ”

“ Well, then, you must suppose a body shaped like a short cylinder, the top cut off, and in the top a hole rather oval than round. All round this aperture, which is the mouth, imagine that there are placed a number of feelers forming a circle. The cavity of the mouth leads into a sort of stomach, which is very unlike those of the higher animals, in the circumstance that it opens at the lower end into a cavity of the body, and all the digested matter, converted into nourishment, is thus distributed through the rest of the body. That is the general structure of one of these sea anemones. ”

“ The teeth divide solid food, the glands which line the inside of the mouth moisten it, the tongue mingles the food, presses it against the palate so as to force out the juice, and then collects the elements in the centre of the mouth, after which, resting on the lower jaw, it lifts up the central portion forming a kind of inclined plane to the lower portion of the mouth where they are received by the pharynx, which itself contracting, forces them into the oesophagus. ”

“ The tongue is simply a "tongue-shaped" bundle of muscles, covered with a thick, tough skin of mucous membrane, dotted all over with little knob-like processes called papillæ, which are of various shapes, but of no particular utility, except to roughen the surface of the tongue and give it a good grip on the food. If the mucous "skin" covering the tongue does not shed off properly, the dead cells on its surface become thickened and whitish, and the germs of the mouth begin to breed and grow in them, forming a sort of mat over the surface. ”

“ Further, it is easy to see how thorough mastication of food may prolong mechanical stimulation of the salivary glands and thus increase the flow of the secretion, while the longer stay of sapid substances in the mouth cavity increases the duration of the chemical stimulation of the sensory fibres of the lingual and glossopharyngeal nerves. ”

“ In any single act of inspiration the mouth is opened, and the oral cavity enlarged by the lateral expansion of its walls. When the oral cavity is filled with water, the mouth is closed and the expiratory process begins. By the lateral contraction of the oral walls the water is driven outwards through the gill-clefts, and over the gill-lamellae. During this process the branchial arches become widely separated by the contraction of their muscles, the operculum is elevated, and the oesophagus is closed by the contraction of its muscular wall. ”

“ The teeth.—Imperfect use of the teeth leads to many ills. When adequately exercised and made to execute for one or two hours every day a lively dance in their sockets, during which the circulation of blood and lymph in the tooth-pulp, periodontal membrane, and surrounding tissue of the gum is vigorously stimulated, and the cavity of the mouth is bathed in a copious flow of salivary and other buccal secretions, we have conditions which make alike for the health of the buccal mucous membrane, of the teeth, and of the periodontal membrane and alveoli ”

“ Anatomy teaches us, that the skin is a continuation of the membrane which lines the stomach; and your own observation will inform you, that the delicate linings of the mouth, throat, nose, and eyes, are nothing more. Now some people acquire preposterous noses, others blotches on the face and different parts of the body, others inflammation of the eyes—all arising from irritation of the stomach. People laugh at me for talking so much about the stomach. ”

“ Hence a psychic event, the eager longing for food, must be accepted as an undoubted excitant of the nervous centre for the salivary glands. On the other hand, the same every-day experience, as well as numerous experiments upon animals, teach us that a number of substances, when brought into contact with the mucous membrane of the mouth, are likewise able to call forth a secretion of saliva. ”

“ The senses of hearing, taste, and smell, are frequently much impaired in corpulent people, a condition due in the majority of cases, according to Dr. Harvey, to deposits of fat in the organs concerned. The nasal passages, mouth, and throat, are, as all know, lined with mucous membrane, which continues through the Eustachian tubes into the middle ear. This mucous membrane may become the seat of a fatty deposit, and thus impair the function of the part. ”

“ The mucus which constantly forms on the lining membrane of the nose and the little hairs in the nostrils, act as screens, preventing dust being breathed into the lungs. The pharynx is the cavity behind the nose, mouth and larynx. ”

“ The Mouth is formed by the intermaxillary and maxillary bones, or by the intermaxillary only in the upper jaw, and by the mandibulary bone in the lower. These bones are either bare or covered by integument, to which frequently labial folds or lips are added. As regards form, the mouth offers as many variations as the body itself, in accordance with the nature of the food, and the mode of feeding. ”

“ The true skin is 1/12 to 1⁄8 of an inch in thickness, but in certain parts, as in the lips and ear passages, it is often not more than 1/100 of an inch thick. At the orifices of the body, as at the mouth, ears, and nose, the skin gradually passes into mucous membrane, the structure of the two being practically identical. As the skin is an outside covering, so is the mucous membrane a more delicate inside lining for all cavities into which the apertures open, as the alimentary canal and the lungs. ”

“ To get a correct idea of the throat we should look into the wide-open mouth of some friend. Depressing the tongue we can readily see the back wall of the pharynx, which is common to the two main avenues leading to the lungs and the stomach. Above, we notice the air passages, which lead to the posterior cavities of the nose. We have already described the hard palate, the soft palate, the uvula, and the tonsils (Fig. 46) . ”

“ The limbs stiffen, tremble or twitch, the head is extended or flexed, or jerked, violently striking the ground, the mouth open, with abundant saliva, or firmly closed though the tongue may be between the teeth. ”

“ The internal furnishings of the body include a stomach and complete digestive system, along with a very peculiar set of jaws or teeth, lying just within the mouth, the points or tips of the jaws being usually protruded from the mouth-opening. ”

“ The bright eyes become dull and fishy, and the skin loses its glossy smoothness. In time a slight break appears to run in the line of demarkation between the mucous membrane of the mouth and the outer skin, along the edge of the lips. ”

“ Hence there is, as we see, many varieties in the degrees of the extensibility of the mucous system; it is the same with regard to the contractility of texture. These two110 properties are besides capable of being put rapidly into action. We know that the stomach, the intestines, the bladder, &c. pass in an instant from a great size to extreme contraction. Their functions even suppose this rapidity, without which they could not be performed. The palatine membrane which lines the cheeks, exhibits the same phenomenon when the mouth is filled with air, aliments, &c. ”

“ These glands have a great number of apertures for the discharge of the secreted humour into the mouth: hence it will be understood that, if the stomach, or the glandular system, be in a disordered state, the palate likewise will become corrupted; and, that persons who continually stimulate their appetite with heating drugs, spices, liquors, &c. cannot expect to possess either a natural relish for plain and wholesome food, or a good digestion.—See Mastication. ”

“ At the front end of the body is seen the median eye (ce.) , o is the mouth, Ph. the pharynx, œs. the narrow œsophagus, compressed between the supra-œsophageal (supr. œs.) and infra-œsophageal (infr. œs.) brain mass, which opens into the large alimentary canal (Al.) ; Olf. pass. is the olfactory passage to the mouth, lined with thick-set, very fine hairs, which spring from the hypostome (Hyp.) as well as from the large conspicuous camerostome (Cam.) , which limits this tube anteriorly. ”