PALATE, is the partition which separates the cavity of the mouth from that of the nose, forming the roof of the one and the floor of the other. In man it is composed of two portions, which are called respectively the hard and the soft palate: the former is made up of the inferior or palatine processes of each superior maxillary bone and palate hone, which, meeting in the middle line of the body, form a somewhat flattened arch over the mouth; the latter consists of a membranous curtain of muscular and cellular tissue, of which one margin is attached to the posterior border ot the hard palate, and the other, with the uvula apponded to its middle, hangs loosely backwards into the cavity of the pharynx. Both ibe hard and the soft palate are covered by a thin layer of vascular mucous membrane, immediately beneath which there are numerous minute glands. On each side, the soft palate is continued downwards in two diverging and arched membranous folds (the arches of the palate), which form the lateral boundaries of the fauces, and between which on each side the tonsil lies. Beneath these folds are muscles passing from the soft palate to the sides of the tongue and pharynx.
The hard palate serves as a firm support ngainst which the food may be pressed by the back of the tongue during mastication; and it is by the various actions of the tongue upon it that we articulate several letters, as d,g,j, k, q, &c. The soft palate is capable of such motions by the contractions of its muscles, that it can cither be raised so as to close the passage from the pharynx to the nose and Eustachian tube, or be depressed so as (with the assistance of the tongue) to close the passage from the pharynx to the mouth, or even to close both those apertures. By a simultaneous descent of the soft palate and contraction of the lateral arches by which it is connected with the tongue, the food when forced to the back part of the latter organ is impelled into the pharynx, constituting the first part of the act of swallowing. The soft palate is also of great importance in the actions by which substances are expelled from the digestive and respiratory organs through the mouth or nose, directing their passage, according to circumstances, into one or other of those cavities, as in coughing, sneezing, vomiting, &c.
The chief affection to which the palate is liable is that called cleft palate, a congenital malformation of the same nature as hare-lip [hare-lip], in which a fissuie extends along more or less of the palate, and forms an unnatural communication between the mouth and the nose. Such a fissure may extend from the back of the teelh through the' whole of both the hard and soft palates, or it may consist only in a small aperture in one or other of them. It may also vary in width, and may incline more or less to either side. According to its size, it produces inconvenience by allowing the passage of substances from the mouth to the nose, or in the opposite direction, and by impairing the speech by permitting the air impelled towards the front of the mouth to pass through the nose: hence the peculiar nasal and blowing sound by which the speech of persons thus affected is distinguished. Various operations have been proposed for the cure of this deformity. Those on the soft palate are conducted on the same principles as the operation for hare lip, modified so as to meet the peculiar difficulties which arise from the position of the part. Those on the hard palate consist of either cauterising the edges of the fissure, or endeavouring to make a portion turned up from the adjacent membrane, to adhere to its edges. No operation however can be performed on the hard palate with any hope of success when the fissure is extensive; and the results of those on the soft palate are generally very uncertain. The patient must usually be contented with the palliation that is afforded by a false palate, which consists of a plate of gold or silver adapted to the roof of the mouth so as to cover the aperture in it, and fixed there either by springs and wires attached to the teeth, or by sponge passed through the aperture into the nostril.
Note - this article incorporates content from The Penny Cyclopaedia of the Society for the Diffusion of Useful Knowledge (1840)