Practical medicine, with a sketch of physiology and therapeutics : being the fourth edition of Meade's manual for students / by Alexander Silver.

Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: Practical medicine, with a sketch of physiology and therapeutics : being the fourth edition of Meade's manual for students / by Alexander Silver. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    wise, is conveyed into the mouth in various fashions, being sometimes directly introduced by the hand, sometimes sucked in by creating a vacuum in the mouth. In this cavity it is reduced to a pul]} by means of the teeth and mixed with the saliva. In these operations the tongue, teeth, and salivary glands are mainly employed. At the same time the tongue is the main seat of the simple sense of taste—i.e., of the appreciation of salt, sour, sweet, and bitter; the more complex idea of flavour is derived from the upper part of the pharynx and posterior nares. The teeth, in the adult subject, are thirty-two in number, sixteen in each jaw; they are divided into the incisors, cuspidati, bicuspidati, and molars. There are in each jaw fow incisors, two cuipidate, four bicuspid, and six molar teeth. Each tooth is composed of a crown (or projecting part), a neck, and a fang or root. The crown is covered by a very hard substance denominated enamel, and each tooth contains a cavity which is filled with the dental pidp. This receives vessels and nerves through a canal in the root. The incisor and cuspidate teeth have single roots; the bicuspids are distinguished by their double roots; the two anterior molars of the upper jaw are furnished with three roots; the rest (with the exception of the denies sapiential) have usually only two. In the child, up to the age of seven or eight years, there are only twenty teeth-viz., four incisors, two cuspidate, and tour molar teeth in each jaw. The teeth under the microscope appear to be composed oi an external coating, the enamel, which covers the crown of the tooth. That which covers the fang of the tootli is called the cement or crusta petrosa The sub- stance of the tooth itself is composed of dentine, made nili of radiating and branching tubes. The tongue is principally composed of muscular (issue It is covered by a stratified epithelium of the squamous kind and on .ts surface various kinds of projections called papilla; are to be observed. Three kinds of papulae are distinguishable on the surface of the tongue. First, the ealyciform papiUce feapilla vallate, or circumvallate), about,' a, dozen m number, which extend in a double row across the tongue in a V-shape, the angle being formed by the foramen root of the tongue. These are lame in Battened, and surrounded with an elevated rmg of mucous membrane, whence their name. On the outer is 2