The class-book of anatomy : designed for schools, explanatory of the first principles of human mechanism, as the basis of physical education . — Os frontis. Having remarked that the skull is composed of eightbones, it is only necessary to describe them individually,in a very general manner. The os frontis is a singlebone in the adult, though in infancy it was in two pieces. ANATOMICAL CLASS BOOK. 11 Though thin and delicate, it is in two plates, whose flatsurfaces have between them a porous space, called diploe,where the blood vessels are safely lodged for nourishingit. Over each eye, it throw
The class-book of anatomy : designed for schools, explanatory of the first principles of human mechanism, as the basis of physical education . — Os frontis. Having remarked that the skull is composed of eightbones, it is only necessary to describe them individually,in a very general manner. The os frontis is a singlebone in the adult, though in infancy it was in two pieces. ANATOMICAL CLASS BOOK. 11 Though thin and delicate, it is in two plates, whose flatsurfaces have between them a porous space, called diploe,where the blood vessels are safely lodged for nourishingit. Over each eye, it throws out a protuberance, marked .by the eyebrows ; — and within the orbit, a thin sheet-like process juts backward, to support the brain frompressing on the globe of the eye. Between the two plates,on a vertical line with the nose, and just between thearched ridges, the two plates recede from each other, sofar as to leave a large cavity, — the frontal sinus, whichfreely communicates with the two nostrils, although a par-tition, extends from the nose up through the chamber. Onthis apartment, seems to depend the strength of the Explanations of Fig. 3. Front view of the singlabone constituting the fore-head : a, a, mark the place ofthe frontal sinus, or vocalcavity: b, the temporalridge; c, the nasal process,where the bones of the noseare joined ; e, e, the externalangular processes f, f, theorbitar plates, above the eye,to sustain the brain. It is a drum-barrel, in effect, being for the purpose ofreverberating the sound, by which its sonorous power iaincreased. While suffering from a severe cold, the char-acter of the voice is changed, and it is usual to remarkthe person talks through the nose. This alteration, how-ever, is to be imputed to the closing up of the passage,between the nose and sinus, which wholly prevents thesound from penetrating the only spot in which its volume 12 ANATOMICAL CLASS BOOK. or tone can be increased. Snuff takers, by the practiceof a vile h
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Keywords: ., bookcentury1800, bookdecade1830, booksubjectanatomy, bookyear1834
