Anatomy, physiology and hygiene for high schools . s, as it is only in these ani-mals that the two sets are used for such different purposes. The skull, or skeleton of the head and face, rests by its pos-terior bone, the occipital bone, upon the upper bone of thespine, the atlas. It iscomposed of twenty-eightbones. Eight of theseform the cranium, six theears, and fourteen theface. The cranium is abox for the protection ofthe brain. It is composedof a basal occipital (Latino5, against, and caput,head) lyone, which restsupon the spine; two pa-rietal (Latin paries, awaU) bones, one on eachside, f
Anatomy, physiology and hygiene for high schools . s, as it is only in these ani-mals that the two sets are used for such different purposes. The skull, or skeleton of the head and face, rests by its pos-terior bone, the occipital bone, upon the upper bone of thespine, the atlas. It iscomposed of twenty-eightbones. Eight of theseform the cranium, six theears, and fourteen theface. The cranium is abox for the protection ofthe brain. It is composedof a basal occipital (Latino5, against, and caput,head) lyone, which restsupon the spine; two pa-rietal (Latin paries, awaU) bones, one on eachside, forming the crown;two temjyoral (Latin tempora, temples) bones, one on eachside5 a. frontal (Latin/>0)is, forehead) bone, forming the. Skull, a, frontal bone; b, parietal; c, temporal; cl,lower jawbone; e, eye socket; /, canal of ear. 48 PHYSIOLOGY AND HYGIENE forehead; a sphenoid (Greek sj^hen, wedge) bone at thebase, with an ethmoid (Greek ethmous, sieve ) bone in frontof it. Foramina (Latin foro, bore a hole )• In the occipitalbone is a large opening, the foramen magnum, through whichthe spinal cord enters the spinal canal. In the temporalbones are the openings to the ear cavities. Openings for thepassage of the cerebral nerves occur in several of the apertures are csMed foramina. As the object of the cranium is protection, the bones arefirmly united to one another by immovable joints, called sn- tures (Latin snere, tosew). In these suturesthe edges of the bones arefor the most part dove-tailed, the projections ofone bone edge fitting thehollows of another. Thesutures can be easily feltupon a babys head. Thebones are hard and thin,and are placed togetherto form an arch. Thecharacter of these bonesand
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