A manual of anatomy . of this section presents the nasal cavity [cavum nasi).This and its connections are described on page 271. At hirth the facial portion of the skull represents only about one- 72 OSTEOLOGY eighth the mass of the cranial portion. The median line junction ofthe frontal and parietal bones is incomplete, constituting the frontalfontanelle (Joniiculus frontalis); this is diamond-shaped, covered in by-membrane and is closed by bone by about the middle of the secondyear. Between the parietal and occipital bones there is also an areawhere the bones are incomplete and this is the p
A manual of anatomy . of this section presents the nasal cavity [cavum nasi).This and its connections are described on page 271. At hirth the facial portion of the skull represents only about one- 72 OSTEOLOGY eighth the mass of the cranial portion. The median line junction ofthe frontal and parietal bones is incomplete, constituting the frontalfontanelle (Joniiculus frontalis); this is diamond-shaped, covered in by-membrane and is closed by bone by about the middle of the secondyear. Between the parietal and occipital bones there is also an areawhere the bones are incomplete and this is the posterior fontanelle{fonticulis occipitalis). This is closed usually by the second monthafter birth. Lateral fontanelles are usually present at the sphenoidalangles of the parietal bones. The parietal eminences are unusuallyprominent at birth and represent the less-marked tubera parietaliaof the adult. The forehead bulges prominently at the regions of the frontal Frontal fontanelle Frontal eminence Sphenoid fontanelle. Parietal eminence Occipital fontanelle Tympanic anmilus Lateral Pyra- Mastoidportion mid fontanelleof occl- fma-pital stoidportion) Sutura mendosa Fig. 49.—Skull of a new-born child seen from the left side. (Sohotla ami UcMurrich.) tuberosities. The apertura pyriformis is relatively wider than in theadult, the maxillae are low and the alveolar margins poorly maxillary sinus is merely indicated by a groove. The mastoidprocess is barely noticeable. The mandible consists of lateral halvesunited by fibrous tissue and the alveolar margin is poorly ramus is wide and the angle is obtuse. In the adult the face constitutes about one-half of the mass of thecranium. This is mainly due to the eruption of the teeth and thedevelopment of the air sinuses. As regards sex, the skull of the average female is smaller than thatof the average male by about one-tenth. It is lighter, smoother andless well marked in regard to ridges for muscle attachment. Theforeh
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecthumananatomy, bookyea
