An elementary treatise on human anatomy / by Joseph Leidy.

  • Joseph Leidy
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: An elementary treatise on human anatomy / by Joseph Leidy. Source: Wellcome Collection.

    158/960
    is proportionately larger, and more soft and delicate, than later. Be- fore ankylosis of the bones of the skull they are everywhere so in- timately and fitly ai'ticulated that no ordinary violence is sufficient to derange or displace them. Sections made through the cranium in any direction, as illustrated in Pigs. 71-76, exhibit the varied modes of junction of the borders of the bones, which contribute to main- PiG. 73. Fig. 74. Transverse section through the front of THE CRANIUM. 1, transverse areh formed by the frontal bone; 2, great wing of the sphenoid bone, including or overlapping the abutments of the frontal arch; 3, body of the sphenoid bone, with its sinuses. Transverse section in advance of the middle of the cranium. 1, parietal bone form- ing with its fellow an areh; 2, great wing of the sphenoid bone; 3, horizontal portion of the wing; 4, body, with the sphenoidal sinuses. tain the integrity of the whole. The face is a wedge-like segment of a cylinder inserted beneath the narrower extremity of the cranium, against which it is strongly stayed by the orbital and zygomatic arches, the pterygoid processes, and the rami of the mandible. The middle of Fig. 75. Transverse section through the middle of the cranium. 1, parietal bone; 2, squamous portion of the temporal bone; 5, petrous por- tion ; 4, body of the sphenoid bone, with the sphenoidal sinuses. Fig 76. Transverse section posterior to th e mid- dle OF the cranium. 1, back part of the pa- rietal bones; 2, mastoid portion of the temporal bone; 3, mastoid process with the sinuses: 4, petrous portion of tlie temporal; 5, sphenoidal body, or the basilar process. the face is remarkable for its lightness combined with strength. The bridge of the nose, the entrances of the orbits, and the zygomatic arches are all constructed on mechanical principles, giving strength