Bone markings of the skull9/26/2023 Situated between, and connecting the superciliary ridges, is a smooth, somewhat triangular area, the glabella, below which the nasion ( frontonasal suture) can be felt as a slight depression at the root of the nose.īelow the nasion the nasal bones, scantily covered by soft tissues, can be traced to their junction with the nasal cartilages, and on either side of the nasal bone the complete outline of the orbital margin can be made out. In some cases the prominence of the superciliary arches is related to the size of the frontal sinuses, but frequently there is no such relationship. Below the frontal eminences the superciliary arches, which indicate the position of the frontal sinuses, can be recognized as a rule they are small in the female and absent in children. Near the line of the greatest transverse diameter of the head are the parietal eminences, one on either side of the middle line further forward, on the forehead, are the frontal eminences, which vary in prominence in different individuals and are frequently unsymmetrical. Finally, it curves downward, and forward, and passing above the external acoustic meatus, ends in the posterior root of the zygomatic arch. It can then be traced across the parietal bone, where, though less marked, it can generally be recognized. In front, this line begins at the zygomatic process of the frontal bone as a curved ridge which runs at first forward and upward on the frontal bone, and then curving backward separates the forehead from the temporal fossa. In front, and behind, the upper border of the arch can be followed into the superior temporal line. The lower border of the arch is more distinct than the upper, which is obscured by the attachment of the temporal fascia. In front of the ear the zygomatic arch can be felt throughout its entire length its posterior end is narrow and is situated a little above the level of the tragus its anterior end is broad and is continued into the zygomatic bone. below and in front of the apex of the mastoid process, the transverse process of the atlas can be distinguished. The anterior border lies immediately behind the concha, and the apex is on a level with the lobule of the auricula. The anterior and posterior borders, the apex, and the external surface of this process are all available for superficial examination. The superior nuchal line can be followed lateralward to the mastoid portion of the temporal bone, from which the mastoid process projects downward and forward behind the ear. Above the superior nuchal lines the vault of the cranium is thinly covered with soft structures, so that the form of this part of the head is almost that of the upper portion of the occipital, the parietal, and the frontal bones. The superior nuchal line runs lateralward from it on either side, while extending downward from it is the median nuchal crest, situated deeply at the bottom of the nuchal furrow. The external occipital protuberance is situated behind, in the middle line, at the junction of the skin of the neck with that of the head. 1193).Various bony surfaces and prominences on the skull can be easily identified by palpation. 1193 Side view of head, showing surface relations of bones.īones (Fig. Surface Anatomy and Surface Markingsį IG.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |