A new method of demonstrating the topographical anatomy of the adult human skull / by Sydney R. Scott.

  • Scott, Sydney Richard, 1875-1966.
Date:
[1906?]
Catalogue details

Licence: In copyright

Credit: A new method of demonstrating the topographical anatomy of the adult human skull / by Sydney R. Scott. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    6/22 (page 172)
    1. THE NORMA BASILARIS. To illustrate the norma basilaris, two triangular figures are constructed as follows (see fig. 1):—1 C N S and C N S are two right-angled isosceles triangles, the side C N being common to both triangles and equal to C S and C S. Then the points N, S, and S correspond to the relative positions of the post-nasal spine and the two stylo-mastoid foramina respectively, while C corresponds to a point which would be just behind the basion. C is the central point of the base of the skull, and on an average is within the foramen magnum and half a centimetre from the anterior margin of that foramen. For practical purposes we may remember that the basion is just in front of the central point. Fig. 1.—N, the post-nasal spine ; S, S, the stylo-mastoid foramina ; C, the “central point” (in the average adult skull half a centimetre behind the basion). The line C N is then prolonged to A, making N A equal to C N: A is joined to S and S respectively, thus another isosceles triangle, S A S, is produced (fig. 2). The point A corresponds to the position of the anterior margin of the anterior palatine fossa. The sides A S and A S represent the well-known guide-lines to the following foramina etc.:—The anterior palatine fossa, the posterior palatine foramen, the pterygoid fossa, the foramen ovale, the foramen spinosum, the vaginal process of the tympanic plate, the stylo-mastoid foramen. The posterior palatine foramen is situated on the line A S (we may call this the palato-styloid line), two-fifths the distance from the point A. (For the uniformity of this position, see charts 10 and 11.) Midway between the posterior palatine foramen and the stylo-mastoid 1 The illustrations accompanying this paper have been produced by following the description given in the text, and without reference to any skull or any other illustration. As mentioned in the text, it has been my purpose to devise a method whereby anyone unskilled in perspective drawing can delineate the essential topographical features of the skull merely by applying accurate anatomical knowledge.