SOME OBSERVATIONS ON THE FORAMEN MAGNUM OF HUMAN SKULL AND THE SURROUNDINGSSTRUCTURES
- VernacularTitle:关于人颅枕骨大孔及其邻近结构的一些观察
- Author:
Yanzheng YU
;
Shounming TAN
- Publication Type:Journal Article
- From:
Acta Anatomica Sinica
1954;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
1. 400 isolated skulls, 56 skulls from the integral human skeletons, and skulls of10 cadavers (5 adults and 5 juveniles) collected skulls from Shanghai and its vicinity werestudied for the characteristics of foramen magnum and the surrounding structures. 2. The shape of the foramen can be grouped into six types i.e. (1) oval, (2) rhom-boid, (3) ellipsoid, (4) round, (5) mushroom-like, and (6) hexogonal. 3. The percentages of the presence of the posterior condyloid canal were found tobe both sides present, 51%; right side alone 18%; left side alone 18% and both sidesabsent, 13%. The result was almost identical with that of Loh found from the skulls ofWestern China, and not far from that of Wood-Jones found from Northern China. Itis found that the anterior end of the posterior condyloid canal does not always open intothe sigmoid sulcus, but may sometimes lead into the jugular foramen, and in those casesthe vein passing through this canal can not be considered as an emissary vein. 4. Regarding the bony process situated around the anterior margin of the foramenmagnum, it can be classified into three categories according to their positions, i.e. (1)preoccipital spine, i.e. those on the anterior margin of the froman magnum, (2) precondyloidtubercle, i.e. those in front of the occipital tubercle and (3) postclival spine, i.e. thosearound the lower part of the clivus. 5. From the studies of the integral skeletons and the regional dissections, the au-thors found that the appearance of the bony processes may be due to traction and ossifi-cation of end of the ligaments related with the corresponding regions. It is therefore, nota homologous structure of the occipital condyle of the reptiles and birds; it is not athird condyle.
