Variant inferior root of ansa cervicalis / Variación de la raíz inferior del asa cervical

Ansa cervicalis is a loop of nerves found in the anterior wall of the carotid sheath in the carotid triangle of neck innervating infrahyoid muscles. Its superior root has fibres from the first cervical nerve that leaves the hypoglossal nerve and joins the inferior root formed by the branches from the second and third cervical nerves. The two roots join to form ansa cervicalis. The ansa cervicalis nerve formation is relatively complex, as its course and location along the great vessels of the neck vary. In the present case on the left side of an adult male cadaver the inferior root was absent and the contributions from C2 and C3 were joining independently with the superior root of ansa to form ansa cervicalis. However no such variation was found in the ansa cervicalis formation on the right side.

El asa cervical es un loop de nervios que se encuentra en la pared anterior de la vaina carotídea, en el triángulo carotídeo del cuello, que inerva los músculos infrahioideos. Su raíz superior tiene fibras del primer nervio cervical que sale del nervio hipogloso y se une a la raíz inferior formada por las ramas de los nervios cervicales segundo y tercero. Las dos raíces se unen para formar el asa cervical. La formación del asa cervical del nervio es relativamente compleja, ya que su curso y ubicación varía a lo largo de los grandes vasos del cuello. En el lado izquierdo del cuello de un cadáver adulto de sexo masculino, la raíz inferior del asa cervical estaba ausente y las contribuciones de los ramos de C2 y C3 se unieron, de forma independiente, con la raíz superior del asa y así formar el loop.

Gender differences in the Egyptians by osteometric measurements of the second cervical vertebrae [C2] with scanning electron microscopic examination of the vertebral body trabeclae

This study has been performed in order to define standards to determine the sex of the Egyptian remains. Osteometric information was obtained from dens, facets and vertebral canal of the second cervical vertebrae. Ninety-two normal second cervical vertebrae were taken from 64 male and 28 female Egyptian cadavers with their age ranged from 24 up to 68 years. Nine measurements [dens height, anterior and posterior body heights, maximum and minimum anteroposterior and transverse dens diameters, anterior facet width and height of dens] were estimated for the dens. Also, five measurements of the facets [right and left superior articular facet widths and lengths and inter-facet width] and two for the vertebral canal [antero-posterior and transverse diameters] for each second cervical vertebra were estimated and statistically analyzed. Small cubes [0.5cm3] from the body of second cervical vertebrae were cut and prepared for the examination of the vertebral trabecvilar bones by scanning electron microscope. The present study revealed significant differences between males and females as regards the osteometric measurements of the dens, facets and vertebral canal of the second cervical vertebrae. Multivariant discriminant analysis showed that a discriminant function consisting often variables could be used to identify the sex, The variables were right superior articular facet length, anterior facet width of dens, minimum transverse dens diameter, minimum antero-posterior dens diameter, dens height, anterior facet height of dens, maximum antero-posterior and transverse diameters of the vertebral canal, maximum antero-posterior dens diameter and inter-facet width. 100% of the sensitivity and specificity of the cut off point of the studied variables were observed in maximum antero-posterior diameter of the vertebral canal, right and left superior articular facet lengths, anterior facet width and height of the dens. On the other hand, the lowest percentage of sensitivity and specificity [59.4% and 57.1% respectively] of the cut off point was noticed in anterior body height. Moreover, in this study scanning electron microscope revealed gender difference in the width of the vertebral body trabeculae and in the numbers of the bone marrow spaces. So, these results can help in identification of Egyptian's sex from dens, facets and vertebral canal of the second cervical vertebrae as well as the vertebral trabeculae when no other human remains are available. Also, the present study suggests that this anthropometric database can be used in mathematical modeling of the vertebral column and identification of Egyptian's sex