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Sagittal section through the upper
cervical spine of an elderly man who had not had neck symptoms. The
section is carried through the left lateral mass and the occipital
condyle. The dark venous channels in the occipital bone are the
hypoglossal canal on the left and a small portion of the sigmoid
sinus to the right. The convex occipital condyle has a normal
cartilage and articulates with the concave and moderately
degenerated articular surface of the atlas (C1) which also displays
subchondral sclerosis. The occipito–atlantal joint has a
ball–and–socket shape that permits flexion–extension and lateral
bending. By contrast, the atlanto–axial joint (C1–C2) facilitates
axial rotation (around the axis of the odontoid process) by
translation (sliding) of the convex joint surfaces. Meniscoid
synovial folds project into the C1–C2 joint space anteriorly and
posteriorly. The spaces above and below the arch of the atlas are
occupied by wide venous sinuses. Between the occiput and C1 the
vertebral artery (red) and the small C1 nerve behind the artery are
completely surrounded by the venous sinusoid, between the C1 lamina
and the pars interarticularis of C2 a venous cavern surrounds the
large C2 root ganglion (yellow). |
©2000 Wolfgang Rauschning, M.D., Ph.D.
Professor of Clinical Anatomy
Academic
University Hospital
Department of Orthopaedic Surgery
Uppsala, Sweden
Reproduction without permission is prohibited
http://www.akademiska.se/
