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Coronal section through the pedicles of
L2, L3, and L4. This section through the mid–pedicle level shows the
serpentiginous course of the nerve roots in a thecal sac of normal
width. The shallow (axillary) pouches of the root sleeves lie
immediately below the pedicles where the roots snugly follow the
pedicles. The cancellous and cortical bone and the cross–sectional
shape of the pedicles vary within wide ranges. At L2–L3 large veins
lie lateral to the dura, at L3–L4 the dura is bordered by fat
interspersed with smaller veins. At L2–L3 the section is closer to
the base of the pedicles and therefore shows the ventral internal
venous plexus whereas at L3–L4 the posterior, less vascularized
portion of the foramen is displayed. At two levels the entire course
of the "roots" can be followed. This root–complex consists of the
still intrathecal roots, the root sheath (or root sleeve), the
dorsal root ganglion and the ventral root, and the postganglionic
lumbar nerve. The long, cylindrical lumbar ganglia take a steep and
obliquely–inferiorly directed course towards the upper lateral comer
of the infrajacent pedicle. Lateral to the ganglion and close to the
inferior–lateral margin of the pedicle the segmental arteries are
located. The lumbar nerve curves around the lateral aspect of the
pedicle below, firmly held by the deep portions of the iliopsoas
muscle. |
©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/
