GUIDE
Back and Spinal Cord: Spinal Cord
Spinal Cord
[Plate 157, Spinal Cord and Ventral Rami In Situ]Originates at the inferior end of the medulla oblongata and terminates as conus medullaris
Is approximately 42 to 45 cm long from the foramen magnum to L2 (variable from T12-L3)
Is connected from the conus medullaris to the coccyx by the filum terminale (a strand of connective tissue that connects exits from the dural
sac and passes through the sacral hiatus)
Has two regional enlargements
Cervical-origin of the brachial plexus innervating the upper limb
Lumbosacral-origin of the lumbar and sacral plexuses innervating the lower limb
Has the following features in cross section
Dorsal median sulcus and ventral median fissure that divide cord into symmetrical halves
Central canal carrying cerebrospinal fluid (CSF)
White matter surrounding an H-shaped core of grey matter (ventral and dorsal horns)Structure of Spinal Nerves