Anatomy and Cell Biology 3319 Lecture Notes - Lecture 3: Ramus Communicans, Dorsal Root Ganglion, Anterior Ramus Of Spinal Nerve
15 Dec 2017
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31 pairs of spinal nerves: each contains thousands of nerve fibers, attached to spinal cord. Note: 8 pairs of cervical nerves, only 7 cervical vertebrae: c1 lies superior to the first vertebra, whereas c8 exits inferior to the seventh cervical vertebra. Leaves 6 nerves in between: every spinal nerve exits inferior to the vertebra of the same number. Each spinal nerve connects to spinal cord by a dorsal root and a ventral root: each root forms rootlets that attach along the whole length of the spinal cord segment. Dorsal root contains axonal processes of sensory neurons arising from cell bodies in the dorsal root ganglion. Ventral root contains axonal processes of motor neurons whose cell bodies are located in the ventral gray column of the spinal cord. Spinal nerve lies at junction of the dorsal and ventral roots: lateral to dorsal root ganglion.
