In the human body, every spinal nerve has essentially the same construction
By learning the anatomy of one spinal nerve, you can understand the anatomy of all spinal nerves.
Like a tree, a typical spinal nerve has roots, a trunk, and branches (rami).
Label 1 Roots
Coming off of the posterior and anterior sides of the spinal cord are the posterior (dorsal) and anterior (ventral) roots of the spinal nerve.
An enlargement on the posterior root is the posterior root ganglion.
A ganglion is a collection of neuron cell bodies, together, outside the CNS.
Label 2 Trunk
Laterally, the posterior and anterior roots of the spinal nerve join to form the spinal nerve trunk.
The spinal nerve trunk of each spinal nerve is located in the appropriate intervertebral foramen of the vertebral column. (An intervertebral foramen is a passage formed on either side of the junction between two vertebrae.)
Label 3 Branches
Where the spinal nerve trunk emerges laterally from the intervertebral foramen, the trunk divides into two major branches.
These branches are called the anterior (ventral) and posterior (dorsal) primary rami (ramus, singular).
The posterior primary rami go to the back.
The anterior primary rami go to the sides and front of the body, and to the upper and lower members.