Dorsal Root Ganglia

Definition

A collection of cell bodies for sensory peripheral nerves that are attached to the dorsal nerve roots. The term “ganglion” refers to a collection of cell bodies outside the central nervous system. Each neuron is associated with a cell body. In the majority of cases an axon exits the cell body at one point (axon hillock) and the dendritic processes are attached at one (bipolar) or more (multipolar) sites on the same cell body. The spinal sensory nerves have a different arrangement. These are unipolar neurons. There is a single short extension off the axonal process that goes to the cell body. Just before the dorsal nerve roots (which represent a collection of individual sensory nerve fibers) enter the spinal cord their axons give off these unipolar branches to their individual cell bodies. Thus, each dorsal nerve root has a very visible bulb-like enlargement just outside the cord which represents a collection of these cell bodies which are known as the dorsal root ganglia. A...