What are ganglia in the nervous system?
Ganglia are oval shaped structures which contain cell bodies of neuron, glial cells and connective tissue.
Ganglia are part of peripheral nervous system. They work as relay station for nerve signals. One nerve enters and another nerve exits from each ganglion (singular: ganglion plural: ganglia).
There are 2 types of ganglia : Sensory & Autonomic.
Sensory ganglia receive signal from periphery and send them to brain.
In case of Autonomic ganglia the nerve signal travel in opposite direction.
The picture of a sensory ganglia : Dorsal Root Ganglion
Diagram of autonomic nervous system. See the autonomic ganglia : prevertebral and paravertebral.