The panels of this image show two more examples of peripheral ganglia. They both have large neuron cell bodies protected by small satellite cells. A second layer of protection of the neuron microenvironment is the flattened outer layer of cells called perineurium. In the right panel, myelinated axons are seen in cross-section in the ganglion and in a few planes of section in a peripheral nerve bundle below the ganglion. The dark nuclei associated with the axons are Schwann cells, which protect the axons and facilitate the transmission of the action potentials.