Ganglia are collections of cell bodies outside the CNS, for sensory or autonomic nerves.

• Outside the spinal cord on slide 9 and 6T, locate and examine a spinal or dorsal root ganglion (Fig. 9-29a,b). (Another example of a larger dorsal root ganglion is sectioned on slide 137.)
• Identify the large neurons (which are sensory),
• The glial satellite cells surrounding each neuron (Fig. 9-29c,d, and
• The CT covering the entire ganglion.

What is the difference between the satellite cells of ganglia and the satellite cells you learned about in muscle?

Clinical note:  The herpes zoster virus, acquired during childhood chicken pox, can remain dormant in neurons of sensory ganglia and can be reactivated in older individuals, migrating along axons to the skin and producing blisters and a painful rash known as shingles. Although skin symptoms usually heal within weeks, the pain (post-herpetic neuralgia) may persist for many months.

Examine an sympathetic ganglion (Fig. 9-29c) on slide 135 and identify the same structures just found in the sensory ganglion.

• Smaller parasympathetic ganglia will be found in the wall of the small intestine (slide 37), esophagus (slide 43), and in some areas of loose CT (slide 45).

What are similarities and differences between an autonomic ganglion and a spinal ganglion?

Now let's look at peripheral nerves.