The Anatomy of the Ganglia

Ganglia is the plural of the word ganglion. Ganglia are clusters of nerve cell bodies found throughout the body. They are part of the peripheral nervous system and carry nerve signals to and from the central nervous system. They are divided into two broad categories, the sensory ganglia and the motor ganglia (which are associated with the autonomic nervous system). 

Anatomy

Ganglia are clusters of nerve cell bodies. Let’s take a look at their structure and location within the body. 

Structure 

There are two types of ganglia in our bodies—sensory and motor. Sensory ganglia are ovoid in shape and contain oval cell bodies with nuclei that form in a circular pattern. 

In the spine, motor ganglia form a long chain from the base of the skull down to the tail end of the spine. Motor ganglia contain irregularly shaped cell bodies.

Location

Sensory ganglia locations include:

• Dorsal roots of spinal nerves
• Roots of some cranial nerves like the trigeminal nerve

One portion of these sensory ganglia connects to the peripheral nervous system. The other is connected to the central nervous system via the brain or spinal cord.

Motor ganglia are part of the autonomic nervous system (ANS). The ANS controls involuntary movements and functions, like your breathing. Motor ganglia locations include:

• The spinal cord: These are called the paravertebral ganglia.
• Internal organs: These include prevertebral ganglia and terminal ganglia.

Function 

Here is more about the function of ganglia in the body. Think of ganglia as the relay stations of the body's nervous system: As one nerve enters a ganglion, another nerve exits it. Ganglia play an essential role in connecting the parts of the peripheral and central nervous systems. 

Motor Function 

Motor ganglia receive information from the central nervous system to regulate and control involuntary movements and functions. Involuntary functions include those of organs such as the heart and lungs. Motor ganglia also send information to the central nervous system from these organs.

Sensory Function 

Sensory ganglia, or dorsal root ganglia, send sensory information to the central nervous system. This information includes touch, smell, taste, sound, and visual stimuli. They also deliver information about body position and sensory feedback relating to organs.

For example, if your stomach hurts, the sensory neurons of the peripheral nervous system are sending a message through the sensory ganglia to your central nervous system that something is not right.

Associated Conditions

Conditions or injuries that may affect the basal ganglia include:

• Head trauma
• Brain tumors
• Infection
• Poisoning 
• Drug overdose
• Stroke
• Multiple sclerosis (MS)

The following conditions are known to affect the basal ganglia in the brain and voluntary movement:

• Parkinson’s disease
• Huntington’s disease
• Dystonia
• Progressive supranuclear palsy

Unsurprisingly, conditions or injuries involving the basal ganglia are extremely serious and often lead to permanent disability or death. 

Damage to other ganglia throughout the body can also cause problems. For example, glaucoma is the result of vision-related ganglia damage. Similarly, an injury to the dorsal root ganglia in the spine, such as spinal vertebrae compression, can cause sensory issues, like tingling in the feet.

Conditions that affect the peripheral nervous system may impact ganglia. Damage to the peripheral nervous system can happen due to:

• Injuries
• Infections
• Genetic abnormalities 
• Genetically inherited disorders
• Tumors
• Problems with blood flow 

Rehabilitation 

Treatment is different depending on the cause of ganglia damage. It also depends on which ganglia have been damaged. 

Some causes of basal ganglia damage, for instance, are reversible and respond well to rehabilitation. Treatments are also available for heavy metal poisoning. Depending on the individual, there may not be any lingering symptoms after treatment. 

However, in the case of Parkinson’s disease, damage to the basal ganglia is part of a progressive illness. Currently, there’s no cure for this disease. Degenerative diseases that affect ganglia in the peripheral nervous system may not be treatable.

People with severe head trauma that impacts the basal ganglia may not recover. If they do, they may end up with a permanent disability.