Parasympathetic ganglia

Parasympathetic ganglia are integral components of the autonomic nervous system, specifically the parasympathetic nervous system. They are clusters of neuron cell bodies that relay signals from the brain to various parts of the body to regulate involuntary bodily functions such as heart rate, digestion, and salivation.

Structure

Parasympathetic ganglia are located close to or within the organs they innervate. This is in contrast to the sympathetic ganglia, which are located in a chain along the spinal cord. The parasympathetic ganglia include the ciliary ganglion, pterygopalatine ganglion, otic ganglion, and submandibular ganglion, among others.

Function

The primary function of the parasympathetic ganglia is to transmit signals from the brain to various parts of the body to regulate involuntary bodily functions. These signals are transmitted through nerve fibers that connect the ganglia to the organs they innervate. The parasympathetic nervous system is often referred to as the "rest and digest" system, as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.

Clinical significance

Dysfunction of the parasympathetic ganglia can lead to a variety of medical conditions. For example, damage to the ciliary ganglion can result in ophthalmoplegia, a condition characterized by paralysis or weakness of the eye muscles. Similarly, damage to the otic ganglion can lead to xerostomia, or dry mouth.

See also

• Autonomic ganglion
• Sympathetic ganglion
• Enteric nervous system