Postganglionic fiber

Postganglionic fiber is a type of neuron that is part of the autonomic nervous system. It is the second neuron in the two-neuron chain that comprises the autonomic nervous system. The first neuron in this chain is the preganglionic neuron.

Anatomy

The postganglionic fiber originates in the autonomic ganglion, where it is connected to the preganglionic neuron. The postganglionic fiber then extends to the target organ or tissue, where it releases neurotransmitters to stimulate or inhibit activity.

Function

The primary function of the postganglionic fiber is to transmit signals from the autonomic ganglion to the target organ or tissue. This is a critical component of the body's ability to maintain homeostasis.

In the sympathetic nervous system, postganglionic fibers typically release the neurotransmitter norepinephrine, which stimulates the target organ or tissue. In the parasympathetic nervous system, postganglionic fibers typically release the neurotransmitter acetylcholine, which inhibits the target organ or tissue.

Clinical significance

Abnormalities in postganglionic fibers can lead to a variety of medical conditions. For example, damage to postganglionic fibers in the sympathetic nervous system can result in Horner's syndrome, a condition characterized by drooping eyelids, constricted pupils, and lack of sweating on one side of the face.

See also

• Preganglionic fiber
• Autonomic nervous system
• Sympathetic nervous system
• Parasympathetic nervous system