POSTGANGLIONIC NEURON Meaning and
Definition
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A postganglionic neuron is a type of nerve cell found in the autonomic nervous system (ANS), which is responsible for regulating involuntary bodily functions. It serves as the second neuron in the two-neuron pathway of the autonomic nervous system.
The ANS is divided into two major components: the sympathetic and parasympathetic nervous systems. The postganglionic neuron belongs to either of these systems and receives signals from the preganglionic neuron, which is the first neuron in the pathway.
Specifically, in the sympathetic division, postganglionic neurons are located in ganglia that run parallel to the spinal cord. They transmit nerve impulses from the ganglia to target tissues such as blood vessels, sweat glands, and other organs, in order to activate the "fight-or-flight" response. On the other hand, in the parasympathetic division, postganglionic neurons are situated near or within the target organs and regulate the body's "rest-and-digest" response, promoting relaxation and normal body functions.
The term "postganglionic" refers to the location of these neurons after they pass through a ganglion, which is a cluster of nerve cell bodies. These neurons extend their axons to reach their target tissues, where they release neurotransmitters to transmit signals and regulate functions such as heart rate, digestion, respiration, and pupil constriction.
Overall, postganglionic neurons play a crucial role in the autonomic nervous system by relaying nerve signals from the preganglionic neurons to target organs to maintain the balance and regulation of various bodily functions.
Etymology of POSTGANGLIONIC NEURON
The word "postganglionic" is derived from two components: "post-" and "ganglionic".
1. "Post-" is a prefix in English, derived from the Latin word "post" meaning "after" or "behind". In the context of the nervous system, it refers to structures that are located after or distal to a certain point.
2. "Ganglionic" is an adjective derived from the noun "ganglion". "Ganglion" comes from the Greek word "ganglion" meaning "knot" or "swelling". In the nervous system, a ganglion refers to a collection of nerve cell bodies located outside the central nervous system (brain and spinal cord).
Therefore, when combined, "postganglionic" refers to an anatomical location after or distal to a ganglion.
