POSTGANGLIONIC NEURONS Meaning and
Definition
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Postganglionic neurons refer to the type of neurons that are found in the autonomic nervous system (ANS), specifically in the peripheral nervous system. These neurons are responsible for transmitting signals from ganglia, which are clusters of nerve cell bodies, to various peripheral target tissues such as smooth muscles, glands, and cardiac muscle.
After receiving information from preganglionic neurons, which originate from the central nervous system, postganglionic neurons relay this information to their respective target organs or tissues. In the ANS, there are two subcategories of postganglionic neurons: sympathetic and parasympathetic.
Sympathetic postganglionic neurons are responsible for activating the "fight or flight" response in the body. They release the neurotransmitter norepinephrine (noradrenaline), which affects organs such as the heart, blood vessels, and sweat glands. Activation of these neurons prepares the body for action, increasing heart rate, constricting blood vessels, and inducing sweating.
On the other hand, parasympathetic postganglionic neurons are involved in the relaxation response and restoration of bodily activities to normal levels after stress or exertion. These neurons release the neurotransmitter acetylcholine, which slows heart rate, dilates blood vessels, and promotes digestion and other restorative processes.
Overall, the function of postganglionic neurons is to transmit signals from ganglia to target tissues, allowing for the regulation and coordination of involuntary physiological responses in the body.
Etymology of POSTGANGLIONIC NEURONS
The word "postganglionic" is formed by combining two terms: "post" and "ganglionic".
"Post" is a prefix derived from the Latin word "post", meaning "after" or "behind".
"Ganglionic" is an adjective form of the noun "ganglion", which comes from the Greek word "ganglion", meaning "knot" or "swelling". In biological terms, a ganglion refers to a cluster or group of nerve cells.
Therefore, "postganglionic" refers to something "after or behind a ganglion".
The term "neurons" is derived from the Greek word "neuron", which means "nerve". Neurons are specialized cells that transmit electrical signals and are fundamental to the functioning of the nervous system.
