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How do autonomic motor ganglia relay signals to internal organs?
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human nervous system
The conduction of electrochemical stimuli from sensory receptors in the human nervous system occurs via organized groups of specialized cells, consisting largely of neurons, various neural support cells, and tracts of nerve fibers.
Autonomic motor ganglia relay signals to internal organs through a two-neuron chain system.1
- Preganglionic Neurons: These originate in the brainstem or spinal cord and send fibers to the autonomic ganglia.21
- Synaptic Transmission: Within the ganglia, preganglionic fibers release neurotransmitters—typically acetylcholine—which bind to receptors on the multipolar cell bodies of postganglionic neurons.23
- Postganglionic Neurons: Once activated, these neurons send their own axonal processes directly to the target visceral structures, such as cardiac muscle, smooth muscle, or glands.21
The location of these ganglia varies by division: sympathetic ganglia are often found in sympathetic trunks (paravertebral) or near target organs (prevertebral), while parasympathetic ganglia are typically located on the surfaces of or within the walls of the target organs themselves. Upon reaching the final destination, these fibers release neurotransmitters across a junction to initiate physiological responses in the effector cells.213