The preganglionic neuron (LMN) of sympathetic neurons synapses on the postsynaptic neuron in a ___

• A. Sympathetic ganglion
• B. Dorsal root ganglion
• C. Adrenal medulla
• D. Neuromuscular junction

Answer: (A)

Preganglionic sympathetic neurons form a synapse with a postganglionic neuron inside an autonomic (sympathetic) ganglion. This is the relay point where the signal is transmitted from the central nervous system to the second neuron that fibers out to target organs. The adrenal medulla is innervated directly by preganglionic fibers, but it contains chromaffin cells (neuroendocrine cells), not postganglionic neurons, so that isn’t a neuron-to-neuron synapse. The dorsal root ganglion houses sensory cell bodies, not autonomic synapses, and the neuromuscular junction involves somatic motor neurons synapsing onto skeletal muscle, not autonomic targets.