Final answer:
The autonomic nervous system's efferent pathways consist of a two-neuron chain: preganglionic and postganglionic neurons. These neurons connect the CNS to effector organs in the sympathetic and parasympathetic systems, which mediate responses like 'fight or flight' and 'rest and digest' respectively.
Step-by-step explanation:
The efferent pathways of the autonomic nervous system consist of a two-neuron chain: a preganglionic neuron and a postganglionic neuron. The preganglionic neuron originates in the central nervous system (CNS) and travels to a ganglion in the peripheral nervous system (PNS). There, it synapses with a postganglionic neuron, which then extends to an effector organ, such as a muscle or gland.
The autonomic nervous system is divided into the sympathetic and parasympathetic systems, which have opposing effects. The sympathetic system is responsible for the "fight or flight" response, while the parasympathetic system supports "rest and digest" activities. The efferent branch of the visceral reflex arc starts with a central neuron projecting along a preganglionic fiber, which then synapses on a ganglionic neuron. This ganglionic neuron subsequently projects to the target effector, completing the efferent pathway.