The visceral efferent (also known as the autonomic nervous system) typically consists of a two-neuron chain to reach the target tissue. This two-neuron pathway is a characteristic feature of the autonomic nervous system. Here's how it works:
1. The preganglionic neuron: This is the first neuron in the chain. It originates in the central nervous system (CNS) and extends to a ganglion (a cluster of nerve cell bodies) located outside the CNS. In the sympathetic division, these preganglionic neurons are relatively short, while in the parasympathetic division, they are longer.
2. The postganglionic neuron: This is the second neuron in the chain. It extends from the ganglion to the target tissue, such as smooth muscle, cardiac muscle, or glands. The postganglionic neuron is responsible for transmitting the signal to the specific organ or tissue where it elicits the desired response.
So, in summary, the visceral efferent pathway consists of two neurons (preganglionic and postganglionic) to reach the target tissue.