Chapter 18, Problem 1WYL

How are motor neurons organizationally different in the ANS versus the SNS?

Summary Introduction

To determine:

The difference between the organization of motor neurons in the ANS and the SNS.

Introduction:

The autonomic nervous system (ANS) is also known as autonomic motor or visceral motor system. The somatic nervous system (SNS) includes processes that are controlled consciously.

Explanation of Solution

The differences between the organization of motor neurons in the ANS and SNS are as follows:

No.	Characteristics	ANS	SNS
1.	Number of motor neuron	A chain of two motor neurons extends from the CNS (central nervous system) to innervate smooth muscle, cardiac muscle, and glands in ANS.	A single motor neuron extends from CNS to skeletal muscle fibers in SNS.
2.	Ganglia associated with motor neurons	Autonomic ganglia, terminal, intramural, and prevertebral ganglia are associated with motor neuron.	None of the ganglia is associated with the motor neurons.
3.	Neurotransmitter released	Preganglionic axons release ACh neurotransmitter and postganglionic axons release either ACh or norepinephrine (NE).	Motor neuron releases acetylcholine (ACh) neurotransmitter from its synaptic knobs.