Final answer:
The sympathetic and parasympathetic branches of the autonomic nervous system have major anatomical differences. The sympathetic branch has its preganglionic neurons located in the thoracolumbar spinal cord, while the parasympathetic branch has its preganglionic neurons located in nuclei of the brain stem and the lateral horn of the sacral spinal cord. Additionally, the sympathetic branch has a broad influence throughout the body due to its widely diverging projections, while the parasympathetic branch has a more localized effect.
Step-by-step explanation:
The sympathetic and parasympathetic branches are two subdivisions of the autonomic nervous system that control the body's involuntary functions. The main anatomical differences between these branches include:
- The sympathetic branch has its preganglionic neurons located in the thoracolumbar spinal cord, while the parasympathetic branch has its preganglionic neurons located in nuclei of the brain stem and the lateral horn of the sacral spinal cord.
- The sympathetic branch has a broad influence throughout the body due to its widely diverging projections, while the parasympathetic branch has a more localized effect.
- The sympathetic branch releases norepinephrine as its neurotransmitter at the postganglionic synapses, while the parasympathetic branch releases acetylcholine.
These anatomical differences result in different physiological responses and functions of the two branches.