Final answer:
The autonomic nervous system consists of the sympathetic and parasympathetic divisions, which have opposing effects on the body. The sympathetic division triggers the fight or flight response, while the parasympathetic division promotes rest and digest activities, maintaining the body's homeostasis.
Step-by-step explanation:
The autonomic nervous system is a component of the peripheral nervous system that regulates involuntary physiological processes. It comprises two main pathways: the sympathetic and parasympathetic divisions. These two divisions generally have opposite effects on the same organs. The sympathetic nervous system is responsible for the "fight or flight" response, preparing the body for action by increasing heart rate, among other effects. On the other hand, the parasympathetic nervous system is often referred to as the "rest and digest" system because it conserves energy as it slows the heart rate, facilitates digestion, and promotes relaxation of the body.
Comparison of the Sympathetic and Parasympathetic Divisions
- The sympathetic division activates the fight or flight response.
- The parasympathetic division activates the rest and digest response.
An example of these divisions at work is in the regulation of the heart: sympathetic activity increases heart rate, while parasympathetic activity decreases it. This dual innervation helps maintain homeostasis within the body. In stressful situations, like encountering a dangerous animal, the sympathetic division predominates, whereas during relaxing times, the parasympathetic division takes precedence.