Final answer:
The nervous system not only detects external signals via receptors but also monitors internal signals, ensuring dynamic homeostasis through the coordination of other systems like the endocrine system.
Step-by-step explanation:
The statement that the nervous system keeps us in touch with our external environment only is false. The nervous system has a complex role that includes detecting both external and internal signals. It is responsible for transmitting and integrating information, and then producing responses. For instance, the nervous system monitors the external environment through nerve receptors in the skin, allowing us to sense temperature, pressure, and pain. However, it also tracks internal conditions and processes, such as monitoring carbon dioxide levels in the blood, or the stretching of the stomach walls after eating.
To ensure proper functioning of the body, the nervous system works alongside other systems, like the endocrine system, which is also activated by chemical messengers. This coordination supports dynamic homeostasis, helping to maintain a stable internal environment in response to changes both inside and outside the body.