The nervous system and respiratory system depend on each other for proper physiological function. The nervous system acts to regulate and sense needed changes in respiratory rate, while the respiratory system is responsible for providing much-needed feedback regarding gas regulation. They are both needed, of course, for the overall ability to survive.
Physiology is the study of the systems of the body. For the sake of convenience, physiological systems are sometimes examined individually; although in reality, each system largely depends on the others. The offset of one system may imbalance the others, often leading to disease. The nervous and respiratory systems are no exception to this relationship dependence characteristic of physiological systems.
The respiratory system functions to achieve gas exchange. Gas exchange not only allows for needed nutrients to enter the bloodstream, but it also enables the release of chemicals and metabolic by-products that could otherwise tarnish the body's health. This seemingly simple process is actually incredibly complex, involving many organs, structures, and muscles to accomplish an end goal of healthy gas exchange. It would be too easy if gas exchange were static, so of course, this process is further complicated by a dynamic need of the body for exchange. A person at rest, for example, needs less oxygen than an individual exercising.
The body relies on the interaction of the nervous system and respiratory system to accommodate its dynamic physiological needs. The nervous system plays a role in sensing a need for change and initiating appropriate action. One way to understand the interaction of the nervous system and respiratory system is to run through an example of change and response.
A person who transitions from a walking to running state experiences a change in bodily system functions. While walking, this person is probably in a homeostatic state. Once people begin to move rapidly, their muscles and cardiovascular systems are stressed to accommodate an elevated state. This elevated state needs more oxygen and nutrients to sustain itself and relies on the respiratory system to acquire more oxygen.
The nervous system acts to sense this change and send information about the exact change to the brain and spinal cord. The brain and spinal cord process this information and use the nervous system as an informational pathway to get messages back to the body. These messages could say to slow down or speed up, depending on the situation. This is the manner in which the nervous system and respiratory system are related.