Answer
The nervous and skeletomuscular systems help maintain homostasis by regulating respiration.
Explanation:
The brain stem, consisting of the pons and medulla, represent the main respiratory center. According to Wikipedia, "an increased level of carbon dioxide in the blood, or a decreased level of oxygen, will result in a deeper breathing pattern and increased respiratory rate to bring the blood gases back to equilibrium."
This is an example of a homostastic response controlled by both of the organ systems referenced above.
Source: https://en.wikipedia.org/wiki/Homeostasis
