How does the respiratory system help maintain homeostasis in the body?

Respiratory system helps maintain the body's homeostasis by providing oxygen needed for metabolism, eliminating carbon dioxide and helping to maintain acid-base balance.

Explanation:

The respiratory system is in charge of the breathing process, which includes the intake of oxygen-charged air (O₂) with inspiration and the elimination of carbon dioxide (CO₂) with expiration.

Ways the respiratory system helps maintain homeostasis are:

Oxygen supply

Cells need O₂ to be able to perform the metabolic processes of energy production.

By breathing in ambient air, O₂ enters the lungs and eventually passes into the pulmonary alveoli. In the alveoli the process of diffusion of O₂ into the pulmonary capillary occurs, and then it is carried by the erythrocytes —via blood circulation— to all tissues.

Elimination of carbon dioxide

CO₂ is a product of metabolism, which must be eliminated because it is potentially toxic. This gas is transported by the erythrocytes to the pulmonary capillary, from where it will pass to the alveolus by diffusion, to be eliminated with the expiration. The entire process of alveolar O₂ input and O₂ output is known as gas exchange.

Regulation of the acid-base balance

CO₂ produced by the metabolism is slightly acidic and its increase is capable of producing respiratory acidosis. On the other hand, O₂ has a tendency to alkalinity, and its accumulation -by hyperventilation- produces alkalosis.

When CO₂  is accumulated, or in other circumstances where there is acidosis in the body, a compensatory mechanism is activated at the respiratory level to introduce a greater amount of O₂ , in order to try to achieve acid-base balance and homeostasis.

the fossil record provides evidence of a common ancestor to many species.