What gases are regulated? How?

The body is constantly working to regulate the amount of oxygen (O₂) and carbon dioxide (CO₂) in the blood stream. It is vital that the body responds to any changes in optimum levels of these gases quickly and effectively.

The primary function of O₂ is to provide our body with energy. It all happens within the cells, in little organelles called mitochondria which are real energy generators: they use oxygen to transform nutrients from the digestive process into energy that can be used directly by the cell (ATP) in a process called cellular respiration.

Gas exchange helps maintain homeostasis by supplying cells with O₂, carrying away CO₂ waste, and maintaining proper pH of the blood.

Breathing (respiration) occurs due to repeated contractions and relaxation of the intercostal muscles of the rib cage and a large muscle called the diaphragm. The rate of breathing is regulated by the brain stem. The maintenance of consistent levels of O₂ and CO₂ in the blood is vital for homeostasis and is maintained by peripheral chemoreceptors capable of detecting changes in the partial pressures of oxygen and carbon dioxide (PO₂/PCO₂).

Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. Inhaled O₂ moves from the alveoli to the blood in the capillaries, and CO₂ moves from the blood in the capillaries to the air in the alveoli.

How does illness, infection and trauma impact on this?

Illnesses, infections, and severe trauma can cause an alteration in the body’s metabolism, resulting in excess CO₂ production. If your breathing can’t catch up with your need to exhale CO₂ from your body, you can develop an elevated blood CO₂ level which can be dangerous.