Skip main navigation

What gases are regulated? How?

The body is constantly working to regulate the amount of oxygen and carbon dioxide in the blood stream. Read about gas exchange in this article.
mango swamp (illustrating oxygen)

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.

This article is from the free online

Finding the Body’s Balance: Understanding Homeostasis

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education