Oxygenated

The Earth possesses a thick, oxygenated atmosphere.

Then about 2.3 to 2.5 billion years ago, during the Proterozoic Eon, blue-green algae called cyanobacteria, living in Earth’s shallow oceans, began emitting enough oxygen through photosynthesis to create the permanently oxygenated atmosphere that keeps us alive today.

The left ventricle of the heart pumps oxygenated blood to the entire body through the aorta.