Oxygen

Type: Major Element
Periodic Element: (O)
RDA: Not listed. An adult human at rest inhales 1.8 to 2.4 grams of oxygen per minute.
Importance- To Body:
A major component of both organic (carbon-containing) and inorganic molecules. As a gas it is necessary for the production of cellular energy (ADP). Until the discovery of anaerobic metazoa, oxygen was thought to be a requirement for all complex life. In vertebrates, O₂ diffuses through membranes in the lungs and into red blood cells. Hemoglobin binds O₂, changing color from bluish red to bright red
Distribution- In Body:
65 Approx % Body Mass
The free oxygen partial pressure in the body of a living vertebrate organism is highest in the respiratory system, and decreases along any arterial system, peripheral tissues, and venous system, respectively. Partial pressure is the pressure that oxygen would have if it alone occupied the volume.
Excess Effects:
Prolonged breathing of an air mixture with an O₂ partial pressure more than 60 kPa can eventually lead to permanent pulmonary fibrosis. Exposure to a O₂ partial pressures greater than 160 kPa (about 1.6 atm) may lead to convulsions (normally fatal for divers). Acute oxygen toxicity (causing seizures, its most feared effect for divers) can occur by breathing an air mixture with 21% O₂ at 66 m (217 ft) or more of depth; the same thing can occur by breathing 100% O₂ at only 6m (20 ft)
Deficiency Effects:
Hypoxia. Total atmospheric pressure decreases as altitude increases, causing a lower partial pressure of oxygen which is defined as hypobaric hypoxia. Oxygen remains at 20.9% of the total gas mixture, differing from hypoxic hypoxia, where the percentage of oxygen in the air (or blood) is decreased.
Sources:
Ambient Air
Sources Environmental/Geographic:
while some estimates are lower, suggesting oceans produce ~45% of Earth’s atmospheric oxygen each year.
Supplemental information: