Oxygen and the Body
Oxygen is a colorless and odorless gas that makes up about 20% of the atmosphere. Oxygen in a human body is absorbed into the blood through the lungs. Our body needs a continuous oxygen supply to its cells in order for the carbohydrates, proteins, and fats to be oxidized (burned) to release energy. Oxygen is also essential for respiration. Oxygen is used for the chemical reactions that occur in the cells of the body.
Oxygen is highly reactive towards organic molecules.
Body cells are built from the lipids (fat-like substances), which easily yield to oxidation. From one side, oxygen is vital for sustaining life in our body. But from the other side, the body must protect its cells from the reactive oxygen forms. In the body there exists a multilevel protection from the reactive oxygen forms.
All body cells go through a process of the development and separation from the mother cell, aging, and finally dying. Each body cell has the programmed cell death receptors, which react to the "its time to die" signal. The cells are constantly developed; they die and are substituted by new cells. The reactive oxygen forms participate in this process as well.
High oxygen reactivity also serves the body in dealing with infections, regulation of proliferation (rapid growth and reproduction of cells) and apoptosis (programmed cellular death). Oxygen participates in diverse pathologic processes: inflammation (reaction of tissues to injury or disease resulting in swelling, redness, heat, and pain), fever (a rise in the body temperature), hyperemia (excess of blood in some part of the body) etc.
|
