Question

Are there any parts of the human body that get oxygen directly from the air and not from the blood? Are there nuclear reactions going on in our bodies?​

Answer 1

The cornea is the only part of a human body that has no blood supply; it gets oxygen directly through the air. The cornea is the fastest healing tissue in the human body, thus, most corneal abrasions will heal within 24-36 hours.

Nuclear reactions do indeed occur in the human body, but the body does not use them.