How is hydrogen carried in the blood?

Hydrogen is primarily carried in the blood in the form of carbonic acid or fixed acids. This occurs through the buffering system of the blood, particularly involving carbon dioxide and bicarbonate. When carbon dioxide is produced by the tissues, it diffuses into red blood cells, where it is converted to carbonic acid by the enzyme carbonic anhydrase. This carbonic acid can dissociate into hydrogen ions and bicarbonate. The bicarbonate can travel in the plasma, while the hydrogen ions play a crucial role in maintaining the acid-base balance of the blood.

Additionally, while there are mechanisms for transporting ions, hydrogen does not primarily exist in its elemental form or as free ions in circulation, as the body maintains a tight regulation of pH. Fixed acids can also contribute to the overall acid load in the blood but are less significant than the mechanisms involving bicarbonate and carbonic acid. This understanding is vital for managing patients in neonatal intensive care, where acid-base balance is crucial for the health of newborns.