hapnikuvaru

Hapnikuvaru (oxygen reserve) is a term used in physiology and related disciplines to describe the amount of oxygen that is readily available for use by cells when normal oxygen intake is disrupted. It encompasses the stores that can be drawn upon during brief interruptions in oxygen supply and the capacity to maintain cellular respiration under stress.

In humans and other air-breathing animals, the body’s oxygen reserve is stored mainly in hemoglobin within red blood cells, with a smaller portion dissolved in plasma. The muscles also hold a reserve of oxygen in the form of myoglobin, which helps sustain muscle activity during brief pauses in blood flow. In practice, the oxygen bound to hemoglobin constitutes the major share of usable oxygen, while dissolved oxygen provides a small, immediate source.

Oxygen reserves are finite and must be replenished by respiration. The size of the reserve depends on factors such as blood hemoglobin concentration, oxygen saturation, lung function, and physical activity level. Clinically, oxygen reserve is evaluated using measurements like arterial partial pressure of oxygen (PaO2) and oxygen saturation (SpO2). Oxygen therapy or supplemental oxygen increases the amount of dissolved oxygen in plasma and the oxygen carried by hemoglobin, effectively expanding hapnikuvaru during illness or hypoxemic conditions.

Outside physiology, hapnikuvaru also refers to stored oxygen in tanks or other systems used in medicine, diving, aviation and spaceflight. In aquatic environments, dissolved oxygen is the primary reserve for aquatic organisms, with water oxygen content affected by temperature and salinity.

Overall, hapnikuvaru is a practical concept describing how much oxygen is available for use by biological or technical systems in any given context.