Chemistry

The blood - a buffer in our body


Blood is vital to the functioning of our body. One of the functions of arterial blood is to carry oxygen (from the air we breathe) from the lungs to the cells.

Following the opposite path, venous blood brings carbon dioxide (released by the metabolism of cells) into the lungs and, through them, carbon dioxide is exhaled at expiration. For gas exchange to occur normally, the blood must be buffered to a pH close to 7.4.

One of the systems that contribute to blood buffering is H2CO3 and NaHCO3.

If breathing becomes slow due to breathing problems, there will be poor CO2, which will cause the balance to shift

CO2 + H2O ↔ H2CO3 + H + + HCO3-

to the right, increasing the concentration of H + ions and making the blood more acidic.

With a pH lower than 7.35, there is a blood acidosis. Its main symptom is disorientation, followed by coma and death.

Conversely, if breathing becomes accelerated due to intense exercise or climbing at high altitudes, when the body absorbs more oxygen, carbon dioxide will be eliminated more. This will make the blood more basic. Its pH will be higher than 7.45, so there is a blood alkalosis.

The initial symptom is seizures that can lead to death.