13. Blood Gas Transport
The respiratory system is responsible for ensuring that the oxygen in the air we breathe reaches the cells of our body, and that the carbon dioxide produced by the cells is eliminated. This process is accomplished by transporting gases in the blood, a vital component of the respiratory system.
Oxygen
Oxygen is transported in the blood in two ways. Approximately 98% of oxygen is carried by red blood cells in the blood, binding to haemoglobin. Hemoglobin is an iron-rich protein that gives red blood cells their red color. When oxygen binds to hemoglobin, oxyhemoglobin is formed. The remaining 2% of the oxygen is dissolved directly in the blood plasma.
Carbon Dioxide
Carbon dioxide is produced as a waste product of cellular metabolism and must be removed from the body. About 7% of carbon dioxide is transported dissolved in blood plasma, while 23% is transported in red blood cells bound to haemoglobin, forming carbaminohemoglobin. Most carbon dioxide (70%) is transported in the blood as bicarbonate ions.
Gas Transport and the Circulatory System
The circulatory system works in conjunction with the respiratory system to transport gases throughout the body. Oxygen-rich blood from the heart is pumped to the rest of the body through the arteries. Cells use oxygen and produce carbon dioxide as a by-product. The blood, now low in oxygen and high in carbon dioxide, returns to the heart through the veins and is pumped to the lungs, where the carbon dioxide is expelled and the blood is oxygenated again.
Importance of Gas Transport
The efficient transport of gases is vital for survival. Without oxygen, cells cannot produce enough energy for their vital functions. Likewise, carbon dioxide buildup can lead to acidification of the blood, a potentially life-threatening condition known as respiratory acidosis.
In summary, the transport of gases in the blood is a vital process that allows our cells to breathe and function properly. It is a wonderful example of the complexity and efficiency of the human body.
