Systemic Oxygen Transport
Normal tissue metabolism is intimately dependent upon an adequate supply of oxygen and it is the primary function of the oxygen transport system to supply this oxygen to the tissues. In a simple single-cell organism such as the amoeba transport of oxygen is accomplished by simple diffusion into the cell from the surrounding aqueous medium. Even insects are sustained by simple diffusion of oxygen from the surrounding atmosphere with the aid of a system of air ducts penetrating the body. However, when organisms are larger and more complex simple diffusion is no longer adequate to maintain oxygenation and a specific system must be introduced to transport oxygen from the surrounding environment to the cells of the body. The basic requirement for this system is to bring adequate quantities of oxygen to the tissues at sufficient partial pressure to permit rapid diffusion of oxygen in sufficient quantity from the blood to the tissue. The intracellular oxygen tension must be adequate to maintain metabolic processes. As long as these basic requirements are met, the oxygen transport system is a success. We will discuss two topics relating to this oxygen transport system. The first is the relationship between oxygen transport and the regulation of red cell production and the second considers the comparative physiology of oxygen transport in several animal species.
KeywordsOxygen Tension Arterial Oxygen Oxygen Transport Dissociation Curve Arterial Oxygen Saturation
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