The primary function of the cardiovascular and pulmonary systems is to produce a flow of oxygenated blood in sufficient supply to maintain aerobic metabolism in all organs and tissues. The system is required to be energy efficient but also receptive to changes in cellular metabolic demand. In order to function both at rest and during demand the system must also match oxygen allocation to metabolic requirements at a localised level. Once blood enters an area that requires substrates, oxygen should have the capacity to efficiently move from the blood, across the vessel wall and into the tissue. Global oxygen delivery (DO2, product of cardiac output and arterial oxygen content) under normal, resting conditions is more than adequate to meet metabolic demands/oxygen consumption (VO2) (Figure 1.1). At a tissue level, oxygen delivery is governed by two processes, convective and diffusive oxygen transport. Convective transport can be described as the bulk movement of oxygen in the blood, encompassing changes in cardiac output and the mechanisms that regulate flow in the microcirculation. Diffusive oxygen transport simply refers to the movement of oxygen from the blood into tissue, down the capillary-intracellular oxygen tension (PO 2) gradient and is governed by arterial oxygen tension (PaO2).
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:584709 |
| Date | January 2009 |
| Creators | Pinder, Andrew George |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/55834/ |
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