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Related to oxygen transport: carbon dioxide transport
1. movement of materials in biologic systems, particularly across the cell membrane into and out of cells or across epithelial layers.
2. in the nursing interventions classification, a nursing intervention defined as moving a patient from one location to another.
active transport see active transport.
oxygen transport the carrying of oxygen through the bloodstream bound to hemoglobin (see oxyhemoglobin).
the process by which oxygen is absorbed by red blood cell hemoglobin in the lungs and carried to the peripheral tissues. Hemoglobin combines with oxygen when present at a high concentration, such as in the lungs, and releases oxygen when the concentration is low, such as in the peripheral tissues. See also hemoglobin.
partial pressurethe component of the total gas pressure accounted for by one gas in a mixture of gases, e.g. in air at 1 standard atmosphere (1 bar, ∼101 kPa, 760 mmHg or torr), 21% is oxygen and the partial pressure of oxygen ( P O2) is ∼21 kPa or 160 mmHg (torr). Partial pressure ( syn tension) of a gas dissolved in a liquid is defined as the partial pressure of that gas in the gaseous phase with which the liquid is, has been or would be, in equilibrium. So, given near-perfect diffusion equilibrium across the alveolar-capillary membranes, blood leaves the lungs with virtually the same P O2 and P CO2 as in alveolar gas (normally close to 100 mmHg P O2 and 40 mmHg P CO2). When blood reaches capillaries in active tissues, the lower P O2 and higher P CO2 in tissue fluids cause net molecular movement towards equilibrium, so that O2 is removed from the blood and CO2 taken up. See also carbon dioxide, diffusing capacity, gas exchange, nitrogen, oxygen, oxyhaemoglobin dissociation curve.
oxygen deliverythe rate of supply of oxygen by the arterial blood to body organs and tissues, expressed as cardiac output (L.min-1)×oxygen content of the blood (L.L-1), e.g. typical resting value would be 5 × 0.2 = 1 L.min-1. This is four times the typical oxygen usage at rest, since only a quarter of the oxygen in the arterial blood is removed by the tissues, reducing haemoglobin saturation from 100% to 75%. See also oxyhaemoglobin dissociation curve.
oxyhaemoglobin dissociation curvethe graph which describes the relationship in the blood between partial pressure of oxygen ( P O2) and the percentage saturation of haemoglobin; it can also show the equivalent oxygen content of the blood when haemoglobin is in normal concentration. With normal lungs, saturation in arterial blood is determined by the P O2 in the alveolar gas with which pulmonary capillary blood equilibrates. The S-shape of the curve has important physiological advantages, e.g. a relatively small decrease in P O2 encountered where blood flows through tissues causes a 'steep' removal of oxygen from the blood; but there needs to be a relatively large decrease in P O2 in the inspired air (and therefore in the alveoli, e.g. at altitude or in a confined space) before there is a serious decline in haemoglobin saturation. ( See fig overleaf .)
a chemical element, atomic number 8, atomic weight 15.999, symbol O. See Table 6. It is a colorless and odorless gas that makes up about 20% of the atmosphere. In combination with hydrogen, it forms water; by weight, 90% of water is oxygen. It is the most abundant of all the elements of nature. Large quantities of it are distributed throughout the solid matter of the earth, because the gas combines readily with many other elements. With carbon and hydrogen, oxygen forms the chemical basis of much organic material. Oxygen is essential in sustaining all kinds of life.
an instrument that measures the concentration of oxygen in a gas mixture.
significant cause of losses in cultivated finfish in enclosed dams, but also in rivers and estuaries, caused by lack of natural aeration of the water or to heavy algal blooms, bushfire ash deposits and overcast conditions leading to respiration rather than photosynthesis or a high concentration of organic matter and leading to the development of a bacterial bloom; a high temperature exacerbates the development.
oxygen flux equation
a calculation that determines the rate at which oxygen is made available to tissues, based on cardiac output and arterial oxygen content.
oxygen-hemoglobin dissociation curve
a graphic explanation of the release and acquisition of oxygen from and to the hemoglobin in the blood in varying circumstances of oxygen partial pressure in the environment.
see reducing valve.
the amount of oxygen bound to hemoglobin in the blood expressed as a percentage of the maximal binding capacity.
oxygen saturation curve
graphical representation describing the relationship (usually curvilinear) between fraction of oxygen-binding sites (of a protein) that have oxygen bound to them and the partial pressure (concentration) of free oxygen.
the heavy metal cylinder in which medical gases are compressed at high pressure. Called also oxygen cylinder.
see tension (2).
an enclosed space or plastic canopy used for oxygen therapy, humidity therapy or aerosol therapy.
supplemental oxygen administered for the purpose of relieving hypoxemia and preventing damage to the tissue cells as a result of oxygen lack (hypoxia). Companion animals are usually placed in a special cage with oxygen piped to it. A mask is used for short-term administration. Large animals can be supplied by a nasal tube taped in place to deliver oxygen into the pharynx.
tissue damage may occur with exposure to high concentrations of oxygen for long periods. See also retrolental fibroplasia.
a functional chain describing the transfer of oxygen from the external environment to the metabolizing tissue; includes uptake in the respiratory system, binding to hemoglobin, transport through the circulatory system, diffusion and dissociation in tissues and utilization in mitochondria, i.e. oxidatable substrates and enzymes.
process of transfer of oxygen around the body either attached to hemoglobin or myoglobin.