释义 |
DictionarySeeshiftchloride shift
chloride shift[′klȯr‚īd ‚shift] (physiology) The reversible exchange of chloride and bicarbonate ions between erythrocytes and plasma to effect transport of carbon dioxide and maintain ionic equilibrium during respiration. chloride shift
shift [shift] a change or deviation.antigenic shift a sudden, major change in the antigenicity of a virus, seen especially in viruses" >influenza viruses, resulting from the recombination of the genomes of two different strains; it is associated with pandemics because hosts do not have immunity to the new strain. See also drift" >antigenic drift.chloride shift the exchange of chloride and carbonate between the plasma and the erythrocytes that takes place when the blood gives up oxygen and receives carbon dioxide. It serves to maintain ionic equilibrium between the cell and surrounding fluid.mediastinal shift a shifting to one side of the tissues and organs of the mediastinum; see also mediastinal shift.shift to the left 1. a change in the blood picture, with a preponderance of young neutrophils.2. an increased oxygen affinity of hemoglobin.shift to the right 1. a preponderance of older neutrophils in the blood picture.2. a decreased oxygen affinity of hemoglobin.weight shift 1. the frequent movement of a paralyzed or partially paralyzed patient to redistribute the patient's weight and prevent impairment of circulation, which leads to pressure sores. One variation is the release" >wheelchair pressure release.2. relocation of a patient's center of mass in order to allow movement; see also gait.chlo·ride shiftwhen CO2 enters the blood from the tissues, it passes into the red blood cells and is converted by carbonate dehydratase to bicarbonate (HCO3-); HCO3- ion passes out into the plasma whereas Cl- migrates into the red blood cells. Reverse changes occur in the lungs when CO2 is eliminated from the blood. Synonym(s): Hamburger phenomenonchlo·ride shift (klōr'īd shift) When CO2 enters the blood from the tissues, it passes into the red blood cell and is converted by carbonate dehydratase to bicarbonate (HCO3-); HCO3- ion passes out into the plasma, whereas Cl- migrates into the red blood cell. Reverse changes occur in the lungs when CO2 is eliminated from the blood. Synonym(s): Hamburger phenomenon.Fig. 100 Chloride shift . The entry of chlorideions (CI-) into a red blood cell from the surrounding plasma. Carbon dioxide is carried into the cell from respiring tissues. chloride shift the movement of chloride ions into a red blood cell (see ERYTHROCYTE) from the plasma. The carriage of carbon dioxide results in an accumulation of bicarbonate ions in the red blood cell, but because of the permeability of the cell membrane to negative ions they readily diffuse out into the plasma. The red blood cell thus develops a net positive charge (because of its retaining positive ions) which is neutralized by inward movement of negative chloride ions from the plasma. This ensures ionic and electrical stability during the transport of carbon dioxide.Hamburger, Hartog J., Dutch physiologist, 1859-1924. Hamburger law - albumins and phosphates pass from red corpuscles to serum, and chlorides pass from serum to cells when blood is acid; the reverse occurs when blood is alkaline.Hamburger phenomenon - movement of chloride from plasma to erythrocyte interior, or vice versa. Synonym(s): chloride shiftchlo·ride shift (klōr'īd shift) When CO2 enters the blood from the tissues, it passes into the red blood cell and is converted by carbonate dehydratase to bicarbonate. Synonym(s): Hamburger phenomenon. |