oxyhemoglobin dissociation curve

oxyhemoglobin dissociation curve,

a graphic expression of the affinity between oxygen and hemoglobin or of the amount of oxygen chemically bound at equilibrium to the hemoglobin in blood as a function of oxygen pressure. The curve also includes the pH, temperature, and carbon dioxide pressure.

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curve [kerv]

a line that is not straight, or that describes part of a circle, especially a line representing varying values in a graph.

dose-effect curve (dose-response curve) a graphic representation of the effect caused by an agent (such as a drug or radiation) plotted against the dose, showing the relationship of the effect to changes in the dose.

growth curve the curve obtained by plotting increase in size or numbers against the elapsed time.

oxyhemoglobin dissociation curve a graphic curve representing the normal variation in the amount of oxygen that combines with hemoglobin as a function of the partial pressures of oxygen and carbon dioxide. The curve is said to shift to the right when less than a normal amount of oxygen is taken up by the blood at a given Po₂, and to shift to the left when more than a normal amount is taken up. Factors influencing the shape of the curve include changes in the blood pH, Pco₂, and temperature; the presence of carbon monoxide; alterations in the constituents of the erythrocytes; and certain disease states.

pulse curve sphygmogram.

Spee curve (curve of Spee) the anatomic curvature of the occlusal alignment of teeth, beginning at the tip of the lower canine, following the buccal cusps of the premolars and molars, and continuing to the anterior border of the ramus.

strength-duration curve a graphic representation of the relationship between the intensity of an electric stimulus at the motor point of a muscle and the length of time it must flow to elicit a minimal contraction; see also chronaxie and rheobase. In cardiac pacing it is useful in determining characteristics of a particular pacing electrode and determining the most efficient selection of pacing parameters for an appropriate safety margin.

survival curve a graph of the probability of survival versus time, commonly used to present the results of clinical trials, e.g., a graph of the fraction of patients surviving (until death, relapse, or some other defined endpoint) at each time after a certain therapeutic procedure.

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oxyhemoglobin

hemoglobin combined with molecular oxygen, the form in which oxygen is transported in the blood. See also hemoglobin.

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oxyhemoglobin dissociation curve

see hemoglobin-oxygen dissociation curve.