- Rate of change of temperature, pressure, magnetic field, or other variable as a function of distance, time, etc.- density g. a solution in which the concentration (density) of a solute increases in a continuous fashion from top to bottom, or end to end, of a container ( e.g., the centrifuge tube in density-g. centrifugation). SYN: concentration g..- electrochemical g. a measure of the tendency of an ion to move passively from one point to another, taking into consideration the differences in its concentration and in the electrical potentials between the two points; commonly expressed as the additional voltage needed to achieve equilibrium.- magnetic field g. in magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow calculation of their spatial position. SYN: field g..- systolic g. the difference in pressure during systole between two communicating cardiovascular chambers, e.g., between the left ventricle and aorta in aortic stenosis.- ventricular g. the algebraic sum of ( i.e., the net electrical difference between) the area enclosed within the QRS complex and that within the T wave in the electrocardiogram.
* * *gra·di·ent 'grād-ē-ənt n1) change in the value of a quantity (as temperature, pressure, or concentration) with change in a given variable and esp. per unit on a linear scale2) a graded difference in physiological activity along an axis (as of the body or an embryonic field)3) change in response with distance from the stimulus
* * *gra·di·ent (graґde-ənt) 1. the increase or decrease of one variable expressed as a function of a second. 2. the graphic representation of such a change.
Medical dictionary. 2011.