E. (1) sea shell fossils (2) it is made of old ocean floor that got uplifted during collision. 4. At convergent plate boundaries, the volcanic mountain chains that form are called (1) ________ in an ocean-. ocean setting and (2) __________ in an ocean-continent setting.
Poor R wave progression is a vague term used to describe the transition in voltage in the precordial leads of an electrocardiogram (ECG). It is not a diagnosis but simply describes a pattern frequently noted. In a normal individual there is a progressive increase in the magnitude of the voltage in the leads from V1 to V4.
T wave. The T wave represents ventricular repolarization and is longer in duration than depolarization (i.e., conduction of the repolarization wave is slower than the wave of depolarization). Sometimes a small positive U wave may be seen following the T wave (not shown in figure at top of page).he different waves that comprise the ECG represent the sequence of depolarization and repolarization of the atria and ventricles. The ECG is recorded at a speed of 25 mm/sec, and the voltages are calibrated so that 1 mV = 10 mm in the vertical direction.