Which answer best defines a biopotential?
An electrical gradient in living cells.
Kinetic energy in an organism.
All of the things a human can do on their lifetime.
The ions in a cell.
Excitable tissue is defined by its ability to
Respond to changes in the environment.
Generate electricity.
Create an action potential
All of these are true.
Which series of events in the cardiac cycle occurs first?
Electrical
Mechanical
What is the benefit of a 12-lead ECG? In other words, why isn’t one lead sufficient?
Multiple leads provide a 3 dimensional image of the electrical activity of the heart.
Each additional lead duplicates and verifies the others.
There is no benefit.
When reading an ECG the vertical axis is calibrated in millivolts seconds( millivolts, seconds ) while the horizontal axis is calibrated in millivolts seconds( millivolts, seconds ).
What wave on an ECG indicates depolarization of the atria?
P wave
QRS Complex
T wave
PQ interval
QT interval
What portion of an ECG indicates the time it takes for an electrical impulse to reach the ventricles?
PR interval
Which of the following is not represented by a specific wave on a typical electrocardiogram?
depolarization of the atria
repolarization of the atria
depolarization of the ventricles
repolarization of the ventricles
Which happens first?
A positive T-wave is generally an indication of a cardiac abnormality.
True
False
When referring to cardiac rhythm, what does the term irregular refer to?
No R-R interval differs from any other R-R interval by more than 0.12 second.
No R-R interval differs from any other R-R interval by more than 0.06 second.
Less than 75 beats in one minute.
More than 75 beats in one minute.
Given the following information, determine the heart rate as precisely as the rules allow. Heart rhythm is irregular There are 6 R-waves in 6-inch tracing There are 6.7 R-R intervals in 6-inch tracing
Heart rate is: 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70( 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70 ) bpm
If the R-R interval on an ECG tracing increases, heart rate must be:
increasing.
decreasing.
During a cardiac cycle, which valves close first?
Atrioventricular (AV) valves
Semilunar (SL) valves
The semilunar valves close when ventricular pressure:
rises
falls
If the amplitude of a pulse wave increases this would be a rough in indication that stroke volume is:
increasing
decreasing
