A & P: EKG Tracings

How may electrodes are used in a standard ECG?

• 10

• 12

• 4

• 6

Answer explanation

4 limb electrodes and 6 chest electrodes are used for a total of 10 electrodes.

Where does the electrical impulse travel after leaving the AV bundle?

• SA Node

• Right & Left Bundle Branches

• Bundle of His

• Purkinje Fibers

The normal ECG is composed of ____. (select all that apply).

• waves

• complexes

• segments

• intervals

The ability for the heart cells to transmit electrical current from cell to cell is known as _____.

• irritability

• contractility

• automaticity

• conductivity

Which phase of action potential represents initial repolarization of the cells?

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

What are the three primary electrolytes responsible for the electrical difference across the resting membrane potential? (select all that apply)

• Potassium

• Sodium

• Calcium

• Bicarbonate

Which phase of action potential represents initial repolarization of the myocardial cells?

• Phase 0

• Phase 1

• Phase 2

• Phase 3

• Phase 4

After the electrical impulse leaves the AV junction, where does it travel next?

• Purkinje Fibers

• bundle of his

• Bachmann's bundle

• bundle branches

What is an alternate term for "pacemaker cells"?

• autorhythmic cells

• sympathetic neural fibers

• contractile muscle fibers

• atrial muscle fibers

What is the term for the unique ability of cells in the SA node to generate an action potential without being stimulated?

• excitability

• conductivity

• automaticity