Atrial systole & ventricular systole occur simultaneously.

Which of the following statements regarding electrical impulses is not true?

Which of the following statements about myocardial cells is true?

Which conduction system property is defined by the ability of the heart cells to receive and transmit an electrical impulse; aka the 'journey'?

Which conduction system property is defined by the ability of the heart muscle cells to respond to an impulse or stimulus; aka the 'reaction'?

Which conduction system property is defined by the ability of the heart to spontaneously initiate an electrical impulse at periodic intervals without requiring an external stimulus; aka the 'beginning'?

Which conduction system property is defined by the ability of the heart muscle cells to shorten in response to an electrical impulse; aka the 'contraction'?

Blood must travel from the atria --> ventricles --> great arteries.

Which conduction pathway is considered the primary pacemaker?

Ventricles must contract before the atria.

Ventricles must contract from base (top) to apex (bottom).

__________ is located at the floor of the RA.

_________ is located within the IVS.

_________ is located at the border of the SVC & RA.

Which conduction system pathway serves as the 'gatekeeper' to delay electrical conduction, preventing excessive atrial impulses from entering the ventricle to allow atrial systole to reach completion before ventricular systole begins?

_________ receives impulse from the AV node.

_________ has a rate of fire of 20 - 40 bpm.

Which conduction system pathway conducts a depolarization wave to the apex of the heart, transferring electrical impulse from atria to ventricles?

Which conduction pathway initiates a self-generating impulse that fuses with atrial muscle fibers, producing atrial contraction?

_________ has a rate of fire at 60 - 100 bpm.

_________ has a rate of fire of 40 - 60 bpm.

Atria communicate with one another via the interatrial tract known as __________.

Which conduction system pathway receives impulse from SA node via 3 internodal tracts?

_________ is a complex network that develops from the bundle branches and spreads through the ventricles.

__________ divides into right & left bundle branches.

Which conduction system pathway spreads electrical impulse throughout ventricles, propelling blood up into the outflow tracts & out to the great arteries?

At the ventricles, stimulation causes depolarization of the cells & contraction occurs from epicardium (outside) --> endocardium (inside).

Which of the following is true regarding atrial kick?

Which of the following is a purpose of AV slowdown? Select all that apply.

During depolarization, chambers are allowed to refill in preparation for contraction again.

Myocardial contraction, state of cellular stimulation, electrical activation, & electrical charge is reversed across cell membranes so interior becomes positively charged are all properties of _____________.

Myocardial relaxation, state of cellular recovery that follows each contraction, cardiac cells return to resting phase of internal negativity, & heart relaxes to allow chambers to refill in preparation of depolarization to occur again are all properties of ______________.

Relaxation happens epicardium --> endocardium during ___________.

Contraction happens endocardium --> epicardium during ____________.

The inherent pacemaker rate of the SA node is ________ than the other pacemaker cells.

__________ is a test that detects & records electrical activity of the heart. Select all that apply.

___________ is a test that records mechanical activity of the heart. Select all that apply.

EKG waveform is recorded from electrical activity during depolarization & repolarization.

_____________ is a period when electrical tracing of the EKG is at zero (or straight line) & no positive or negative deflections are depicted.

Which EKG waveform component is electrical ventricular systole?

Which EKG waveform component is electrical atrial systole?

Which EKG waveform component is electrical ventricular diastole?

__________ is a period of time between 2 activities within the heart.

__________ is considered complete waveforms.

__________ is a portion or part of an electrical tracing.

Atrial depolarization (electrical trigger)

Ventricular repolarization (recovery)

Atrial response (mechanical contraction), AV delay, period of initiation of the impulse until ventricular stimulation, normal length 0.12-0.20 seconds.

Ventricular response (mechanical contraction)

Ventricular depolarization (electrical trigger), atrial repolarization (recovery), normal ventricular depolarization time 0.06-0.12 seconds.

Time required for ventricular depolarization & repolarization

Repolarization of the Purkinje fibers

Horizontal axis on EKG graph paper measures _______.

5 large grid blocks equals _______.

1 large grid block equals ______.

1 small block equals ______.

The vertical axis on EKG paper measures ________.

Select the EKG measurement that correlates to the normal value. 3 to 5 large boxes.

Select the EKG measurement that correlates to the normal value. < 3 small boxes (<0.12 seconds).

Select the EKG measurement that correlates to the normal value. < 1 big box (< 0.2 seconds).

3 second intervals = 15 large grid boxes

______ second EKG strip is needed to calculate heart rate (HR).

HR (bpm) = # QRS (in 6 sec.) x 10

QRS complex farther apart equals _________ HR, and QRS complex closer together equals _________ HR.