Cardiac Anatomy and Conduction System Review

Flashcards covering cardiac anatomy, blood flow, cardiac conduction system rates, and EKG lead placement.

Endocardium

The inner layer of the heart wall that forms the heart valves.

Myocardium

The middle heart layer containing cardiac muscle that contracts to pump blood.

Epicardium

The outer layer of the heart wall that contains the coronary arteries.

Pericardium

The protective sac surrounding the heart.

Heart Valves

Structures within the endocardium layer whose purpose is to prevent the backflow of blood.

Arteries

Blood vessels that always carry blood AWAY from the heart.

Veins

Blood vessels that always carry blood TOWARDS the heart.

Widow Maker

The common term for the occlusion of the Left Anterior Descending (LAD) coronary artery.

Automaticity

The ability of the cardiac conduction system cells to initiate their own electrical impulse independently.

SA Node

The primary pacemaker of the heart, located in the right atrium, with an intrinsic rate of $60\text{--}100\text{ BPM}$.

Bachmann's Bundle

The conduction pathway that connects the SA node to the left atrium.

Internodal Pathway

The electrical pathway that connects the SA node to the AV node.

AV Node

The gate keeper of the conduction system, located in the right atrium, with an intrinsic rate of $40\text{--}60\text{ BPM}$.

Purkinje Fibers

The terminal fibers of the cardiac conduction system with an intrinsic rate of $20\text{--}40\text{ BPM}$.

P Wave

The wave on an EKG tracing that represents atrial depolarization.

QRS Complex

The sequence on an EKG tracing that represents ventricular depolarization.

T Wave

The wave on an EKG tracing that represents ventricular repolarization.

Four Limb Leads

The standard limb electrodes labeled RA, LA, RL, and LL.

Six Precordial Leads

The standard chest electrodes labeled V1, V2, V3, V4, V5, and V6.

Grounding Lead

The RL (Right Leg) electrode placement on an EKG.