Ch 18 - Module 4
The role of the atrioventricular node (AV node) is to ____.
slow down impulses so that the atria can contract to fill the adjacent ventricles
The absolute refractory period refers to the time during which __________.
the muscle cell is not in a position to respond to a stimulus of any strength
Identify the part of the cardiac conduction system indicated by "A."
SA node
The normal pacemaker of the heart is the __________.
SA node
Which term describes an area of the heart conduction system with the fastest depolarizing pacemaker cells?
SA node
The P wave of an electrocardiogram represents
atrial depolarization
The ability of some cardiac muscle cells to initiate their own depolarization and cause depolarization of the rest of the heart is called __________.
automaticity
Match the following term to its correct description: Systole.
Contraction
Identify the parts of the cardiac conduction system indicated by "C."
Subendocardial conducting network
Match the following term with its correct description: Ventricular repolarization.
T wave
Match the following term with its correct description: Atrial depolarization.
P wave
Choose the correct sequence of current flow through the intrinsic conduction system of the heart.
SA node, AV node, AV bundle, right and left bundle branches, subendocardial conducting network
Which term describes an area of the heart conduction system where the impulse is delayed for 0.1 sec?
AV node
Match the following term with its correct description: Ventricular repolarization.
QRS complex
Which of the following is a difference between cardiac muscle and skeletal muscle?
Unlike skeletal muscle cells, cardiac muscle has gap junctions between cells (that allow them to be autorhythmic).
The __________ nerve carries parasympathetic fibers to the sinoatrial (SA) node.
Vagus
Identify the part of the ECG indicated by "C."
Ventricular repolarization
The cells of the myocardium behave as a single, coordinated unit called a __________.
functional syncytium
