BIO202 19.2 Cardiac Muscle and Electrical Activity
Medical device that transmits electrical signals to the heart to ensure that it contracts and pumps blood to the body.
Artificial pacemaker
__________ is masked by ventricular depolarization.
Atrial repolarization
Also, bundle of His.
Atrioventricular bundle
Group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum.
Atrioventricular bundle
Lead to the Purkinje fibers and also to the right papillary muscle via the moderator band.
Atrioventricular bundle branches
Specialized myocardial conductile cells that arise from the bifurcation of the atrioventricular bundle and pass through the interventricular septum.
Atrioventricular bundle branches
Clump of myocardial cells located in the inferior portion of the right atrium within the atrioventricular septum.
Atrioventricular node
Receives the impulse from the SA node, pauses, and then transmits it into specialized conducting cells within the interventricular septum.
Atrioventricular node
Ability of cardiac muscle to initiate its own electrical impulse that triggers the mechanical contraction that pumps blood at a fixed pace without nervous or endocrine control.
Autorhythmicity
Also, interatrial band.
Bachmann's bundle
Group of specialized conducting cells that transmit the impulse directly from the SA node in the right atrium to the left atrium.
Bachmann's bundle
Also, atrioventricular bundle.
Bundle of His
Form the left and right atrioventricular bundle branches.
Bundle of His
The influx of which ion accounts for the plateau phase?
Calcium
Only __________ is capable of autorhythmicity.
Cardiac muscle
Also abbreviated as EKG
Electrocardiogram
ECG
Electrocardiogram
Surface recording of the electrical activity of the heart that can be used for diagnosis of irregular heart function.
Electrocardiogram
Interruption in the normal conduction pathway.
Heart block
Physical junction between adjacent cardiac muscle cells; consisting of desmosomes, specialized linking proteoglycans, and gap junctions that allow passage of ions between the two cells.
Intercalated disc
Specialized conductile cells within the atria that transmit the impulse from the SA node throughout the myocardial cells of the atrium and to the AV node.
Internodal pathways
Specialized cells that transmit electrical impulses throughout the heart and trigger contraction by the myocardial contractile cells.
Myocardial conducting cells
Bulk of the cardiac muscle cells in the atria and ventricles that conduct impulses and contract to propel blood.
Myocardial contractile cells
Component of the electrocardiogram that represents the depolarization of the atria.
P wave
Cluster of specialized myocardial cells known as the SA node that initiates the sinus rhythm.
Pacemaker
The __________ prevents additional impulses from spreading through the heart prematurely, thereby allowing the muscle sufficient time to contract and pump blood effectively.
Plateau phase
Also, spontaneous depolarization.
Prepotential depolarization
Specialized myocardial conduction fibers that arise from the bundle branches and spread the impulse to the myocardial contraction fibers of the ventricles.
Purkinje fibers
Component of the electrocardiogram that represents the depolarization of the ventricles and includes, as a component, the repolarization of the atria.
QRS complex
A specialized clump of myocardial conducting cells located in the superior portion of the right atrium that has the highest inherent rate of depolarization that then spreads throughout the heart.
Sinoatrial node
Known as the pacemaker.
Sinoatrial node
Normal contractile pattern of the heart.
Sinus rhythm
Also, prepotential depolarization.
Spontaneous depolarization
Mechanism that accounts for the autorhythmic property of cardiac muscle.
Spontaneous depolarization
The membrane potential increases as sodium ions diffuse through the always-open sodium ion channels and causes the electrical potential to rise.
Spontaneous depolarization
Component of the electrocardiogram that represents the repolarization of the ventricles.
T wave
