Notes in 2. Electrical Activity of the Heart and ECG Basics

To Subscribe, use this Key

Status	Last Update	Fields
Published	02/10/2024	The {{c1::desmosomes (physical connection)}} and {{c1::gap junctions (electrical connection)}} cause the heart cells to contract as one big …
Published	02/10/2024	The actin-myosin binding sites do not become {{c1::fully saturated}} in cardiac muscle, compared to skeletal muscle, which allows regulation by c…
Published	02/10/2024	The length of the Skeletal muscle action potential is {{c1::shorter}} than Cardiac muscle action potential
Published	02/10/2024	What is the significance of Cardiac Muscle having a long action potential?[1] {{c1::Long refractory period prevents tetanic contraction}}[2] {{c1…
Published	02/10/2024	Summation in skeletal muscle leads to {{c1::tetanus}}, which would be fatal if it happened in the heart.
Published	02/10/2024	{{c1::Resting Membrane Potential (RMP)}} for non-pacemaker cells is at {{c2::-90}} mV
Published	02/10/2024	The main difference between the action potential of the myocardial contractile cell and those of skeletal muscle fibers and neurons is that: {{c1…
Published	02/10/2024	Describe the phases of an action potential in a contractile cell (non-pacemaker)
Published	02/10/2024	In a non-pacemaker cell, the resting membrane potential is about -90 mV due to the {{c1::high resting PK+}}
Published	02/10/2024	In a non-pacemaker cell, the {{c2::depolarisation}} phase occurs due to an {{c1::increase in PNa+}}
Published	02/10/2024	In a non-pacemaker cell, the {{c2::plateau}} phase occurs due to an {{c1::increase in PCa2+ (L-type)}} and a {{c1::decrease in PK+}}
Published	02/10/2024	In a non-pacemaker cell, the {{c2::repolarisation}} phase occurs due to a {{c1::decrease in PCa2+}} and an {{c1::increase in PK+}}
Published	02/10/2024	The pacemaker potential (pre-potential) is an unstable membrane potential, that starts at {{c2::-60}} mV, and spontaneously heads toward threshol…
Published	02/10/2024	In a pacemaker cell, the {{c2::depolarization}} phase occurs due to an {{c1::increase in PCa2+ (L-type)}}
Published	02/10/2024	The pacemaker features of the heart explains {{c1::autorhythmicity}} which is its own intrinsic rhythm without nerve intervention.
Published	02/10/2024	The speed with which pacemaker cells {{c1::depolarize}} determines the {{c2::heart rate}}.
Published	02/10/2024	Depolarization begins in the {{c1::Sinoatrial Node (SA node)}} which is the main pacemaker of the heart.conduction rate ~ 0.5 m/sec
Published	02/10/2024	The {{c1::annulus fibrosus}} is the only non-conducting part of the heart that separates atrium from ventricles.
Published	02/10/2024	The {{c1::Atrioventricular Node (AV node)}} are myocardial cells involved in the conduction of action potential which connect the atria and ventricles…
Published	02/10/2024	{{c1::Bundle of His}} and {{c1::Purkinje fibres}} are both specialized conducting cells of the ventricles which form the rapid conduction system.
Published	02/10/2024	The Conducting System of the Heart{{c1::Sinoatrial Node}} → {{c1::Atrioventricular Node}} → {{c1::Bundle of His}} → {{c1::Purkinje Fibres}} → {{c1::Ap…
Published	02/10/2024	The {{c1::AV node}} is the only structure through which action potentials can reach the contractile fibers of the ventricles.
Published	02/10/2024	{{c1::P wave}} corresponds to {{c2::atrial depolarisation}}
Published	02/10/2024	{{c1::QRS complex}} corresponds to {{c2::ventricular depolarisation}}
Published	02/10/2024	{{c1::T wave}} corresponds to {{c2::ventricular repolarisation}}
Published	02/10/2024	The cardiac action potential is long due to depolarisation secondary to an increase in {{c1::L-type Ca2+}}
Published	02/10/2024	The conduction rate of the Sinoatrial Node is around {{c1::0.5}} m/sec
Published	02/10/2024	The conduction rate of the Atrioventricular Node is around {{c1::0.05}} m/sec, which is why it is known as the delay box.
Published	02/10/2024	The conduction rate of the Bundle of His and Purkinje Fibres is around {{c1::5}} m/sec
Status	Last Update	Fields