leon schram ap computer science answer key

CT: crista terminalis, CTL: control, Endo: endocardium, Epi: epicardium, IVC: inferior vena cava, RA: right atrium, RYAN: ryanodine, SEP: inter-atrial septum, SVC: superior vena cava E) Slowing of SAN beat rate also occurs with ryanodine, a blocker of RyR Ca 2+ release, demonstrating the importance of the Ca 2+ clock in contributing to normal SAN pacemaking (with permission from ( 64)). D) Ivabradine, an I f blocker, slows SAN beat rate via slowing the rate of diastolic depolarization (with permission from ( 85)). C) Example APs and ionic currents from central and peripheral SAN cells. B) Transmural view of SAN showing organization of central and peripherial SAN cells.

Approximate area of functional conduction block is shown in gray. For a more detailed discussion of methodologies pertaining to these findings, the reader is referred to the following excellent methodological reviews ( 453).Ī) Schematic showing endocardial view of SAN area (location corresponds to box around SAN in Figure 1A). Both experimental and computational findings are discussed throughout this review. Finally, a discussion of both inherited and acquired cardiac disease is covered, including what is currently known about pathology-induced remodeling of ion channels.

Heterogeneity within each region is then highlighted, with particular emphasis on species differences and atrioventricular differences discussed in the ventricular section.

For each major region of the heart, function, ionic mechanisms, and molecular bases are first discussed ( Figure 1C). The review is organized functionally following the propagation of the AP (SAN, atrium, AVN, His-Purkinje system, ventricles). In this review, the molecular and ionic bases of regionally defined electrophysiology are summarized, along with region-specific heart disease-induced remodeling and its functional consequences. The molecular and ionic bases of regionally defined electrophysiology are reviewed here, along with region-specific heart disease-induced remodeling and its functional consequences. The various cardiac regions are characterized by specific action potential (AP) morphology and duration, which result from regionally distinct collections of ionic currents. From the AVN, electrical activity passes rapidly through the cable-like His-Purkinje system to reach the ventricles, triggering coordinated cardiac pumping action.

The normal cardiac impulse originates in the sinoatrial node (SAN) and propagates through the atria to reach the atrioventricular node (AVN).

Leon schram ap computer science answer key