Cardiac physiology plateau phase. The remaining Ca for contraction is released from storage in the sarcoplasmic reticulum. The pattern of prepotential or spontaneous depolarization, followed by rapid depolarization and repolarization just described, are seen in the SA node and a few other conductive cells in the heart. Since the SA node is the pacemaker, it reaches threshold faster than any other component of the conduction system. It will initiate the impulses spreading to the other conducting cells. The SA node, without nervous or endocrine control, would initiate a heart impulse approximately 80–100 times per minute. Although each component of the conduction system
Logical access control Logical access control In computers, logical access controls are tools and protocols used for identification, authentication, authorization, and accountability in computer information systems. Logical access is often needed for remote access of hardware and is often contrasted with the term "physical access", which refers to interactions (such as a lock and key) with hardware in the physical environment, where equipment is stored and used. Logical access controls enforce access control measures for systems, programs, processes, and information. The controls can be embedded within operating systems, applications, add-on security packages, or database and telecommunication management systems. The line between logical access