Cardiac Structure and Control

Structure of Cardiac Muscle

Ionic Concentrations

Cardiac Depolarization

Myocardial Contraction

Cardiovascular Control Center

Baroreceptor Resetting

Baroreceptor Resetting

Summary of Cardiac Responses to Exercise Central command activation of CVC Decreased vagal tone Baroreceptor set point increases Increased hypothalamic input Increased muscle afferent input Increased plasma catecholamines

Summary of Cardiac Adaptations Increased parasympathetic tone Decreased intrinsic rate Increased heart size Increased diastolic filling time Increased blood volume Increased ventricular compliance Increased contractility