A book contains information about a structure, functions, ontogenesis, adjusting of functions of heart in a norm and at functional violations. Authors aspired to the synthesis of classic ideas about nature of cardiac activity, mechanisms of her миогенной, reflex and гуморальной adjusting, and also results of modern physiological, molecular-biological and biochemical researches.The special attention is spared to physiological to the ground of the most widespread instrumental methods of research of electric activity, biomechanics a pump and endocrine functions of heart (электро-, фоно- and echocardiography electromagnetic and ultrasonic флоуметрия), and also questions of interpretation of data of clinical functional diagnostics and fundamental experimental researches.A manual is intended for students biological and medical institutions of higher learning, graduate students, clinical interns, wide circle of biologists, researchers, teachers and practicing doctors.