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CARDIAC REGULATION. EXTRINSIC AND INTRINSIC MECHANISMS. Guido E. Santacana Ph.D. Professor Dept. of Physiology. Control of Cardiac Activity. CARDIAC OUTPUT = HEART RATE X STROKE VOLUME. Pacemaker Activity. Myocardial Performance. TWO POINTS TO REGULATE. EXTRINSIC REGULATION.
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CARDIAC REGULATION EXTRINSIC AND INTRINSIC MECHANISMS Guido E. Santacana Ph.D. Professor Dept. of Physiology
Control of Cardiac Activity CARDIAC OUTPUT = HEART RATE X STROKE VOLUME Pacemaker Activity Myocardial Performance TWO POINTS TO REGULATE
EXTRINSIC REGULATION • AUTONOMIC NERVES • BARORECEPTOR REFLEX • BAINBRIDGE REFLEX • RESPIRATORY EFFECTS • CHEMORECEPTOR REFLEXES • VENTRICULAR RECEPTOR REFLEX • HORMONAL REGULATION
EXTRINSIC INNERVATION OF THE HEART THORACIC CERVICAL MEDULLA OBLONGATA R VAGUS EPICARDIAL PLEXUS SAN L CORONARY VESSELS AVN MYOCARDIUM
SYMPATHETIC VS VAGAL STIMULATION AND DECAY VAGAL HEART RATE (B/MIN) SYMPATHETIC
PARASYMPATHETIC / SYMPATHETICREASONS FOR STIMULATION/DECAYDIFFERENCES VAGUS SYMP. DIFUSSION Ach NPY NE K+ REUPTAKE ATROPINE NE Ach B BLOCKERS B1 M AchE cAMP
EFFECTS OF CATECHOLAMINES EPINEPHRINE NOREPINEPHRINE
BARORECEPTOR REFLEX AORTIC ARCH CAROTID SINUS 200 HEART RATE B/M 50 150 ARTERIAL PRESSURE mmHg
BAINBRIDGE VS BARORECEPTOR REFLEXES VOLUME LOAD + + ARTERIAL PRESSURE CO INCREASED RA PRESSURE + + ATRIAL RECEPTORS BARORECEPTOR REFLEX + - BAINBRIDGE REFLEX + HEART RATE
RESPIRATORY REGULATION OF CARDIAC ACTIVITY INSPIRATION BARORECEPTOR REFLEX + + ARTERIAL PRESSURE INTRATHORACIC PRESSURE CO + + VENOUS RETURN BAINBRIDGE
PERIPHERAL CHEMORECEPTORS AND HEART RATE + - PERIPHERAL CHEMORECEPTORS HEART RATE MEDULLA + - DAMPENING OF CARDIAC EFFECT RESPIRATORY ACTIVITY
VENTRICULAR RECEPTOR REFLEX VASOVAGAL SYNCOPE STANDING VENTRICULAR CONTRACTION VENOUS POOLING SYMPATHETIC ACTIVITY CO MAP BARO REFLEX VENOUS RETURN
HUMORAL REGULATION INSULIN THYROID GLUCAGON dP/dt CATECHOLAMINES POTENTIATION STEROIDS
INTRINSIC REGULATION • FRANK STARLING • HEART RATE AND FORCE
INTRINSIC REGULATIONOF THE HEART FRANK STARLING LAW OF THE HEART AND BACK TO THE VENTRICULAR FUNCTION CURVE :>) LVP EDV
FORCE DEVELOPMENT .32 FORCE DEVELOPED(G) 1.6 180 INTERVAL BETWEEN CONTRACTIONS(SEC)