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Effetti Acuti Cardiovascolari ed Esercizio Fisico. Risposta Cardiovascolare all’Esercizio Acuto. Fase preparatoria iniziale Stimolazione adrenergica Vasocostrizione distrettuale Fase intermedia metabolica Fattori locali Stimolazione adrenergica.
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Risposta Cardiovascolare all’Esercizio Acuto • Fase preparatoria iniziale Stimolazione adrenergica Vasocostrizione distrettuale • Fase intermedia metabolicaFattori locali Stimolazione adrenergica
Risposta Cardiovascolare all’Esercizio Acuto • Fase preparatoria iniziale • Stimolazione adrenergica (cuore) • vasocostrizione distrettuale
Risposta Cardiovascolare all’Esercizio Acuto Fase preparatoria iniziale Stimolazione adrenergica (cuore)
Event 60 yards 220 yards 440 yards 880 yards 1 mile 2 mile Resting, anticipatory, and maximum exercise heart rate in competitive runners and untrained subjects during all-out running EXERCISE T UT 177 162 186 189 194 198 206 199 ANTICIP T UT 124 115 118 129 128 108 109 REST T UT 69 67 67 63 70 64 59 74 McArdle W.D. Telemetred cardiac response to selected running events J. Appl. Physiol. 23:566,1967 T = Trained UT = Untrained
Activator Activation of motor cortex and higer areas of brain causes increase in sympathetic outflow and reciprocal inhibition of parasympathetic activity Response Acceleration of heart rate; increased myocardial contractility; vasodilatation in skeletal and heart muscle (cholinergic fibres); vasoconstriction in other areas, especially in skin,gut,spleen, liver and kidneys (adrenergic fibres); increase in arterial blood pressure. Integreted chemical,neural and hormonal adjustaments prior to and during exercise Preexercise “anticipatory” response
Continued sympathetic cholinergig outflow; alterations in local metabolic conditions due to hypoxia, pH, CO2, ADP, Mg++, Ca++, temperature. Continued sympathetic adrenergic outflow in conjunction with epineprhine and norepineprhine from the adrenal medulla Further dilatation of muscle vasculature Concomitant constriction of vasculature in inactive tissues to maintain adeguate perfusion pressure throu ghout arterial system. Venous vessels stiffen to reduce their capacity. This venoconstrinction facilitates venous return and maintainsthe central blood volume Integreted chemical,neural and hormonal adjustaments prior to and during exercise Response Activator Condition EXERCISE
1% 4% 5% 4% Rest 3-5 Lmin Exercise 25-30 Lmin CRMS Distribution of Flow at rest and during Acute Exercise
Heart Rate in Response to Exercise HR Watts
Change of Left Ventricular Ejection Fraction from Rest to Exercise
Blood Pressure =CO x Peripheral Resistance In normal subjects exercise increases Cardiac Output and/or decreases Peripheral Resistance
Exercise and Blood Pressure normal subjects Men < 20 Systolic Diastolic Men > 20 Systolic Diastolic
Coronary Flow and Heart Rate Cor.Flow HR
Cardiovascular Response to Exercise Coronary Flow Cc/min/100gr Myocardial O2 Cosumption cc/min/100gr Watts
25% Radius 63% Area Vasoconstriction (Acute Exercise) 17% Radius 96% Area Exercise,Vasoconstriction and Coronary Flow
H.R. b/min Cycloergometer Recovery Cardiovascular Response to Acute Exercise in trained subjects
Cardiovascular Response to Acute Exercise in trained subjects