Cardiovascular - Physiology Questions With Correct Answers 2023 A+ Graded

Stroke Volume is affected by? Increase it with? - ANS-Contractility, Afterload, and Preload ↑ Contractility (like with exercise or anxiety) ↑ Preload (like in early pregnancy) ↓ Afterload A failing heart has what SV? - ANS-↓ SV (Systolic and/or diastolic dysfunction) Contractility and SV increase with? - ANS-Catecholamine stimulation via ß1 receptor ↑ Intracellular Ca2+ ↓ Extracellular Na2+ (↓ activity of Na/Ca exchanger) Digitalis MOA of digitalis increasing Contractility and SV? - ANS-Blocks Na/K pump --> ↑ intracellular Na --> ↓ Na/Ca exchanger activity -- ↑ intracellular Ca MOA of catecholamine stimulation via ß1 receptor increasing Contractility and SV? - ANS-Ca channels phosphorylated --> ↑ Ca entry --> ↑ Ca induced Ca release and ↑ Ca storage in sarcoplasmic reticulum Phospholamban phosphorylation resulting in active Ca ATPase leading to ↑ Ca storage in sarcoplasmic reticulum Contractility and SV decrease with? - ANS--β1-blockade (decrease cAMP) HF with systolic dysfunction Acidosis Hypoxia/hypercapnia (decrease Po2/ increase Pco2) Non-dihydropyridine Ca2+ channel blockers Preload is approximated by? Depends on? What decreases preload? - ANS-Ventricular EDV Depends on venous tone and circulating blood volume Venous vasodilators, like nitroglycerin Afterload approximated by? Increasing afterload results in? - ANS-MAP Increases pressure which increases wall tension via Laplace's Law. After chronic elevation LV compensates for ↑ afterload by hypertrophy in order to ↓ wall tension What decreases afterload? What would decreases both preload and afterload? - ANS-Arterial vasodilators (ie hydralazine) ACE inhibitors and ARBs Laplace's Law? - ANS-Wall tension - pressure x radius Wall stress= (pressure x radius)/ (2 x wall thickness) Myocardial O2 demand is increased by? - ANS--Increased contractility -Increased afterload (proportional to arterial pressure) -Increased heart rate -Increased diameter of ventricle (increased wall tension) SV equation? - ANS-EDV-ESV Ejection Fraction is? Equation? - ANS-Index of ventricular contractility EF=SV/EDV= (EDV-ESV)/EDV EF in systolic HF? In diastolic HF? - ANS-↓ Normal CO output equation? - ANS-SV x HR Fick Priniciple? - ANS-CO = rate of O2 consumption/(arterial O2 content - venous O2 content) How is CO maintained in the early stages of exercise? - ANS-↑ HR and ↑ SV How is CO maintained in the late stages of exercise? - ANS-↑ HR only since SV plateaus Diastole is shortened with ↑↑ HR. This results in? - ANS-↓ diastolic filling time --> ↓ SV -- > ↓ CO Pulse Pressure is directly proportional to? Inversely proportional? - ANS-SV Arterial Compliance Pulse Pressure equation? - ANS-SBP - DBP...