Cardiac and vascular function curves
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Cardiovascular system
Physiology
![NOTES NOTES CARDIAC CYCLE MEASURING CARDIAC OUTPUT FICK PRINCIPLE osms.it/Fick-principle ▪ Model used to measure cardiac output (CO) ▫ Output of left, right ventricles equal during normal cardiac function ▪ Steady state: rate of O2 consumption = amount of O2 leaving lungs via pulmonary vein - amount of O2 returning via pulmonary arteries x CO ▪ Pulmonary blood flow of right heart = CO of left heart: used to calculate CO Cardiac Output = O2 consumption [O2] pulmonary vein - [O2] pulmonary artery ▪ 250mL/minute = total O2 consumption (70kg, biologically-male individual); pulmonary venous O2 content = 0.20/mL; pulmonary arterial O2 content = 0.15/mL Cardiac Output = 250mL/min = 5000mL/min 0.20mL - 0.15mL ▪ Also measures blood flow to individual organs ▫ Renal blood flow = renal O2 consumption / renal arterial O2 - renal venous O2 CARDIAC & VASCULAR FUNCTION CURVES osms.it/cardiac-and-vascular-function-curves ▪ Curves depicting functional connections between vascular system, right atrial pressure, and CO CARDIAC FUNCTION CURVE (CO CURVE) ▪ Plot of relationship between left ventricle (LV) CO, right atrial (RA) pressure ▪ Based on Frank–Starling relationship describing CO dependence on preload ▫ Preload (determined by RA pressure), independent variable; CO, dependent variable ▫ ↑ venous return → ↑ RA pressure → ↑ LV end-diastolic volume (EDV)/preload, myocardial fiber stretch → ↑ CO ▫ LV CO (L/min) = LV venous return/ preload (RA pressure in mmHg) ▫ Relationship remains intact with steady state of venous return ▫ RA pressure 4mmHg → curve levels off at maximum 9L/min OSMOSIS.ORG 111](https://d16qt3wv6xm098.cloudfront.net/frhMThDfSAm-dds1kgRyp5irSyax-t1W/thumb-1.jpg)
Cardiac and vascular function curves exam links
Cardiac and vascular function curves depict the functional relationship between the vascular system, the right atrial pressure, and the cardiac output. The vascular system is a network of arteries, veins, and capillaries that carry blood throughout the body. The arteries are the blood vessels that carry blood away from the heart, whereas veins are the blood vessels that carry blood back to the heart.
The capillaries are the small blood vessels that connect the arteries and veins. Right atrial pressure refers to the blood pressure in the right heart atrium. Blood in the right atrium reflects the amount of blood that's returned to the heart and can help assess the heart's ability to pump it in the arterial system. The cardiac output (CO) is the amount of blood that the heart pumps out in one minute. It is equal to the stroke volume times the heart rate.