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74 Cards in this Set
- Front
- Back
What is a systole? |
A contraction |
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What is a diastole? |
Relaxation |
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What is the cardiac cycle? |
Blood flow through heart during one complete heartbeat. Atrial systole/diastole followed by ventricular systole/diastole. |
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What is ventricular filling? |
Takes place mid to late diastole. AV valves are open; pressure is low. 80% blood passively flows into ventricles, 20% delivered by atrial systole. |
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What is EDV (end diastolic volume)? |
Volume of blood in each ventricle at end of ventricular diastole |
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What is ventricular systole? |
Atria relaxes and ventricles contract. Rising ventricular pressure-closing of AV valves. |
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What is the isometric contraction phase? |
When all valves are closed |
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What happens during the ejection phase of cardiac cycle? |
Ventricular pressure exceeds pressure in large arteries, forcing SL (semilunar) valves open |
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What is ESV (end systolic volume)? |
Volume of blood remaining in each ventricle after systole |
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What is isovolumetric relaxation? |
Early diastole. Ventricles relax, atria relaxed and filling. Backflow of blood in aorta and pulmonary trunk closes SL valves. |
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What is a diacritic notch? |
Brief rise in aortic pressure as blood rebounds off closed valve |
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What happens to blood pressure (diastole/systole) in any chamber? |
Rises during systole Falls during diastole |
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What happens to blood pressure (diastole/systole) in any chamber? |
Rises during systole Falls during diastole |
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Blood flows from _______ to ______ pressure |
High to low |
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What is an S1 heart sound? |
Loud sounds produced by AV valves |
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What is an S1 heart sound? |
Loud sounds produced by AV valves |
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What is an S2 heart sound? |
Loud sounds produced by semilunar valves |
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What is an S1 heart sound? |
Loud sounds produced by AV valves |
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What is an S2 heart sound? |
Loud sounds produced by semilunar valves |
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What are S3 and S4 heart sounds? |
Soft sounds, blood flows into ventricles and atrial contraction |
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What is a heart murmur? |
Sounds produced by regurgitation through valves |
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What is cardiodynamics? |
Movement and force generated by cardiac contractions. |
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What is cardiodynamics? |
Movement and force generated by cardiac contractions. |
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Cardiodynamics |
EDV, ESV, SV (EDV-ESV), ejection fraction (% of EDV represented by SV) |
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What is cardiodynamics? |
Movement and force generated by cardiac contractions. |
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Cardiodynamics |
EDV, ESV, SV (EDV-ESV), ejection fraction (% of EDV represented by SV) |
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What is cardiac output? |
Volume pumped by left ventricle in one minute. CO=HR*SV HR (heart rate) SV (stroke volume) |
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Factors affecting Cardiac Output |
Cardiac output, heart rate, stroke volume. CO: adjusted by changes in HR or SV HR: adjusted by autonomic nervous system or hormones SV: adjusted by changing EDV or ESV. |
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What is autonomic innervation? |
Sympathetic and parasympathetic fibers from the medulla oblongata (cardiac centers) affect heart rate |
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Cardiac centers adjust cardiac activity depending on _____ |
The demands of body tissues |
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What is autonomic tone? |
Dual innervation maintains resting time by releasing ACh and NE |
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What is autonomic tone? |
Dual innervation maintains resting time by releasing ACh and NE |
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What do cardiac centers monitor? |
BP using baroreceptors, arterial oxygen and carbon dioxide levels using chemoreceptors. |
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Sympathetic neurons ______ heart rate and parasympathetic neurons _______ heart rate. |
Increase, slow |
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What happens during rising ventricular pressure? |
The AV valve closes |
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When atrial pressure exceeds ventricular pressure, what happens? |
AV valves open and you begin at ventricular filling. |
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What do vasodilators and vasoconstrictors affect? |
Afterloadon heart, Peripheralblood pressure, Capillaryblood flow |
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What are resistance vessels? |
arterioles |
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What is resistance? |
opposition to blood flow |
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Where do arteries carry blood? |
away from the heart |
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What are capillaries? |
they are the smallest blood vessels, location of exchange between blood and interstitial fluid |
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What is the capillary function? |
location of exchange functions of cardiovascular system, materials diffuse between blood and interstitial fluid. |
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What are capillary beds? |
connect one arteriole and one venule |
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What is the precapillary sphincter? |
guards entrance to each capillary, opens and closes causing capillary blood to flow in pulses. |
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What is arterial anastomosis? |
fusion of two collateral arteries |
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What is arteriovenous anastomoses? |
direct connections between arterioles and venules, bypass capillary bed. |
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What is vasomotion? |
contraction and relaxation cycle of capillary sphincters, causes blood flow in capillary beds to constantly change routes |
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What do veins do? |
collect blood from capillaries in tissues and organs, return blood to heart, have lower BP. |
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What are venous valves? |
prevent blood from flowing backward |
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Where do you find most of the blood? |
in the veins (venous system)-about 60 to 65% |
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What is venoconstriction? |
systemic veins constrict |
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Total capillary blood flow equals ______- |
cardiac output |
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Total capillary blood flow is determined by: |
pressure and resistance in the cardiovascular system |
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What is pressure? |
heart generates P to overcome reistance, absolute pressure is less important than pressure gradient |
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What is the pressure gradient (deltaP)? |
difference in pressure from one end of the vessel to the other |
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What is flow? |
proportional to the pressure difference, divided by R |
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How do you measure venous pressure? |
By pressure in the venous system |
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Circulatory pressure must overcome _______________ of entire cardiovascular system |
total peripheral resistance (R) |
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What is total peripheral resistance? |
vascular resistance, blood viscosity, and turbulence |
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What is vascular resistance? |
due to friction b/w blood and vessel walls |
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What does vascular resistance depend on? |
vessel length and vessel diameter Adult vessel length is constant |
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What does vessel diameter vary by? |
vasodilation and vasoconstriction |
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What is viscosity? |
total peripheral resistance caused by molecules and suspended materials in a liquid |
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What is turbulence? |
swirling action that disturbs smooth flow of liquid, occurs in heart chambers and great vessels |
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What is systolic pressure? |
peak arterial pressure during ventricular systole |
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What is diastolic pressure? |
minimum arterial pressure during diastole |
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What is MAP? |
diastolic pressure + 1/3 pulse pressure |
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What is pulse pressure? |
difference b/w systolic pressure and diastolic pressure |
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What happens to arterial walls during elastic rebound? |
stretch during systole, rebound during diastole, keep blood moving during diastole |
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Venous system has ____ effective BP |
low |
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What is venous pressure and return? |
determines amount of blood arriving at right atrium each minute |
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What is the respiratory pump? |
inhaling decreases thoracic pressure and increases venous return, exhaling raised thoracic pressure and decreases venous return |
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What is diffusion? |
movement of ions or molecules from high to low concentration against the concentration gradient |
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What is the result of osmosis? |
reabsorption |