IP 2 WK 14 HTN Definitions

alchemist04's version from 2018-11-25 20:31


Question Answer
Heart rate (HR)number of heart contractions per minute
Stroke volume (SV)volume of blood pumped from a ventricle of the heart in one beat or volume per beat
SV equation =EDV - ESV
Cardiac output (CO)volume of blood ejected per unit of time; CO depend on HR and SV. or volume per time unit
CO equation =HR x SV
Systolic blood pressure (SBP)pressure (measured in mm Hg) in the arterial wall during cardiac contraction or emptying
Diastolic blood pressure (DBP)pressure (measured in mm Hg) in the arterial wall during the filling of the ventricles or relaxation


Question Answer
Mean arterial pressure (MAP)average pressure throughout the cardiac cycle of contraction; Since 2/3 of the time is spent in diastole and 1/3 in systole.
The MAP is estimated using the following equation, MAP =1/3 (SBP) + 2/3 (DBP)
Total peripheral resistance (TPR)sum of the resistance of all of the peripheral vasculature in the systemic circulation
Hypertension (HTN)persistent elevation of arterial blood pressure (BP)
Isolated systolic hypertension (ISH)SBP > 140 mm Hg and DBP < 90 mm Hg
Pulse pressuredifference between SBP and DBP which indicates arterial wall stiffness; higher pulse pressures are correlated with increased risk of cardiovascular morbidity and mortality


Question Answer
atrioventricular valves (AV valves)Tricuspid valve (Right AV valve); Bicuspid valve (Left AV valve)
Semilunar valvesPulmonary valve (right semilunar valve); Aortic valve (left semilunar valve)
desmosomesmechanically hold cells together
gap junctionselectrically couple adjacent cells, allowing action potentials to spread from one cell to adjacent cells


Question Answer
Depolarization of Cardia musclesNa+ influx
PlateauK+ flows out via K+ channel; Ca2+ slowly moves in via Ca2+ channel
RepolarizationK+ continues to flow out via K+ channel; Ca2+ channel close
Explain Action potential of pacemaker(1) Na+ channels opens (Na+ influx) causing slow depolarization (2) Ca2+ Channel opens and Ca2+ influx (causing fast depolarization and Action Potential); (3) the AP reaches 0 mv and the Ca2+ closes while K+ channel opens, K+ moves out (repolarization occurs)
Components of Intrinsic conduction system(1) SinoAtrial node (SA node); (2) AtroVentriculal node (AV node); (3) Bundle of HIs and (4) Purkinji fiber


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SystoleCardiac contraction or emptying
DiastoleCardiac relaxation or filling
Ventricular diastolefilling or relaxation of ventricle
During the ventricular diastole, what happen to the SA node membrane potentialThe SA node reaches threshold and fires action potential
EDVEnd Diastole Volume, it is the volume of blood in the ventricle by the end of diastole
What phase does EDV occursPhase 1


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At what phase does ventricular injection peaks?Phase 2, during the ventricular systole
ESVEnd Systolic Volume; the volume of the blood remaining in the ventricle after contraction or at the beginning of diastole (relaxation or filling)
What is the relationship btw SV, EDV and ESV?SV = EDV - ESV
At what phase does ESV occurs?Phase 3
At what phase does Ventricular systole occurs?Phase 2
Ventricular systoleContraction of ventricle or ejection of blood from ventricle


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What is Isovolumetric relaxationthe time when the ventricle relax and for a brief moment ventricular pressure dramatically drops and blood pressure in all aorta and pulmonary artery forces the semilunar valves closed
What phase is isovolumetric relaxation?Phase 3
What phase is Isovolumetric contraction?Phase 2
What phase is atrial contraction?Phase 1
PreloadIt is the pressure in the ventricles just before they contract