CH 16, 17, 18 Flashcards
SA node is the ____ pacemaker and the __ sound
main pacemaker, S1 sound
AV node is the ____ pacemaker, and the __ sound
backup pacemaker, S2 sound
Arteries of the heart and side
Right Main Arteries
- Right coronary artery (RCA)
- Posterior descending artery (PDA)
Left Main Arteries
- Left Anterior Descending Artery (LAD)
- Circumflex Coronary Artery (CIRC)
Most common place for a heart attack
Left Anterior descending artery (LAD)
__ Na+ pumped __, and __ K+ pumped __
3 Na+ out for every 2 K+ in
Cells internal action potential is ______ charged because the the pump activity creates a net outward current of ____ positive charges
negatively, positive
Atrial Arrhythmias/dysrhythmias originate from where
SA node, Atria, or AV node
S = Ventricular Arrhythmias/dysrhythmias originate from where
Bindle of His, purkinje fibers, or ventricle muscles
Tachycardia ____ cardiac output, particularly when ventricular rate is ___
reduces, great than 160
In tachycardia, stroke volume becomes _____ because of _______ and ______ (____) at high rates of_____
stroke volume is reduced because of decreased ventricular filling time and decreased overall ventricular filling (preload) at high rates of contraction
Preload Definition
volume of blood in the heart at the end of diastole
- the amount of blood in the ventricle after it contracts, as it’s filling
- the volume of blood that enters the right atrium from the venous system
preload factors
those that affect cardiac output but occur before contraction
Afterload is
the amount of resistance that the ventricle must overcome in order to pump blood out of the heart
the greater the _____ _______ ______ _____, the greater the ______ against the ____ ____
systemic arterial vascular resistance, the greater the afterload against the left ventricle
most commonly, afterload describes…
the resistance exerted by the pressure within the aorta against the left ventricle
_____ artery pressure creates ____ ____ for the ____ _____
pulmonary artery pressure creates high afterload for the right ventricle
Stroke Volume is
the amount of blood pumped out or ejected from the left ventricle with each contraction
stroke volume is also referred to as
left ventricular ejection fraction
cardiac output is
the amount of blood that the heart pumps out of the left ventricle each minute
cardiac output is diminished in HF because…
the left ventricle is weakened and cannot adequately pump blood out of the chamber
cardiac contractility is
the ability of the myocardium to stretch and contract in response to the filling of the heart with blood
LVEF stands for
Left ventricular ejection fraction
LVEF is
the volume of blood pumped with each ventricular contraction
Healthy and HF percentages of LVEF
Healthy: 60-70% of blood volume pumped out with each contraction.
HF: <40%
