TOPIC 8 Flashcards
right side of the heart has
deoxygenated blood
left side of the heart has
oxygenated blood
What are early signs of hypoxia?
Restlessness, headache, fatigue, SOB.
the ventricles ____ with blood during diastole
fill
the ventricles ______ with blood during systole
empty
stroke volume
The volume of blood ejected from the ventricles during systole
sterlings law
As the myocardium stretches, the strength of the subsequent contraction increases
S1 heart sound “Lub”
mitral and tricuspid valves close
s2 heart sound “dub”
aortic and pulmonic close
cardiac output
The volume of blood ejected from the left ventricle each minute.
what is normal cardiac output
4 to 6 L/min
stroke volume
Amount of blood ejected from the left ventricle with each contraction
Cardiac output equation
CO = HR(heart rate) x S(stroke volume)
the circulating blood volume changes according to the….
oxygen and metabolic needs of the body
preload
The amount of blood in the left ventricle at the end of diastole, often referred to as end-diastolic volume.
afterload
Resistance to left ventricular ejection
myocardial contractility
The ability of the heart muscle to contract.
what can affect myocardial contractility
o Injury to the myocardial muscle such as an acute MI causes a decrease in myocardial contractility.
o The myocardium of the older adult is stiffer with a slower ventricular filling rate and prolonged contraction time.
where should electrical impulses originate from
SA node (if they don’t start in the SA node it can cause conduction disturbances)
dysrhythmias
Rhythm disturbances, meaning a deviation from the normal sinus heart rhythm
tachycardia
greater than 100 bpm (fast HR)
bradycardia
less than 60 bpm (slow HR)
Tachydysrhythmias and bradydysrhythmias lower…
cardiac output and blood pressure.
atrial fibrillation
rapid, random, ineffective contractions of the atrium “quivering”