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71 Cards in this Set
- Front
- Back
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Cardiac Cycle |
The sequence of events that occurs during one heartbeat |
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Systole |
Contraction of the heart muscle |
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Myocardium |
heart muscle |
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Diastole |
Relaxation of the myocardium |
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When does the blood fill a chamber? |
Diastole |
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3 stages of Cardiac cycle |
Atrial systole Ventricular systole Diastole |
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0.8 seconds |
duration of the cardiac cycle |
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0.4 seconds |
all chambers rest for... |
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At the end of atrial systole, the ventricles contract; this is called |
Ventricular systole |
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For a brief period during the cardiac cycle, both the atria and the ventricles are in the.....? |
Diastole |
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Contract |
Systole |
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During ____ ______ the atrioventricular (AV) valves are open and the ventricles are relaxed. |
Atrial systole |
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Rest |
Diastole |
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ANS |
Autonomic nervous system |
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plays an important role in coordinating and adapting cardiac function |
Autonomic nervous system (ANS) |
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The Parasympathetic nerve is also called the |
Vagus nerve |
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Sympathetic nerves supply... |
SA node AV node Ventricular myocardium |
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Excess sympathetic activity produces |
"fight-or-flight" response |
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Heart Failure |
This is caused by persistent sympathetic nerve stimulation |
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Tachydysrhythmias |
"fast" rhythm disorders |
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Digoxin |
drugs |
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excess vagal discharge causes |
Drugs |
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"mimic" vagal stimulation is called |
vagomimetic drug |
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Vagomimetic drug is also known as |
parasympathomimetic drugs |
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Two factors that determine cardiac output |
heart rate stroke volume |
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the total blood volume is |
5 L |
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Heart Rate (HR) |
the number of times the heart beats each minute |
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Cardiac output |
the amount of blood pumped by each ventricle in 1 minute |
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Normal adult resting heart rate |
60 and 100 beats/min, average 72 beats/min |
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Reasons for resting heart rates to differ |
Size Gender Age Exercise Stimulation of the autonomic nerves Pathology Hormonal influence Medications |
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Stroke volume |
the second factor affecting cardiac output |
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Stroke volume |
the amount of blood pumped by the ventricle per beat |
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average resting stroke volume |
60 to 80 ml/ beat |
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the greater force of contraction can____ |
increase stroke volume |
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The degree of stretch of the myocardial fibers. The greater the stretch, the stronger the force of contraction |
Starlings law of the heart |
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Allows the heart to pump out the same amount of blood it receives. |
The purpose of Starlings law of the heart |
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inotropic effect |
Strengthening the force of myocardial contraction without stretching the myocardial fibers |
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Cardiac reserve |
The capacity to increase cardiac output above the resting cardiac output |
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EDV |
End-Diastolic Volume |
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End-Diastolic Volume |
The amount of blood in the ventricle at the end of its resting phase (diastole) |
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This determines how much the ventricle is stretched and is the basis of Starlings law of the heart |
EDV |
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the amount of blood in the ventricles at the end of diastole; this is the same as the EDV |
preload |
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ejection fraction |
percentage of the EDV that is pumped |
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when the ventricle contracts, it pumps __% of its volume (EDV) |
67 |
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Refers to resistance or opposition to the flow of blood |
Afterload |
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the pressure that is resistance or the afterload |
aortic blood |
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inotropic effect |
a change in the myocardial contraction that is not caused by stretch |
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positive inotropic effect |
an increase in contractile force |
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negative inotropic effect |
a decrease in contractile force |
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sympathetic nerve stimulation and hormones such as epinephrine and norepinephrine cause what? |
a positive inotropic effect |
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chronotropic effect |
a change in heart rate |
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positive chronotropic effect |
anything that increases heart rate |
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sympathetic nerve stimulation |
causes a positive chronotropic effect |
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vagal (parasympathetic) stimulation |
causes a negative chronotropic effect |
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a change in speed at which the cardiac impulse travels from the SA node through the AV node and the His-Purkinje system |
dromotropic effect |
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Beta1-Adrenergic Receptor Activation |
sympathomimetic effect |
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Beta1-Adrenergic Receptor Blockade |
parasympathetic effect |
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receptors for ACh are called.... |
muscarinic receptors |
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ACh is secreted by a cholinergic fiber, a muscarinic agonist is also called... |
a cholinergic agonist |
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antimuscarinic agent, a cholinergic blocker, or a anticholinergic agent |
a muscarinic blocker is also called... |
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pumps blood to the lungs for oxygenation |
right ventricle |
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pumps blood into the arota for distribution to the systemic circulation |
left ventricle |
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blood backs up in the lungs and heart is unable to pump a sufficient amount of blood to the systemic circulation |
left heart failure |
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pulmonary edema (PE) |
accumulation of fluid within the lungs |
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backward failure |
the backup of blood behind the failed ventricle |
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left ventricular hypertrophy |
increased blood pressure overworks the heart, eventually causing the left ventricle to enlarge and fail |
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hepatomegaly |
enlarged liver |
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splenomegaly |
enlarged spleen |
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JVD |
jugular vein distention |
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when the veins in the neck pulsate and is visible |
JVD |
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stages of the cardiac cycle |
Atrial systole Ventricular systole Diastole |
