conduction system of the heart Flashcards
what is the conduction system of the heart ?
nerve like cardiac cells that send electrical impulses to contract heart
what are the 2 types of cardiac muscle cells
myocardial contractile cells and myocardial conducting cells
what are myocardial contractile cells responsible for ?
contractions that pump blood
what are myocardial conducting cells responsible for ?
initiating the electrical impulse that triggers muscle contraction
what is the SA node called ?
the pacemaker of the heart
what does the SA node do ?
causes both atria to contract, forcing blood into the ventricles
what does the AV node do ?
sends an impulse to the AV bundle to finish contacting
Where are the bundle branches located ?
the interventricular septum
which bundle branch is thicker ?
the left (because the left ventricle is thicker)
where do the bundle branches reach ?
the apex to connect to purkinje fibers
What do purkinje fibers do ?
spread an electrical impulse all throughout the myocardium causing ventrical contraction
what is a normal resting heart rate ?
60-100 beats per minute
what is it called when your heart rate is below 60 bpm ?
bradycardium
what is it called when your heart rate is above 100 bpm ?
tachycardium
what is it called when you have an irregular heartbeat ?
arrhythmia
if your arrhythmia becomes a serious problem, what can be done ?
you can get an artificial pacemaker implanted
what is an artificial pacemaker ?
delivers electric impulses to the myocardium to make sure the heart is contracting enough to pump blood.
what is an electrocardiogram ?
it checks electrical changes seen in heart activity
what is an electrocardiogram used for ?
to reveal normal or abnormal heart function
what does a P wave represent ?
atrial contraction
what does the QRS represent ?
the ventricles contracting as the atria relaxes.
what does the T wave represent ?
the ventricles relaxing
what does a large P wave indicate ?
an enlarged atrium or valves that do not work
what does a large Q wave represent ?
can be a sign of heart attack
what does a suppressed or inverted Q wave indicate ?
an enlarged ventricle
what can a large R wave indicate ?
an enlarged ventricle
