Heart Flashcards
What structures are considered to be part of the cardiac conduction system?
SA node, AV node, Purkinje fibers
What layer lines the inner chamber of the heart?
Endocardium
The blunt inferior point tip of the heart is known as what?
Apex
What are the three layers of the heart wall, from deep to superficial?
Endocardium, myocardium, epicardium
What is the volume of blood ejected by each ventricle in one minute called?
Cardiac output
What is the volume of blood ejected by a ventricle in one contraction of the heart?
stroke volume
What are the components of the cardiovascular system?
heart, blood vessels
What is a recording of all nodal and myocardial action potentials in the heart?
ECG
Which side of the heart supplies blood to the pulmonary circuit?
Right
What is the relationship between pressure and volume?
they are inversely proportional
Starting with the superior and inferior venae cavae, list the chambers of the heart in the order which the blood would flow
1: Right atrium
2: Right ventricle
3: Left atrium
4: Left ventricle
The inferior chambers of the heart that pump blood to the arteries are called what?
ventricles
What is the study of the heart and its disorders called?
cardiology
what circuit carries blood from the right ventricle to the lungs for gas exchange and returns it to the left atrium of the heart?
pulmonary
Starting with the return of blood to the heart, place the major phases of the cardiac cycle in order
1: Ventricular filling
2: Isovolumetric contraction
3: Ventricular ejection
4: Isovolumetric Relaxation
What is the normal heart rate set by the SA node referred to as?
sinus rhythm
the heartbeat is coordinated by what?
cardiac conduction system
What chemicals can cause increased heart rate?
caffeine, nicotine, thyroid hormone
What term refers to the relaxation of the heart?
diastole
What carries action potentials throughout the ventricular myocardium to excite the ventricles?
purkinje fibers
Which part of the cardiac conduction system acts as the pacemaker?
sinoatrial (SA) node
List the events of an action potential in a ventricular cardiocyte in order
1: Voltage-gated Na+ channels open
2: Influx of Na+ causes more Na+ channels to open; depolarization
3: Na+ channels close as membrane potential peaks at +30mV
4: Ca2+ enters through slow calcium channels; creates plateau
5: Ca2+ channels close, K+ channels open; repolarization
What are short, thick, branched muscle cells of the heart?
cardiocytes
What term refers to the contraction of the heart?
systole
Which circuit pumps blood from the left side of the heart to the body tissue?
systemic circuit
The smaller blood vessels on the outside of the heart are what?
inferior vena cava
What are the functions of the fibrous skeleton?
1: Provides electrical insulation between the atria and ventricles;
2: Provides structural support for the heart;
3: Anchors the cardiocytes and give them something to pull against
What branch of the left coronary artery travels down the front of the heart to the apex of the heart?
anterior interventricular
The blood vessel that collects venous drainage from the anterior side of the heart and travels alongside the anterior interventricular artery is what?
The great cardiac vein
Another name for the epicardium is what?
visceral pericardium
A sphygmomanometer is used to measure what?
blood pressure
What is used to measure blood pressure?
sphygmomanometer
What is the ability to rhythmically depolarize without outside stimulation called?
autorhythmic
Which arterial branch usually arises from the right coronary artery and supplies the back wall of the heart, both left and right ventricles?
posterior interventricular branch
Which groove extends downward from the coronary sulcus on the back of the heart?
posterior interventricular sulcus
When the ventricles are relaxed and their pressure is low, which valves are open?
atrioventricular valves
Which valves open when the ventricles contract and eject blood into the aorta and pulmonary trunk?
semilunar valves
Which valves regulate the openings between the atria and ventricles?
atrioventricular
One specific cause of arrhythmia is a failure of the cardiac conduction system to transmit signals, called what?
heart block
Closing the aortic and pulmonary semilunar valves produces which heart sound?
second
The mitral valve is also known as what?
left AV valve
excitation in the cardiac conduction system leaves the AV node by way of what? also known as the bundle of His
AV Bundle
Cardiac muscle relies on what process to produce ATP?
Aerobic respiration
The QRS wave of an ECG represents what of the ventricular myocardium?
depolarization
During which wave of an ECG does the atria depolarize?
P wave
During which wave do ventricles repolarize on an ECG?
T wave
