Cardiovascular System (Test 2) Flashcards
Where is the bicuspid or mitral valve located?
between the left atrium and the left ventricle
What is ECG (electrocardiogram)?
An ECG is a graphic illustration of the Cardiac conduction system.
What causes the P wave in an ECG pattern?
Depolarization of atrial muscle fibers
In the ECG, during which wave does ventricular repolarization occur?
T wave
Can ECG be useful for determining a patient’s cardiac output stroke volume heart sounds end-diastolic volume?
No. ECG would be useful for determining the heart rate
What is most responsible for the plateau of cardiac action potential?
Both calcium and potassium channels
Which cells have pacemaker potential?
The sino-atrial nodal cells have the pacemaker potential.
What determines the cardiac output?
Stroke volume multiplied by heart rate
What is the ratio of stroke volume and end-diastolic volume?
Ejection fraction
What are some indices of ventricular performance?
stroke volume, stroke work, cardiac output, cardiac work
What is the most important factor in influencing the amount of blood pumped by the ventricle?
Venous return
Which two great vessels bring deoxygenated blood back to the heart?
The superior and inferior venae cavae.
When does the first heart sound occur?
The first heart sound occurs during the phase of isovolumetric contraction.
What is the correct sequence for the path of the cardiac impulse?
S-A node, A-V node, bundle of His, Purkinje fibers.
Where does the bundle of His and its branches located?
The bundle of His and its branches is located in the interventricular septum
What are most responsible for phase 0 of a cardiac action potential?
Sodium channels
What events cause cardiacmyocyte repolarization?
Calcium channels begin to close while more potassium channels open; potassium rapidly leaves the cell
What relationship is defined by Frank-Starling’s law of the heart?
End–diastolic volume and stroke volume
The opening of which channel in the autorhythmic cell (pace maker cells) is responsible for the huge positive spike in membrane potential?
L-type calcium channel
What is the typical stroke volume for an adult at rest?
70 (or 80) mL.
Which two heart chambers pump oxygenated blood?
The left atrium and the left ventricle
When does the atrial systole occur?
Towards the end of ventricular diastole
Due to what event does the second heart sound occur?
Closing of the semilunar valves
What does the heart rate dependent on?
Rate of pacemaker potential
Which structure has the slowest conduction velocity of the cardiac impulse?
AV nodal fibers
What is the correct sequence for the blood flow in the heart?
Right heart, tricuspid valve, right ventricle, pulmonic valve, pulmonary circulation, left atria, mitral valve, left ventricle, aortic valve, aorta