Cardiovascular Control Flashcards
Cardiac output is equal to
A. Product of heart rate and stroke volume
B. Difference between end diastolic and end systolic volume
C. Product of heart rate and blood pressure
D. Product of heart rate and pulse pressure
E. Product of stroke volume and blood pressure
A
According to the Frank-Starling law, cardiac output is directly related to: A. End systolic volume B. Heart rate C. Venous return D. Size of ventricle E. Size of Atrium
C (Increased End Diastolic Volume influences Venous return)
How does the activation of the parasympathetic nervous system affect
cardiac output (CO)?
A. Decrease CO by reducing heart rate
B. Decrease CO by reducing cardiac contractility
C. Decrease CO by reducing venous return
D. Decrease CO by increasing venous return
E. Increase CO by increasing heart rate
A
How does parasympathetic nervous system decrease heart rate? A. By increasing permeability to Ca2+ B. By increasing permeability to K+ C. By activating adrenoreceptors D. By increasing Na+ entry to the cell E. By increasing permeability to H+
B Allowing K to enter the cell, reducing sensitivity
Activation of the sympathetic nervous system causes all of the following EXCEPT A. Increased heart rate B. Increased venous return C. Constriction of systemic veins D. Increased cardiac contractility E. Decreased venous return
E SNS increases venous return by vasoconstriction
Jonathan Has atherosclerosis. Explain why he would have decreased cardiac output using concept of afterload and stroke volume.
Plaque build-up from atherosclerosis would increase the resistance of the systemic circuit and thus increase afterload.
An increase in afterload results in a smaller stroke volume. (due to increased end systolic volume)
Reduced stroke volume would thus reduce the cardiac output proportionally.
Emily Jones, 35, attends clinic for checkup, has a HR of 80 bpm and an EDV (end diastolic volume) of 160mL and an ESV (end systolic volume) of 40mL
What is her stroke volume?
What is her cardiac output?
- stroke volume = 160-40 = 120mL/Beat
2. Cardiac Output = 120 * 80 = 9600mL/min
Jithin, 52, suffering from heart failure. Answer question below to determine cause.
What is the pathway of the blood through the heart?
Blood is pooling in the lungs, what part of heart is failing?
What does absence of QRS complex in ECG indicate?
- blood reaches right atrium from superior and inferior vena cava
- Blood is pumped through tricuspid valve into right atrium
- Blood is pumped from right atrium through pulmonary semilunar valve into the pulmonary trunk (pulmonary circuit)
- Oxygenated blood is received by pulmonary veins
- Oxygenated blood is pumped from left atrium into left ventricle via bicuspid (mitral) valve
- Blood is pumped from ventricle into systemic circulation via the aortic semilunar valve
Left side of the heart is not functioning correctly
Absence of QRS indicates no systolic function of the ventricle. (in this case the left)
Jithin has a heart transplant. Doc notes the heart continues to beat after it was removed from thorax, why is it able to beat after it is removed?
The auto rhythmic cells (SA node) are separate from autonomic nervous system and generate their own action potential due to unstable resting potential
- Match description of cardiac cycle with the titles below:
Atrial and Ventricular diastole, isovolumetric ventricular relaxation, Ventricular ejection, atrial systole, isovolumetric ventricular contraction
Place events in order
Add electrical events of cardiac cycle (electrical events precede corresponding mechanical event)
isovolumetric ventricular relaxation, Atrial diastole, atrial systole, ventricular diastole, isovolumetric ventricular contraction, ventricular ejection,
Pwave results in atrial systole
QRS wave results in ventricle systole
T wave results in repolarization of ventricles
