Cardiovascular System Flashcards
In the past decade, many people over 70 have completed the Ironman World Championships in Hawaii. In what way might age-related changes of the heart limit the performance of these athletes?
Elderly athletes may be hampered by sclerosis and thickening of heart valve flaps, a decline in cardiac reserve, fibrosis of cardiac muscle and atherosclerosis.
name 2 components of the fetal heart that allow blood to bypass the lungs.
The foramen ovale and the ductus arteriosus both allow blood to bypass the fetal lungs.
What problem of cardiac output might ensue if the heart beats far to rapidly for an extended period, that is if tachycardia occurs? Why?
If the heart is beating very rapidly, the amount of time for ventricular filling between contractions is decreased. This decreases the end diastolic volume, decreases the stroke volume, and therefore decreases the cardiac output.
After running to catch a bus, Josh noticed that his heart was faster than normally and was pounding forcefully in his chest. How did his increased HR and SV come about?
exercise activated the sympathetic nervous system. Sympathetic nervous system activity increases heart rate. It also directly increases ventricular contractility, therby increasing Josh’s stroke volume.
During the cardiac cycle, there are two periods when all four valves are closed. name these two periods.
The periods when all 4 valves are closed are the isovolumeteric contraction phase and the isovolumeteric relaxation phase.
If the mitral valve were insufficient, would you expect to hear the murmur (of blood flowing through the valve that should be closed) during ventricular systole or diastole?
The murmur of mitral insufficiency occurs during ventricular systole (because this is when the valve should be closed, and the murmur is due to blood leaking through the incompletely closed valve into the atrium.
