Lecture 16: Cardiovascular System 2 Flashcards
What is the cardiac cycle (brief)?
the sequence of mechanical and electrical events repeating with every heartbeat
What kind of pump is the heart?
A two stroke pump
What are the phases of the heart?
The filling phase and the emptying phase
What determines the duration of a cardiac cycle?
An electrical pacemaker in the sinoatrial node
Describe what the right atria recieves.
deoxygenated blood from vena cava
Describe what the left atrium recieves.
Oxygenated blood from the pulmonary vein
What are the atria?
passive reservoirs that contact to force blood into ventricles
What permits unidirectional flow?
AV valves
How are cardiac valves opened and closed?
passively by pressure
What happens when the cardiac valves are not functioning properly?
blood flows backwards (e.g. into
atrium) and flow makes a sound (murmur)
What is a regurgitant lesion?
a lesion that causes the heart valve to not close properly
What is a stenotic lesion?
a valve opening is narrowed which restricts blood flow through it
What is systole?
When ventricles are contracting
What is diastole?
When ventricles are relaxing
At rest, systole is about ___ time, diastole is ___ time
At rest, systole is about 1/3 time, diastole is 2/3 time
At exercise, _____ is
more prominent,
____ is reduced
At exercise, systole is
more prominent,
diastole is reduced
What are the two phases of blood flow?
filling and emptying
What is the systolic arterial pressure?
120 mmHg
What is the diastolic arterial pressure?
80 mmHg
What is pulse pressure?
The difference between systolic and diastolic
What does blood pressure depend on?
cardiac output (total blood flow) and venous return to the heart (preload)
What is the cardiac output?
Volume of blood ejected from the heart every
minute
What is the venous return to heart?
Flow of blood delivered by the heart, contributes to blood pressure
Where do the right and left coronary arteries originate at?
the root of the aorta
