Cardiac dynamics Flashcards
What is stroke volume?
The volume of blood pumped out of the heart per beat.
Stroke volume usually refers to what part of the heart?
The left ventricle and how much blood is ejected from it.
What is the average stroke volume?
75ml
Stroke volume is determined by several factors what are they?
Venous return
Elasticity of cardiac fibres
The contractility of cardiac tissue.
What is venous return?
The volume of blood returning to the right atrium.
An increase in venous return = an increase in stroke volume. Why is this?
There is more blood available to be pumped.
What is the elasticity of cardiac fibres?
The degree of stretch of cardiac tissue just prior to contraction.
If the strength of the cardiac fibres increases, what also increase?
The force of contraction
What causes and increase in the strength of contraction of the heart?
An increase in contractility of the cardiac tissue.
What does heart rate represent?
The number of complete cardiac cycles, and therefore the number of times the left ventricle ejects blood per minute.
What is the average heart rate?
60-80 BPM
What is your pulse rate?
The measure of the heart rate by palpating radial and carotid arteries
What is the cardiac output?
The volume of blood pumped out of the heart from the left ventricle per minute.
What is the equation to calculate cardiac output?
Q = SV x HR
