Haemodynamics Flashcards
What is the equation for SV?
SV = EDV - ESV
Central venous pressure affects the passive filling of the ventricles and hence EDV or ESV?
EDV
Aortic pressure affects the ejection of blood from the left ventricle and hence EDV or ESV?
ESV
HR is only influenced by the sympathetic system. True or false?
False - sympathetic and parasympathetic
What is meant by preload?
The volume of blood in the ventricle after diastole (EDV) - the stretch of the ventricular muscle
What is meant by afterload?
The resistance the left ventricle must overcome to circulate blood
What is cardiac output?
The amount of blood pumped out of the heart in a minute
What is stroke volume?
The amount of blood pumped out of the heart per beat
The greater the afterload, the less energy needed for ventricular contraction. True or false?
False - the more energy needed
Arterial pressure is directly proportional to flow resistance of the vascular network. True or false?
True
How can flow resistance be controlled?
By changes in vessel diameter - i.e. constriction/relaxation
Poiseuille’s law describes flow resistance in an entire branch. True or false?
False - an individual vessel or tube
What two things determine blood viscosity?
Haematocrit
Protein content
As protein content and haematocrit levels in blood increase, viscosity increases. True or false?
True
Do longer vessels have more or less resistance than shorter ones?
More resistance