according to this one source, cardiac output (vascular) = blood flow (http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/APIINotes5 cardiac_equations.htm) However, their equations do not match: Cardiac output (CO)= Stroke volume * Heart Rate Blood Flow = cross sec area of vessel times velocity This is important because cardiac output is also in relationship with blood pressure: change in bP = cardiac output times resistance of vessel If blood flow equals cardiac output then the equation of blood pressure would also be impacted by blood flow. The statement that started my curiosity was that one way of regulating bP is with vasoconstriction which leads to an increase in peripheral resistance and a lower BLOOD FLOW. Ultimately, this is a mechanism for bP to be increased, however if the lower blood flow also has an effect on blood pressure then it becomes more complicated. So, I want to make sure that blood pressure is not impacted by blood flow. Also, the sympathetic nervous system leads to vasoconstriction of vessels and leads to an increase in bP. But, when you are exercising wouldn't vasoconstriction decrease the amount of blood flowing and thus decrease the oxygen supplying rate to muscles? Thanks for your help.