I cant figure out where my brain is not making the connection. Can anyone help. This is loaded detail with Physio so be forewarned. So I'm trying to "Understand" all this, so it makes sense and its not memorization. Im trying to relate all the equations in Cardio Phys and I seem to keep tripping up on one main thing. Here goes: If ...and it is because Im copying from BRS Physio Cardio Chp 3 equations.... If Velocity of Blood Flow can be expressed by V= Q/A, so Velocity is directly proportional to Blood Flow (Q) and is inversely proportional to the cross sectional area (A) at any level of the cardiovasc system, And Turbulance (non straight blood flow) is INCREASED by 1. DEC blood viscosity, and 2. INC blood Velocity (with the example of narrowed vessels beside it in the book), AND Resistance is Directly proportional to viscosity, and Inversely proportional to the radius (by a power of 4)......by Poiseuilles eq. R= 8nl/ (pie symbol)r^4 Then you get the relationship that Blood Flow (Q) is inversely proportional to Resistance...so it cant make sense for Velocity to be increased if vessel radius is smaller. Now look...I get it in my head ..I can almost hear my old Kaplan MCAT instructor talking about the example of putting your finger on a hose and how much faster the water comes out but the equations dont add up? See below: If Velocity (V) increases w/ small or dec area, and Resistance is proportional to Viscosity, and Inversely prop. to radius, then as radius decreases, resistance increases and velocity increases (bc its inversely prop to surf area), so you think Velocity is proportional to Q (Blood flow) and Q is INVERSELY proportional to resistance, then WAIT!! if you Inc resistance, you decrease Q, and thus Decrease Velocity. I probably just lost all of you in that translation but its not making the connection all the way across so Im getting confused. It makes sens that dec a diameter will inc the velocity of the blood thru it, but that doesnt hold true if you look at the example in the book, where its saying velocity is prop to flow, well flow is inversely prop to resistance which is inversely prop to radius...so DEC radius, Inc Resistance and thus Dec Flow and Thus dec velocity.... So a smaller or narrowing of the vessel CANT inc Velocity. Can anyone help or did I just confuse the masses?