Cardio| Hemodynamics

1.03 Hemodynamics. Cardiovacular system reveiw for the USMLE Step 1 exam.   Hemodynamics studies blood flow through the body Volumetric flow rate (Q) describes the volume of material moving through space per unit time, in terms of psychiatry it is the amount of blood moving through a vessel per unit time Volumetric flow rate is proportional to radius to the 4th power, so when radius increases, volumetric flow rate increases Resistance is a measure of a blood vessel's opposition to blood flow Resistance is inversely proportional to radius to the 4th power, so when vessel radius is increased, resistance decreases For vessels in series, you can simply add the resistances of each up to get the total resistance For vessels in parallel, the total resistance is equal to the sum of the inverses of the resistances each vessel