Hemodynamics & Vasculature Flashcards
Explain the relationship between pressure, flow, and resistance in the circulatory system (Flow Equation), and describe how changes in vascular resistance determine the distribution of cardiac output among tissues.
Flow = Change in Pressure over the vascular resistance
Define how vascular resistance, blood viscosity, vessel length, and vessel radius affect blood flow (Poiseuille’s Law).
As radius increases, you have increased flow, but decreased resistance.
As viscosity increases, flow decreases and resistance increases
As length increases, flow decreases and resistance increases
Explain how the pulsatile flow of blood produced by the heart is converted to steady flow in the capillary beds.
I’m guessing just because of the quality of the vessels, and compliance of said vessels
Define vascular compliance.
Compliance represents the elastic properties of vessels
It absorbs energy and dampens pulsatile flow
Define the relationship between vascular wall tension, transmural pressure, radius, and wall thickness (LaPlace’s Law).
As transmural pressure increases, wall tension increases
As radius increases, tension increases
As thickness increases, the tension decreases
Define Fick’s Principle and describe how it can be used to determine transcapillary efflux.
How much is used. Amount in minues amount out.
Explain how the balance between hydrostatic and oncotic pressure in a capillary bed determines the direction of transcapillary transport (Starling’s Equation).
Hydrostatic pressure is just the blood pressure (transmural pressure), the force driving reabsorption is driven by an osmotic force (primarily proteins in blood)
