Cardiac Function Part 2: Hemodynamics Flashcards
how much of blood is in systemic circulation?
84%
majority in veins, then arteries, then arterioles & capillaries
what is the major volume reservoir?
systemic veins: where you store extra blood
how do systemic veins act as the major volume reservoir?
- easily expand and contract to meet demands
- high compliance compared to arteries which are less compliant
what is the major pressure reservoir?
systemic arteries:
- preserve pressure to propel blood
- low compliance
what has higher compliance, veins or arteries?
veins have higher compliance
Q
blood flow
R
resistance
P
pressure
fluid equation
Δ P = Q X R
resistance equation
R = ΔP / Q
T/F: the heart is a constant pressure (MAP) generator
true
how variable are Q and R?
if ΔP = Q x R, Q and R must vary considerably depending on circumstance, tissue needs, etc in order to maintain constant pressure
blood flow through a vessel depends on
the pressure difference/gradient: force pushing blood through
this is nOT the same as absolute pressure! need a pressure difference
cardiac output is the same thing as blood ______
flow
how is flow measured?
displacement of volume (mL or cm3) per unit time (min or sec)
not the same as velocity! that is distance/time
what can increase blood flow turbulence and likely cause a murmur in dogs?
