Lecture 18: Arterial System and Pulse Pressure (Hayward) Flashcards
BP usually measures:
arterial pressure
arterial or venous side has more resistance?
arterial side
Pressure in arterial system is a fx of:
volume in minus volume out
Dicrotic notch
assoc. with sudden release of push from heart; there is initial fast recoil that is very fast, which means there will be a squeeze of blood on arterial system that is greater than what’s leaving at that time
What physiological factors determine arterial pressure?
cardiac output, vascular resistance
What physical factors determine arterial pressure?
blood volume, vessel compliance. We have less control over these
increased vessel compliance –> change in pressure for same volume in?
decreased
increased cardiac output –> MAP at constant TPR?
increases
Increased TPR with constant cardiac output –> MAP?
Increases
Total energy =
= KE + PE = systolic energy
What type of energy is used to move blood forward during diastole?
PE
outflow»_space;>inflow in ________
diastole
inflow > outflow in _______
systole
changes in CO force changes in _____ if TPR remains the same
MAP
pulse pressure =
systolic pressure - diastolic pressure
MAP formulas
MAP = CO * TPR = (HR*SV) * TPR = Pdia + [(Psys - Pdia)/3]
systolic pressure
peak pressure generated when heart pumps blood out to arterial system
Main factors contributing to systolic pressure (3)
1) ventricular stroke volume
2) rate of ejection
3) compliance of aorta
increased SV with all else same–> systolic pressure?
increases (i.e. athlete)
decreased compliance with all else same –> systolic pressure
increases
increased stroke volume –> diastolic pressure
decreases
importance of pulse pressure
tells you how volume is moving through the CV system. Pressure felt when feeling a pulse
hypertension
high resistance in system
aortic insufficiency during diastole –> arterial pressure, pulse pressure?
arterial pressure drops, pulse pressure rises
2 Possible causes of low pulse pressure
1) hemorrhage
2) congestive heart failure (damage to heart tissue)
3 possible causes of high pulse pressure
1) bradycardia (results in slow filling)
2) hypertension
3) decreased aortic compliance
measuring diastolic pressure
point when flow changes from turbulent to laminar flow when pressure cuff released
Normal system vs. pulmonary MAP
systemic: 100mmHg, pulmonary: 10mmHg
