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AN SC 310 - 16

  1. What is the flow rule?
    Flow = change in P divided by R
  2. What is bulk flow?
    Flow due to pressure gradient
  3. How is the pressure gradient calculated?
    Pressure in aorta - pressurein vena cava just before it empties into R atrium
  4. What is the mean arteriole pressure (MAP)?
    90 mm Hg
  5. What is the central venous pressure (CVP)?
    0 mm Hg
  6. What is the pressure gradient of the systemic circuit?
    MAP - CVP = 90 - 0 = 90 mm Hg
  7. What is the pressure gradient of the pulmonary circuit?
    • Pulmonary arteriole pressure = 15 mm Hg
    • Pulmonary venous pressure = 0 mm Hg
    • PAP - PVP = 15 - 0 = 15 mm Hg
  8. What factors affect resistance?
    • Radius
    • Length
    • Viscosity
  9. What is Poiseuille's Law?
    • Flow = (pi)(deltaP)(r4) / 8nL
    • n = viscosity
  10. How do pressure gradients and resistance in systemic circulation relate? (eqn)
    Flow = deltaP/R

    • Flow = cardiac output
    • deltP = mean arterial pressure
    • R = total peripheral resistance

    CO = MAP/TPR
  11. Why are arteries a pressure reservoir?
    • Thick elastic arterial walls
    • Low compliance
    • Expand as blood enters during systole
    • Recoil during diastole
  12. What is compliance?
    Measure of how the pressure of a vessel will change w/ a change in volume

    Low compliance means small increase in vol causes large increase in pressure

    High compliance means lg increase in vol reqd to produce lg increase in pressure
  13. What is arterial blood pressure?
    Pressure in aorta
  14. What vessels regulate resistance?
    Arterioles
  15. What is the pressure drop in arterioles (artery end to cap end)?
    90 to 40 mm Hg
  16. What is organ blood flow?
    Organ blood flow = MAP/organ resistance
  17. How does norepinephrine affect arteriole smooth muscle cells?
    • Binds to alpha adrenergic receptors 
    • Vasoconstriction
  18. How does epinephrine affect arterioles?
    • Binds to alpha and beta2 receptors
    • alpha - vasoconstriction
    • beta2 - vasodilation
  19. How does epinephrine concentratoin affect arteriole radius?
    Lower [] - binds to beta2 = vasodilation

    • Higher [] - binds to alpha and beta2 = vasoconstriction & dilation
    • Vasoconstriction dominant
  20. What are the 3 hormones that control arteriole radius & map? Where do they originate?
    • Epinephrine - adrenal medulla
    • Vasopressin = ADH - posterior pituitary
    • Angiotensin II - synthed from angiotensinogen
Author
ebacker
ID
189084
Card Set
AN SC 310 - 16
Description
Lecture 16 - The Cardiovascular System: Blood Vessels, Blood Flow, and Blood Pressure
Updated

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