Vascular System

  1. Pressure gradient ______ over distance due to _______ friction.
    • Decreases
    • Friction
  2. Poiseuille's Law Formulas
    F= DeltaPr4(n)

    • Resistance __ Ln
    •               _______
    •                  r4

    • F=  DeltaP
    •      ________
    •          R
  3. What is pressure measured in?
    Does water compress well?
    • mm, Hg , or torr
    • No
  4. Velocity of flow definition
    Velocity of flow equation
    Distance a fixed volume of blood will travel in a given period of time.

    V= flow rate/cross-section area
  5. Smooth muscles depend on __ for contraction and depolarization.
  6. Aorta is __cm in diameter and contains about _____ of the total blood.
    • 2.5cm
    • 15-20%
  7. Resistance in __________ circulation is __x great as in ________ circulation.
    • Systemic Circulation
    • 3x
    • Pulmonary Circulation
  8. As pressure goes up the ______ walls expand.
    Diameter of aorta increases __%
    • Arterial
    • 6
  9. Compliance definition
    Compliance Formula
    Amount of expansion or how easily the vessel is stretched.

    C= DeltaVolume/DeltaPressure
  10. Average speed in aorta is ___cm/sec
  11. Average pressure in systemic circulation
    • Systole = 120mm Hg ;
    • Diastole = 80mm Hg
  12. What is the difference between diastolic and systolic pressure called?
    What are 2 things that will increase the pulse pressure?

    Whhen pulse pressure decreases it causes one to faint
    Called pulse Pressue

  13. MAP Stands For?
    What is the average MAP?

    What is the equation for MAP?
    • Mean Arterial Pressure
    • 90-100 mm Hg

    MAP= DIastolic Pressure + 1/3 Pulse Pressure
  14. Review MAP equations
  15. What is MAP affected by?
  16. Intrinsic Regulation of blood flow
    What happens with stretching of arteries walls?
    Vasodilation of arteries is stimulated locally by?

    ____ is excreted from ________ cells in response to mechanical ______ stress, causing ______.
    • Stimulates Vasoconstriction
    • Stimulated locally by ^Adenosine ^CO2 ^K+ and vO2 vpH

    NO / Endothelium / Shear / Vasodilation

  17. ____ is excreted from ________ cells in response to mechanical ______ stress, causing ______.
    NO / Endothelium / Shear / Vasodilation
  18. Extrensic Regulation of blood flow is done so by ______ and ____ _______

    What have a fast response, are tonically active and at regular pressure, continuously sending signals into brain?
    Where are these located?
    • ANS / Endocrine System
    • Barroreceptors located in carotid sinus and aorta tie into the ANS.
  19. Barroreceptors
  20. Calcium channel blockers:
    blocks both smooth and cardiac calcium channels
  21. What is major factor in determining mean arterial pressure?

    MAP Equation =

    MAP in arterioles = ~__ - __mm Hg
    • Arterioles
    • CO x Total Peripheral Pressure

    35-37 (drops from 90 mm Hg)

    Forgan = MAP/Rorgan
  22. What are known as resistance vessels
  23. Review Resistance Formulas:
  24. What in individual organs are responsible for determining how much perfusion (blood flow) the organ receives.
  25. All organs receive the same amount of blood from ________
  26. ________ contain smooth muscle which controls radii.
  27. ________ are close to capillaries and can be controlled locally without having the brain involved.
  28. Vasodilation ___________ radius
  29. Vasodconstriction ___________ radius
  30. Myogenic tone or autoregulation.
    What happens?
    • 1. Smooth muscle conracts
    • 2. Stretch receptors open Ca Channels
    • 3. Vasodilation or vasoconstriction
  31. Metabolic Local Controls is....

    Active Hyperemia:Causes.....
    Results in.....
    Are hormones used in active hyperemia?
    Occurs commonly in?
    Autoregulation that results from the chemical environment created by its own metabolism.

    Active Hyperemia:increased cellular metabolic activity causes an increase in CO2, H+, Adenosine, K+, Osmolarity, Eicosanoids, and bradykinin, NO, and decrease in O2.


    Occurs commonly in Skeletal muscle when excercising.
  32. WHat is AUtoregulation?
  33. What are the three Metabolic local controls?
    • Active Hyperemia
    • Pressure or flow autoregulation
    • Reactive Hyperemia
  34. Pressure or flow autoregulation -

    when pressure changes in arteries.....
    When pressure changes in arteries, the arterioles change their diameter consistent with keeping their organ well perfused.

    may be the same reaction to metabolities and gas concentration as in active hyperemia.

    myogenic responses also in play - increased stretch stimulates contraction.
  35. reactive hyperemia - when a vessel is occluded..........
    reactive hyperemia - when a vessel is occluded and then the occlusion is removed, much blood flows into the organ through wide open arterioles 1. extreme pressure or flow autoregulation2. due to the accumulation of metabolites
  36. Other local substances can also affect diameter of arterioles
    • Paracrines
    •          histamine
    •          endothelin-1 (ET-1)
    •          NO (nitric oxide) - vasodilation

    2. prostaglandins - eicosanoids may increase or decrease arteriole diameter

    prostacyclin PGI2 causes vasodilation – released by endothelial cells

    • b. thromboxane A2 causes vasoconstriction
    • 3. serotonin – vasoconstriction

    Tissue injury stimulates vessels to dilate to get more blood to damaged area
  37. NO (nitric oxide) - vasodilation

    things stimulate its release from endothelial cells
    bradykinin stimulates NO release
    the more shear on the walls, the more NO
    parasympathetic stimulation
    endothelial cells release this all the time to cause basal vasodilation
Card Set
Vascular System
Vascular System