Lecture 17: Hemodynamics (Hayward) Flashcards
which vessels have large elastic layer? why?
Arteries. Stores energy so you can continuously push blood through CV when heart is not actively pushing it through
Flow formula
F = (P1-P2)/R Q=F=Flow
Cardiac output formula
CO = (MAP-RAP)/TPR TPR = resistance in entire vascular tree ***MEMORIZE
Sickle cell anemia
fibrinogen in RBCs increases, decreasing their flexibility and results in disturbances in regional blood flow
increasing radius of tubes–> TPR
decreases
Increasing number of tubes in parallel –> TPR
decreases
Increasing tube length –> TPR
increases
Poiseuille’s Law
describes effect of length, radius, number of tubes, etc. effect resistance
Tubes in parallel generally have _____ resistance to tubes in series
lower
MAP formula**
MAP = CO * TPR
velocity def. and formula
distance a fluid travels per unit time. V=Q/A
increased cross-sectional area –> velocity
decreases
in laminar flow shear stress on vascular walls is prop. to
rate of flow
ONLY place where energy can be added to vasculature
heart
2 components of total energy stored in vasculature
1) KE (forward projecting)
2) PE (lateral projecting)
anemia –> turbulent flow
increases
Reynold’s number
predicts turbulence. Re=VDdensity/viscosity
high blood velocity –> turbulent flow
increases
larger vessel size –> turbulent flow
increases
Bernoulli’s Principle
total energy at one area in a closed system must equal total energy in another area. Achieved by Pressure/volume/area/velocity relationships
velocity ______ as venous blood comes out of capillaries and heads back to heart
increases (but at a lower velocity than it left heart)
aortic stenosis –> lateral pressure
decreases
aortic stenosis –> coronary filling
decreases. Harder time getting blood out and storing energy
aneurysm
abnormal dilation of blood vessel walls resulting from disease of the vessel wall. weak vessel wall
aneurysm –> pressure on vessel wall
increases (due to increased vessel diameter)
