Exam 1 extra stuff Flashcards
convective transport
movement of blood around body so diffusion can occur over short distances (einstein principle)
flow equation (two of them)
Q=VA
Q=deltaP/R
What is anomolous viscosity?
blood viscosity depends on blood velocity (increasing viscosity decreases velocity)
What is Pouseilles equation?
All the things that influence magnitude of blood flow:
Q=(πdPr^4)/(8L*viscosity)
various segments of blood vessels (aorta, arteries, arterioles) are arranged in _______
series
Rtotal is summation
within each segment of blood vessels (arterioles) are arranged in _____
parallel
1/Rtot=1/R1+1/R2….
means that more vessels in parallel DECREASES resistance
MBP equation
MBP=COxTPR
force of flowing blood on endothelial cells
shear stress
law of laplace
force of wall on structure - force that makes structure open up
wall tension T=Pxr
wall stress: sigma = Pxr/th
compliance
stretchiness of vessel/structure
C=V/P
atrial systole
in late diastole “atrial kick” where atria contract and force small amount of blood into ventricles. accounts of 15-20% of blood
sequence of events in the heart
atrial systole –> IVC –> rapid ventricular ejection –> reduced ventricular ejection –> IVR –> rapid ventricular filling –> reduced ventricular filling (aka DIASTASIS)
how do sympathetics increase HR?
they speed up phase 4 depolarization and activate funny channels and L type channels
how do parasympathetics slow HR?
they activate K conductance (if there is more K, harder to depolarize)
the primary mechanism for the strenght/rate/duration of the cardiac contraciton is by
changing the amplitude and duration of the Ca2+ transient
calsequestrin
Ca2+ buffering molecule in junctional SR
phospholamban
SR protein that can inhibit SERCA when not phosphorylated - moves off of SERCA when phosphorylated (disinhibition event)
increases rate of decay of Ca2+ transient
what is the effect of PKA phosphorylation of LTCC/PLB?
increase in ca2+ entry/SR release to increase amplitude and decrease duration of Ca transient
what is the effect of TnC phosphorylation?
reduces Ca2+ binding affinity –> Ca2+ unbinds –> increases relaxation rate
what is the effect of RYR phosphorylation?
increases Ca2+ binding affinity by enhancing Ca2+ released from SR
Frank starling relationship
when more blood enters the heart, sarcomere stretch enhances force generating capacity of the muscle. this allows an increase in preload to be matched to increased ejection of blood with each contraction
what are 3 ways to alter preload?
- respiration
- body position
- increases in blood volume (growth, aerobic training, pregnancy)
stroke work equation
SW=VESPxSV
the area of the PV loop
myocardial O2 consumption
MVO2=(arterial O2 content - coronary sinus O2 content) x mean coronary blood flow