Part 1 Flashcards
Sympathetic stimulation of vascular smooth muscle, associated with trauma to that vessel, is associated with ___
vasoconstriction
what statement concerning platelets is false
can divide
the half-life of platelets is 8-12 days; most of the old platelets are removed ___
primarily by macrophage action in the spleen
the major underlying cause of CV disease is ___
ischemia
if you block thromboxane A2, what statement would be true
you will decrease platelet granule release
prostacyclin released from the endothelial cell will block lately function by ___
stimulation of adenyl cyclase activity
in extrinsic pathway of blood coagulation, factor 3, factor 7 and calcium with directly activate ___
factor X
thrombin will ___
convert fibrinogen to fibrin
prothrombin is synthesized by the ___
liver
thrombin will activate ___ which causes more thrombin to be formed
factor V
if calcium was chelated, the formation of activated factor XII would be ___
enhancing the action of antithrombin III
a deficiency of platelets would ___ the ability of blood to coagulate
decrease
___ will directly dissolve of liquefy a blood clot
plasmin
which is an activator of plasminogen
streptokinase
the syncytial nature of cardiac muscle is due to
intercalated discs
compared to a typical cardiac muscle, purkinje fibers have
decreased actin and myosin
how would tetradotoxin affect a typical cardiac muscle action potential
it would shorten the plateau
how are the ventricles protected to some degree from supra ventricular arrhythmias
a longer refractory period of the typical ventricular cells
during depolarization, what sequence of permeability changes is in a typical ventricular cell
sodium calcium permeability increasing, potassium permeability decreasing
the stable resting polarized state in a typical cardiac muscle cell is due to
K at its Nernst equilibrium and an impermeable membrane to Na and Ca
as heart rate increases, cycle length shortens, so
diastole shortens more than systole
a cardiac cell with a conduction velocity of 4 M/sec would most likely be a
typical ventricular cell
in CHF, a reduced ejection fraction may be associated with an increase in
SNS activity
during isovolumic contraction, the mitral valve is ___ and the aortic valve is ___
closed; open
when the papillary muscles in the walls of the ventricles contract and pull on the chordae tenineae
the AV valves are stabilized
when considering the work output of the heart, most of the work in a normal heart is associated with
pressurization of the blood
the principle energy source for cardiac contraction is
FAs
increased stretch on the ventricular myocardium at the end of diastole will
increase calcium influx
a rise in mean aortic blood pressure from 95 to 110 mmHg will
cause an increase in cardiac output
cardiac output is regulated by
overall metabolic demand
the SNS effect on cardiac cells is mediated by all except
alpha receptors
increased activity of the left stellate ganglion will ___ the ventricular fibrillation
increase
PSNS stimulation will ___ K permeability
increase
in an intact heart at a normal resting HR, stretch of the right atrial wall will ___ SNS
increase
if you block both divisions of the ANS, what would be true
HR will increase and strength of contraction will decrease
in the SA nodal cells, the depolarization limb of the action potential is due to
slow CA/Na channels only
if a wave of depolarization is moving towards the negative recording electrode
a positive deflection will be observed
the AV nose functions to
delay the wave of depolarization from entry into the ventricles
