Chapter 25 Flashcards
purpose of circulatory system
transport
circulatory system includes the
heart, arterial system, venous system and capillaries
low pressure pulmonary system allows blood to move through ______ more ______ which is important for gas exchange
lungs, slowly
central system is composed of
heart and pulmonary
most of the blood is found in the
venules
what is the driving force for blood flow
pressure difference between arterial and venous side
exhaling against closed glottis, this impedes
venous return
exhaling against a closed glottis shifts as much as
250 mL of blood
example of exhaling against a closed glottis
weight lifting, bracing core, bracing on the toilet
when in recumbent position (laying flat) 25-30% of blood is in
central circulation
when you stand the blood is rapidly displaced to
lower body parts
hemodynamics describes the
physical principles governing pressure, flow and resistance relating to circulatory system
fluid flow through a vessel depends on
the pressure difference between ends of the vessel, the vessels resistance to fluid flow
viscosity is largely determined by
RBC
if flow is constant velocity is _________ proportional to the cross sectional area of the vessle
inversely
laminar flow
moving in one direction
________ is minimal when laminar flow
friction
turbulent flow occurs with ____ velocity of flow, change in vessel ______ and low blood _____
high, diameter, viscosity
large mitochondria reflects
continuous energy needs
myocardium behaves as a
single unit
myocardium stores less of what electrolyte
calcium
mycardium relies more heavily on an influx of
extracellular calcium for contration
proteins which regulated actin myosin binding are used in diagnosis of MI
troponins
troponins help diagnosis
MI
you test troponin
serially
endocardium is the
innermost layer
endocardium is continuous with
blood vessel
increase of heart rate
tachycardia
decrease in heart rate
Bradycardia
route of electrical conduction to start mechanical contraction
SA node
AV junction
Bundle of His
right and left bundle
purkinje fibers
if the SA node quits working the ____ takes over
AV node
when the AV node takes over the heart rate drops to
40-60BPM
if the AV and SA node do not fire the ventricles can fire and drops the heart rate to
40 BPM
which ion channels allow cardiac muscle to fire without a stimulus
Ca2+
P wave is the depolarization of the
atria
inbetween P and Q wave is the
delay in AV node
QRS complex is the depolarization of
ventricles
end of S to T wave is the depolarization of
ventricles
absolute refractory period takes place between
QRS and peak T wave
absolute refractory period
cardiac cells cannot be stimulated to conduct an electrical impulse, no matter how strong the stimulus
relative refractory period takes place when
the downslope of the T wave
relative refractory period
cardiac cells can be stimulated to depolarizes if the stimulus is strong enough
supernormal period takes place when
end of the T wave
supernormal period
a weaker than normal stimulus can cause depolarization of cardiac cells
ECG records
electrical voltages generated by depolarization of heart muscle
ECG can provide information about
conduction disturbances, electrical effects of electrolytes and medications, presence of ischemic damage
systole is
contration
diastole is
filling
coronary arteries fill during
filling
systole is between
S1 and S2
diastole is between
S2 and S1
S1 sound is produced by
mitral and tricuspid closure
S2 sound is produced by
aortic and pulmonic closure
S3 is produced by
passive filling stage of diastole
what S are inaudiable
S3 and S4
if S3 can be heard then
often represents an overloaded ventricle, can be physiologic in children but pathologic in adults
S3 could mean
failure
S3 is a ______ sound
diastolic
if S4 can be heard then
it is produced by atrial contraction during diastole
tachycardia decreases ________ filling and ______ artery filling time
ventricle, coronary
mural thrombus
clot on wall of heart which is caused by stagnant blood
diastole
ventricles relaxed
blood entering atria
blood flows through AV valves into ventricles
semilunar valves are closed
systole
ventricles contract
blood pushes against AV valves and they shut
blood pushes through semilunar valves into aorta and pulmonary trunk
only way to safely take care of patients with heart failure is to know what valule
Ejection Fraction
how to find EF
stroke volume divided by the end diastolic volume
EF represents
the fraction of percentage of the diastolic volume that is ejected from the heart during systole
stroke volume is made up of 3 things
preload, contractility, afterload
cardiac output
liters per min
stroke volume
how much is pushed out in one beat
preload is the proportional to stretch of myocardium at end
diastole
preload represents the amount of
gas in the take/filling pressure
afterload is the pressure
the heart must generate to move blood into the aorta
afterload is the resistance the heart must pump
against
_______ relationship between afterload and cardiac performance
inverse
contractility
the rate, extent and force of fiber shortening during systole for a given set of loading conditions
another name for contractillity
inotrophy
central circulatory system consists of
heart and pulmonary
exhaling against a closed glottis impedes venous return and shifts as much as _____ mL of blood
250
turbulent flow occurs with
high velocity of flow, change in vessel diameter and low blood viscosity
proteins which regulated actin-myosin binding are used in diagnosis of MI
troponins
3 cations associated with depolarization and repolarization
Ca+, Na+ and K+
an high T wave may indicate
hyperkalemia
coronary arteries fill during
diastole
S1 is produced by
mitral and tricuspid closure
S2 is produced by
aortic and pulmonic closure
S3 is a sign of
HEART FAILURE
S3 is what type of sound
diastolic
tachycardia causes decrease in ________ filling and decrease in _________ artery filling time
ventricular, coronary
stagnat blood can cause a
mural thrombus
mural thrombus is a
clot on wall of heart
what is the only way to safely take care of a patient with heart failure
knowing their ejection fraction
preload is known as
gas in tank
contractility is
stretch of fibers
afterload is
resistance heart has to pump against
preload is proportional to
stretch of myocardium at end of diastole
afterload is the resistance the heart must pump
against
there is a ________ relationship between afterload and cardiac preformance
inverse
inotropy
another word for contractility
