Practice Q's Flashcards
more than half of the delay of signal in heart occurs in which area?
AV node
in a typical ekg, which wave occurs at beginning of atrial contraction
p wave
what event is not normally seen on an ekg?
atrial repolarization
what is the direction of the 3 bipolar leads?
1 = 0 degrees 2 = 60 degrees 3 = 120 degrees
which bipolar lead is connected to both arms?
lead I
which bipolar lead has the highest amplitude for the normal qrs wave? and what is the reason to describe this?
lead II because it is most parallel to the vector for the depolarization qrs wave
what is the mean electrical axis of the normal ventricles
59
what conditions result in tachycardia
- toxic conditions of the heart
- increased body temp.
- sympathetic nerve stimulation
an ekg with all normal waves present but they are spread far apart
sinus bradycardia
an ekg with P waves that don’t always have an associated QRS complex
AV block
circus mvts are the basis of
heart fibrillation
84% of blood is in the
systemic circulation
64% of systemic blood is found in
veins
blood flow resistance is inversely proportional to which of the following? viscosity vessel diameter density 1 and 3
vessel diameter
if rate of blood flow thru entire system is 100mL/sec and pressure difference between systemic arteries and veins is 100mmHg, what is the total peripheral resistance?
1 PRU
Reynolds number is a measure of ?
tendency for turbulence
what is the viscosity of blood with a hematocrit of 38-42?
3.0
veins are about ____ distensible than that of arteries
8x more distensible
vascular compliance is _____ to volume increase and ________ to pressure
directly
indirectly related
what is the measure of the ease with which a hollow viscus may be distended?
compliance
what is true of compliance and elastance, when there is a greater amount of elastic tissue in a blood vessel
lower compliance
greater elastance
high resistance is what group of vessels results in a disappearance in the phasic pressure pattern such seen in the aorta?
systemic arterioles
which forces tends to move fluid inward at the arterial end of the capillary?
- capillary hydrostatic pressure
- neg. interstitial free fluid pressure
- plasma colloid osmotic pressure
- interstitial fluid colloid osmotic pressure
- plasma colloid osmotic pressure
capillary hydrostatic pressure
blood pressure going into capillary
push fluid out of arterioles
negative interstitial free fluid pressure
neg. pressure in interstitial fluid
very small pressure
pulls fluid out of arterioles
interstitial fluid colloid osmotic pressure
pressure generated by proteins and particular matter in interstitial fluid
pulls fluid out of arterioles
plasma colloid osmotic pressure
generated by proteins in blood
mostly by albumins
will pull fluid inward at arterial end
if mean capillary pressure is 17.3, neg. interstitial free fluid is 3.0, and interstitial fluid colloid osmotic pressure is 8.0 and plasma colloid osmotic pressure is 28. what is the total inward force?
28.0
- 3 = outward
- 0 = outward
- 0 = outward
- 0 = inward
a rapid increase in arterial pressure causes an immediate rise in blood flow. but within less than a minute, the blood flow in most tissues returns to almost normal, even though arterial pressure is kept elevated. the return of flow is due to ….. ?
autoregulation of blood flow
what factor is most responsible for controlling the rate of blood flow to each tissue of the body so that it is precisely controlled in relation to tissue need?
oxygen and accumulation of tissue waste products
each tissue of the body = local control
systemic control is entire body not local
which of the following substances would not result in vasocontriction?
a. epinephrine
b. angiotensin II
c. NO
d. endothelin
nitric oxide
a vasodilator
