Overview of Circulation Flashcards
Flow is uniform due to …
distension of the aorta and its branches during systole and elastic recoil of those walls and propulsion of blood during diastole
Cross sectional area inversely related to …
resistance
why pressure drops in arterioles
How is cardiac output accommodated by the pulmonary vascular system?
the pulmonary vascular bed is distensible so can accommodate same CO as systemic circulation
Describe the veins in terms of pressure, resistance, and velocity
decrease pressure, decrease resistance, increase velocity
distensible and easily stretched
velocity slowest in capillaries because
they have the greatest CSA
more CSA
less resistance, flow the same, pressure decreases
the majority of blood volume at any given moment is contained in the ..
venous system
if veins constrict
blood goes towards the heart in healthy people (increase CO)
vascular capacitance
ability of a vessel to increase volume with increasing transmural pressure
C = change in volume/change in pressure
vascular distensibility
percentage increase in vessel volume for a given change in a pressure
if a vessel has a large blood volume and a low transmural pressure then it has a ..
high capacitance
veins for example
vascular resistance
frictional resistance d/t flow of fluid thru a tube
resistance increased with decreasing radius, increased viscosity, increased length
vascular conductance
reciprocal of resistance
how easily blood flows thru tube for a given pressure difference across both ends of the tube
