CV System: The Physiology Of Circulation Flashcards
Arterial pressure is generally controlled independently of
Local tissue flow or CO
Circulation is influenced by
Blood flow, pressure,resistance, control mechanisms mediating these characteristics
Transport blood under high pressure, strong vascular walls, rapid blood flow
Arteries
Final small branches of arterial system, act as control conduits-blood released into capillaries, strong muscular walls that vasoconstriction/dilate, innervated by SNS only
Arterioles
Percent of total blood volume in veins
64
Do veins have thick or thin walls
Thin, low pressure
Distribution of blood volume systemically
Veins-64%
Arteries-15%
Capillaries-5%
Heart holds __ % of total blood volume
7
Pulmonary system holds __% of blood volume
9
Blood flow affected by 2 factors
Pressure gradient, vascular resistance
Ohm’s law
F = change in pressure between 2 ends of vessel/ resistance
Two descriptions of flow
Laminar, turbulent
What is the reciprocal of resistance
Conductance
Measure of blood flow through a vessel for a given pressure difference
Conductance
Small change in ____ causes enormous change in conductance
Diameter - conductance of vessel increases in proportion to the 4th power of diameter
Poiseuille’s law states that _____ plays the greatest role in determining rate of LAMINAR flow
Diameter
____ of systemic resistance to flow is
2/3, arteriole resistance
Strong muscular walls of arteriole can change diameter up to ___fold. Which in turn increases blood flow up to ___fold
4,256
Viscosity has an ________ relationship to blood flow
Inverse
Pressure that propels blood to tissues
MAP
Affected by Stroke volume and compliance of arterial tree
Pulse pressure
MAP and plus pressure ____ with increasing distance from heart
Decreases
Is distensibility higher in veins or arteries
Veins
Total quantity of blood that can be stored in a given portion of the circulation for each mmHg pressure rise
Compliance or capacitance