Ch 10.1 -- Patterns and Physics of Blood Flow -- VTPP 435

Ch 10.1 -- Patterns and Physics of Blood Flow -- VTPP 435

Recondition

adjusting of blood composition by organs to maintain homeostasis

Flow Rate of Blood

-volume of blood passing thru a vessel per units of time
-F = P/R

Pressure Gradient

-difference in pressure between 2 regions that drives movement of blood from higher pressure region to lower pressure region
-higher pressure at beginning of vessel than at end

Resistance

hindrance of blood flow thru a blood vessel
-caused by friction between moving fluid & stationary vascular walls
-increased surface area of vessel touching blood = increased resistance
-R = ηL/r

Viscosity (η)

-friction development between molecules of a fluid as they slide over each other during flow of fluid
-more RBCs = increased η

Poiseuille's Law

equation that determines flow rate through a vessel

Arterioles

-vessels that branch from arteries in organs
-diameter can be altered to regulate amount of blood distributed to various tissues
-highly muscular
-high resistance
-small radii

Capillaries

-thin-walled
-pore-lined smallest blood vessels
-across which exchange between blood & surrounding tissues take place
-branch off from arterioles
-merge to form venules, venules merge to form veins

Microcirculation

-all the arterioles, capillaries, & venules collectively
-all located within the organs
-pulmonary circulation also has all same vessels

Veins

-thin walled compared to arteries
-highly distensible
-large radius

Arteries

-thick wall
-highly elastic wall
-large radii