Regulation of Blood Flow Flashcards
Ohm’s Law
Flow between any two points is pressure difference divided by resistance
Is it more advantageous to regulate blood flow by changing pressure or by changing resistance?
Resistance. Changing resistance allows you to regulate pressure in each organ individually. Changing pressure would have an affect on all organs.
Small changes in radius yield —— changes in resistance?
Large. Resistance is related to the inverse of the 4th power of the radius
Contributors to rapid regulation of vascular resistance at a local level are?
Regulation by local factors
Regulation by the sympathetic nervous system
Regulation by humoral factors.
Slow regulation of vascular resistance involves what?
Reduction in blood vessel lumen size (hypertrophy) and/or change in number of blood vessels per tissue unit
Hyperemia
increased blood flow
Active hyperemia
increased blood flow due to increased function
Reactive hyperemia
follows reduction of blood flow to a specific site
More metabolism =
more blood flow
Less oxygen saturation causes what effect on bloodflow?
less oxygen sat leads to more blood flow
Products of metabolism may play an important role inregulation of blood flow.
Important vasodilator metabolites are ATP, Adenosine, ADP, AMP, Carbon Dioxide, Lactic Acid, Potassium
Products of metabolism may play an important role inregulation of blood flow.
Important vasodilator metabolites are ATP, Adenosine, ADP, AMP, Carbon Dioxide, Lactic Acid, Potassium
Describe how metabolites control blood flow in active hyperemia
Increased tissue activity leads to increased metabolism which leads to increased metabolite accumulation, vasodilation and increased blood flow.
Describe how metabolites control blood flow in active hyperemia
Increased tissue activity leads to increased metabolism which leads to increased metabolite accumulation, vasodilation and increased blood flow.
How do metabolites control blood flow in reactive hyperemia?
Decreased bllod flow leads to an increase in metabolite accumulation which leads to vasodilarion and increased blood flow
How do metabolites control blood flow in reactive hyperemia?
Decreased bllod flow leads to an increase in metabolite accumulation which leads to vasodilarion and increased blood flow
Mechanisms responsible for autoregulation?
Metabolic and Myogenic
Mechanisms responsible for autoregulation?
Metabolic and Myogenic
In the myogenic mechanism, Stretch induces what?
calcium channel activity
In the myogenic mechanism, Stretch induces what?
calcium channel activity
Major innervation of blood vessels?
Sympathetic fibers.
Major transmitter substance is norepinephrine
Major innervation of blood vessels?
Sympathetic fibers.
Major transmitter substance is norepinephrine
Where are blood vessels most heavily innervated?
Cutaneous, renal, splanchnic, skeletal muscle
Where are blood vessels most heavily innervated?
Cutaneous, renal, splanchnic, skeletal muscle
