Blood pressure regulation Flashcards
Difference of pressure and mean pressure of artery
mean = Diastolic P + 1/3 pulse P
Pulse P is systolic - diastolic
Why pulse P can travel faster than blood w/in artery
They are independent occurences
Pulse P is a shock wave
Why does shape of PP change down arterial tree
it changes as velocity changes
Less compliant arteries leads to faster PP
Elasticity and velocity
Reciprocal relationship
As E increases PP decreases
Vasoconstriction effects
Arterial diastolic bp increases
Capillary Hydrostatic pressure decreases
Vasodilation effects
Arterial diastolic P decreases, CHP increases due to increased B volume
Vasoconstriction on tone
Stimulation on alpha 1 R
Resistance increased
Reduced blood perfusion
Capillary P decreases
Vasodilation on tone
Reduction of alpha 1 R
Increase in B flow to arteriolar diameter
Diastolic P decreases
Capillary P increases
PARASYMPATHETIC
NO EFFECT OF VESSEL DIAMETER
Vasoconstrictor center
P center
Groups of cells that when stimulated result in vasoconstriction
Vasodilator center
depressor center
Group of cells when stimulated result in vasodilation of areterioles
Cardioexcitatory center
When stimulated causes an increase in sympathetic activity
Increased HR, contractility and conduction velocity of AP
Beta 1 R
Cardioinhibitory center
Increase vagus tone results in decreased heart rate
Baroreceptors decreased stimulation
Activate Vasoconstrictor centers
Baroreceptors increased stimulation
activation of vasodilator center increases vagal tone
PCO2
Increased CO2 exerts local effect on brain causes relaxation of vascular smooth muscle. Vasodilation
Stimulates vasoconstrictor center attempt to raise BP
2 Fx of cholinergic sympathetic fiber
Produces vasodilation in anticipation of activity/exercise
Activates sweat glands in anticipation of activity
Effect of acute decrease BP on firing response from carotid sinus baroreceptor
< in BP means a < in the stretch of baroR
Freq of baroR firing will <
effect is to < in inhibition of the vasoconstrictor center
Effect of acute increase BP on firing response from CS baroR
> BP > the stretch on BaroR
cause > firing of baroR
effect is to increase in the inhibition of vasoconstrictor center
Consequence of adaptation of baroR to hypertension
It resets to new pressure, drugs lower BP the baroR think it is hypotensive activate sympathetic tone
Heart palpitations
Renin angiotensin
Describe carotid sinus reflex
Reclining to standing
< in P in carotid sinus
< in P + flow to brain
< in fining of baroR
Systemic capillary filtration & readsorption
< filtration
> readsorbtion
Atrial P on ADH release
< in atrial P results in > ADH release -> decrease in water & Na loss
Atrial P stretch on atriopeptin ANF release
Atrial P < will result in < of ANF -> < in water and Na loss
GFR glomerular filtration rate
< BP results in < of GF -> water retention
Sympathetic tone & renin angiotensin aldosterone system
< BP > sympathetic tone activates vasoconstrictor center and renin to ang II
Angiotensin II
> aldosterone production -> > water reabsorption
vasoconstrictor
ang II activates thirst centers in brain
Compensation of BP
all compensate for low BP by increasing blood volume
Vasodilation
alpha 1 R decreased sympathetic tone
Vasoconstriction
alpha 1 R increased sympathetic tone
Muscarinic R
- HR
Beta adrenergic
+ HR and contractility
