Regulation of Arterial Blood Pressure Flashcards Preview

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Flashcards in Regulation of Arterial Blood Pressure Deck (23)
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1
Q

Response to head up tilt normally and in autonomic neuropathy

A

HR increase

HR stays the same

2
Q

5 elements of baroreflex

A

Sensor to detect BP

Affarent from sensor to controller

Controller/integrater that compares current with desired

Efferent that carries to effectors

Effectors

3
Q

Sensors of baroreflex

A

Stretch receptors in the carotid sinus and arch of aorta

Inc BP—inc stretch—–inc activation of these receptors

4
Q

Loop with SNA

A

Inc AP…inc barorecptor….dec sympathetic….dec arteriolar smooth muscle contraction….dec resistance…dec BP

5
Q

Majority of baroreflex depends on

A

SNA - NE, Beta 1

Important exception is PS control of HR

6
Q

PS control

A

BP increases….inc PS nerve activity which dec HR via Ach/muscarinc

7
Q

Plasma volume effect

A

Due to atrial stretch receptors in the RA

8
Q

If you eleiminate baroreflex

A

Sinoaortic denervation

BP fluctuates widely but overall average is about the same

9
Q

Barorelfex summary

A

Minimizers moment to moment fluctuations in BP

Other mechs responsbile for LT BP regulation

10
Q

Overview of neural control

A

Vagus acts on heart from BS

Sympathetic nerves from IML…sensory from heart back to IML

Chainganglion also to vasomotor fibers

Fagus nerves to lungs

11
Q

BS anatomy of baroreflex

A

NTS - receives info from caerotid sinus and aortic arch

Nuc ambiguous - vagal efferent to the AV node

RVLM to symp chain to myocardium for sympathetic

12
Q

Full tract of baroreflex in terms of inc BP

A

Sensory to NTS —–to N amb—-activates vagal stimulation

Sensory to CVLM…inhibits RVLM…RVLM normally activates sympathetic

13
Q

Sequence in ogoing from supine to UR

A

Gravity bloods

Starves heart

Dec CO…dec BP…dec cerebral flow

Dec carotid sinus pressure activates baroreflex

Inc SNA, dec PNA,—–tachycardia, inc SV

14
Q

Renovascular
Neurogenic
Salt sensitive

A

Renal artery occlusion to RAAS

Inc SNA means inc CO and TPR

High salt load means inc BV

15
Q

Arterial pathologies
Obesity related
Endothelial dysfunction
Essential

A

Artrial compliance
????
Impaired release of NO
???

16
Q

Why does baroreflex dec in older age

A

Dec in compliacne of the arteires in which baroreceptors reside

17
Q

Mutliple causes of HTN

A

INteractive efrects of dietary sodium and behavioral stress

Humans learn to elevate arterial BP to minimize perception of pain

18
Q

Pmc

A

This is where the arteiral pressure and CVP meet

Mean circulatory filling pressure

19
Q

Vascular function equation

A

VR = (resistance)(Pmc-Pra)

20
Q

Vascular function curve with vasoconstrction

A

Increase the Pmc and moves the curve to the right

21
Q

Starlings curve and vascular ufnction curve plotted on same graph

A

Find the intersetion and this is steady state operating point

22
Q

Effects on vascular fxn/starling curve

A

Inc in SNA shifts the starling curve up

Inc in contractility shifts the vascular function curve to the right

This means heart can perform more work without an increase in preload

23
Q

Positive inotropism on PV loop

A

Dec in ESV and therefore dec in LV diastolic pressure

Inc in SV automatircally fosters increase in pressure graident for venous return