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What is arterial blood pressure?
the pressure differences between the L and R sides of the heart that produce gradient allowing systemic movement of the blood
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How is arterial bp produced?
it is produced by the force of left ventricular contraction overcoming the resistance of the aorta to open the aortic valve
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Determinants of systemic BP?
What is the equation?
What is the preload and afterload?
- CO = SV (stroke volume) X HR (heart rate)
- End-diastolic volume is preload
- systemic vascular resistant is the afterload
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How is systemic vascular resistance determined?
the afterload is determined by radius of arteries and degree of vessel compliance
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Components of BP
- systolic bp
- diastolic bp
- SV (stroke volume) - primary influences systolic pressure
- SVR (systemic vascular resistance) - for diastolic pressure
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mean arterial pressure
- avg pressure within circulatory system thru-out cardiac cycle
- MAP =

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where is the catheter commonly placed?
radial artery
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direct measurement of bp
intraarterial catheter to transduce arterial fluid pulsations into electrical signals/waveforms
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indirect measurement of bp
- via brachial artery using stethoscope and sphygmomanometer or automated oscillometric system
- Korotkoff sounds
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What affects bp regulation
by neural, humoral, and renal factors
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short term regulation of systemic bp
- changes in bp mediated thru activation of sympathetic nervous system
- -results in release of nt: epinephrine & norepinephrine
- -vasomotor center indirectly activated via baroreceptor
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which baroreceptors activates what?
- α1 receptors in smooth muscle of arterioles
- β1 receptors of the heart
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long term regulation of systemic bp
- ^ in extracellular fluid vol. = ^ CO and SVR = elevated BP
- -^ serum sodium level = ^ osmolality = ^ ADH secretion
- -RAAS: renin-angiotensin-aldosterone system are important regulator of bp
- angiotensin II produces ^ in SVR
- -Atrial natriuretic peptides (ANP) cause kidneys to ^ sodium and water excretion by ^ glomerular filtrate rate
- -intrarenal arteriolar constriction leads to ^ tubular reabsorption of sodium and water
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normal fluctuations in systemic bp
- suprachiasmatic nuclei in brain govern daily variations in bodily functions
- neural and hormonal regulation and lifestyle influences
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hypertension
- primary diagnosis
- -^morbidity and mortality associated w/ heart disease, kidney disease, peripheral vascular disease, and stroke
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prehypertension
a range of pressures between normal and stage 1 hyptertension in an effort to initiate interventions early enough to prevent/deter progression of disease process
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normal - S/D
prehypertension
- <120 / <80
- 120-139 / 80-89
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primary hypertension
- idiopathic disorder
- common form of hypertension
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outcomes of primary hypertension
- end organ damage,
- -^ myocardial work results in HF
- -glomerular damage results in kidney failure
- -affects microcirculation of eyes
- -^ pressure in cerebral vasculature can result in hemorrhage
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secondary hypertension
- attributed to specific identifiable pathology/condition
- -common form in children <10 yrs of age
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hypertensive emergency
- sudden ^ in either or both systolic or diastolic bp with evidence of end-organ damage
- -use of parenteral antihypertensive agents under close monitoring
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hypertensive urgency
- similar bp elevation without evidence of end-organ damage
- -oral medications
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low bp
- orthostatic (postural) hypotension is a decrease in systolic bp when moving to an upright position
- -excessive ^ in heart rate (by 15-20 beats/minute) may also be diagnostic
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result of low bp
- -prob. w/ vasomotor/baroreceptor response
- -adverse effect of drug therapy
- -arterial stiffness
- -vol. depletion
- -secondary disease process
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treatment of low bp
- medication history,
- -slow positional changes,
- -avoid hot environments,
- -hydrate,
- -avoid large/carbohydrate-heavy meals
- -when symptoms begin, squatting/bending forward or crossing legs may reduce effects
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