1
❖ Chap 16: Alterations in BP
➢ Principles of Flow
■ Different Pressure Gradients
● Left ventricle (SBP) and right atria (DBP)
● Pressure inside of capillary and the interstitial tissues
❖ Endema can be caused by
➢ Increased capillary pressure
■ Congestions of vein and/or right heart
➢ Decreased plasma colloid osmotic pressure
■ Low albumin
● Caused
◆ liver disease
◆ Kidney disease
➢ Differences
Direct Measure of BP ❖ Requires intraarterial catheter and specialized
equipment to transduce arterial fluid pulsation
into electrical signals (waveforms)
❖ Catheters commonly placed in radial artery
❖ Most accurate method of measuring BP
Indirect Measure of BP ❖ Requires technique to ensure accuracy
❖ Commonly measured via brachial artery using
stethoscope and sphygmomanometer or
automated oscillometric system
❖ Auscultation of Korotkoff sounds (indication for
each sound?)
, 2
➢ Systolic pressure (SBP): onset of k
sounds
➢ DIastolic pressure (DBP): disappearance
of K sounds
❖ White coat effect
❖ Elderly: auscultatory gap (period of diminished or
absent K sounds during the manual
measurement of BP)
Determinants of systemic BP (SBP and DBP) ❖ Cardiac output and resistance to ejection of
blood from the heart
➢ CO=SV(stroke volume) x HR
➢ End diastolic volume = preload
■ Amount of blood returned to heart
➢ Systemic vascular resistance
(SVR,afterload) is determined by the
radius of arteries and degree of vessel
compliance
❖ Long-term/short term factors affect BP by
altering CO, preload and or afterload
➢ Understand how- will help understand the
medication usages
Mechanisms of BP regulation ❖ Short-term regulation of systemic blood
pressure-SNS**
➢ Changes in BP are mediated through
activation of the sympathetic nervous
system
■ Epinephrine and norepinephrine
(how?which receptors)
● PNS: slow Heart beat and
contractility
❖ Long-term reg bp 1
➢ sodium/water
■ increased blood fluid volume
■ Increased preload and afterload
➢ renin(kidney)
■ angiotensin(liver)
■ aldosterone(adrenal gland)
system
■ RAAS system
➢ Atrium natiruetic peptide/brain natriuetic
peptide
■ Decreased body fluid volume
, 3
● Decreased preload and
afterload
➢ Renin
■ Angiotensin
■ Aldosterone system (RAAS) =
important regulator of BP
● Juxtagolular cells when
stim by low arterial
pressure release renin
◆ Activates
angiotensinogen to
angiotensin I
● Angiotensin i when in
contact with ACE activates
angiotensin II
◆ 1. A potent
vasoconstrictor
(afterload)
◆ 2 stim release of
aldosterone
◆ 3. Remodify the
myocardial
cells--hypertrophy
● Aldosterone, a hormone
causes reabsorption of
sodium and water
passively follow/preload
❖ Long-term reg of Systemic BP 2
➢ Atrial natriuretic peptides/ANP and brain
NP
■ Cause kidneys to increase
sodium and water excretion by
increasing the glomerular filtration
rate
● Result in decreased
◆ Preload
◆ BP
◆ DBP
❖ Chap 16: Alterations in BP
➢ Principles of Flow
■ Different Pressure Gradients
● Left ventricle (SBP) and right atria (DBP)
● Pressure inside of capillary and the interstitial tissues
❖ Endema can be caused by
➢ Increased capillary pressure
■ Congestions of vein and/or right heart
➢ Decreased plasma colloid osmotic pressure
■ Low albumin
● Caused
◆ liver disease
◆ Kidney disease
➢ Differences
Direct Measure of BP ❖ Requires intraarterial catheter and specialized
equipment to transduce arterial fluid pulsation
into electrical signals (waveforms)
❖ Catheters commonly placed in radial artery
❖ Most accurate method of measuring BP
Indirect Measure of BP ❖ Requires technique to ensure accuracy
❖ Commonly measured via brachial artery using
stethoscope and sphygmomanometer or
automated oscillometric system
❖ Auscultation of Korotkoff sounds (indication for
each sound?)
, 2
➢ Systolic pressure (SBP): onset of k
sounds
➢ DIastolic pressure (DBP): disappearance
of K sounds
❖ White coat effect
❖ Elderly: auscultatory gap (period of diminished or
absent K sounds during the manual
measurement of BP)
Determinants of systemic BP (SBP and DBP) ❖ Cardiac output and resistance to ejection of
blood from the heart
➢ CO=SV(stroke volume) x HR
➢ End diastolic volume = preload
■ Amount of blood returned to heart
➢ Systemic vascular resistance
(SVR,afterload) is determined by the
radius of arteries and degree of vessel
compliance
❖ Long-term/short term factors affect BP by
altering CO, preload and or afterload
➢ Understand how- will help understand the
medication usages
Mechanisms of BP regulation ❖ Short-term regulation of systemic blood
pressure-SNS**
➢ Changes in BP are mediated through
activation of the sympathetic nervous
system
■ Epinephrine and norepinephrine
(how?which receptors)
● PNS: slow Heart beat and
contractility
❖ Long-term reg bp 1
➢ sodium/water
■ increased blood fluid volume
■ Increased preload and afterload
➢ renin(kidney)
■ angiotensin(liver)
■ aldosterone(adrenal gland)
system
■ RAAS system
➢ Atrium natiruetic peptide/brain natriuetic
peptide
■ Decreased body fluid volume
, 3
● Decreased preload and
afterload
➢ Renin
■ Angiotensin
■ Aldosterone system (RAAS) =
important regulator of BP
● Juxtagolular cells when
stim by low arterial
pressure release renin
◆ Activates
angiotensinogen to
angiotensin I
● Angiotensin i when in
contact with ACE activates
angiotensin II
◆ 1. A potent
vasoconstrictor
(afterload)
◆ 2 stim release of
aldosterone
◆ 3. Remodify the
myocardial
cells--hypertrophy
● Aldosterone, a hormone
causes reabsorption of
sodium and water
passively follow/preload
❖ Long-term reg of Systemic BP 2
➢ Atrial natriuretic peptides/ANP and brain
NP
■ Cause kidneys to increase
sodium and water excretion by
increasing the glomerular filtration
rate
● Result in decreased
◆ Preload
◆ BP
◆ DBP
