Blood Pressure Regulation Flashcards
(101 cards)
1
Q
Cardiac Output Formula
A
CO=HRxSV
2
Q
Regular Cardiac Output
A
5000mL
72bpmx70mL
3
Q
Stroke Volume Formula
A
SV=EDV-ESV
70mL=120mL-50mL
4
Q
Frank Sterling Law
A
heart has intrinsic ability to change SV in response to input (venous return)
the heart pumps what it recieves
5
Q
Preload
A
filling of the ventricle
increases SV
direct result of venous return
6
Q
Contractility
A
heart contracts more or less forcefully
increases SV
7
Q
Afterload
A
pressure the heart must overcome to eject blood
decreases SV
blood pressure
8
Q
Ejection Fraction
A
SV/EDV
normally 60%-70%
9
Q
Positive Inotropes
A
increase contractility, increase Ca++ flow, increases cAMP
examples are Epinephrine, Caffiene, and digitalis
10
Q
Chronotropes
A
increase cardiac rate
11
Q
Sympathetic Chronotropes
A
positive inotropes, increases cardiac rate,
Epinephrine, Norepinephrine
12
Q
Parasympathetic Chromotropes
A
negative inotropes, decreases cardiac rate
Vagus Nerve via ACh
Atropine blocks ACh, stimulating cardiac rate
13
Q
Max Heart Rate Formula
A
- Old Formula: 220-age in years
- New Formula: 208-(0.7xage in years)
14
Q
CO in Tachycardia
A
in a heart rate over 170bpm CO is decreased die to insufficient filling time
15
Q
Digitalis
A
enhances Ca++ entry, increases contractility
antidepressant
16
Q
Nitroglycerin
A
cardiac vasodilator, increases preload
17
Q
Ca++ channel blockers
A
smooth muscle antagonist, dilates smooth muscle, lower BP
decreases afterload, negative inotrope
18
Q
Fick Principle
A
used to estimate Cardiac Output in living subjects, application of law of conservation of mass
can be estimated knowing O2 consumption, with arterial pulmonary and venous valves for O2
19
Q
Fick Principle
C.O. (Q) formula
A
(O2 consumption(mL/min))/(O2 arterial - O2 venous)
20
Q
Fick Principle Thermodilution
A
cold saline is used instead of dye and thermal identification is used
21
Q
Fick Principle Thermodilution
C.O. formula
A
(mg of dye injectedx60 sec)/(avg dye conc.(mg/L)xduration of curve in seconds)
22
Q
atherosclerosis
A
hardening of arteies due to gradual plaque buildup
treated by beta blockers, calcium channel blockers, and anti-clotting medications
23
Q
Angina Pectoris
A
squeezing, heaviness, tightness, or pain in the chest
caused by reduced blood flow to the heart muscle (ischemia)
24
Q
Coronary Bypass
A
surgical procedure to treat coronary artery disease
reroutes blood flow from clogged coronary arteries to arteries and veins harvested from elsewhere, utilizes a bypass machine
25
Angioplasty
minimally invasive procedure meant to widen narrowed or obstructed arteries and veins
## Footnote
uses guide wire, catheter, and a balloon
26
The Sounds of Korotkoff
the sounds heard during the measurement of blood pressure
27
Pulse Pressure Formula
Systolic-Diastolic=Pulse Pressure
## Footnote
120mmHg-80mmHg=40mmHg
28
Mean Arterial Pressure
Effectivness of the heart as a pump, resistance to blood flow, distribution of blood between arterial and venous blood vessels
29
Mean Arterial Pressure Formulas
MAP=(1/3)Pulse Pressure + Diastolic Pressure
MAP=(1/3)(2Diastolic Pressure + Systolic Pressure)
MAP=COxTPR(total peripheral resistance)
30
Formulas for Flow
DeltaP/R
MAP/Resistance
## Footnote
Resistance to flow = 1/(radius)^4 or MAPx(radius^4)
31
Arterioles
Resistance vessels in system
| pressure flow regulators
## Footnote
small in diameter
32
Venuoles and Veins
capacitance vessels
| volume storage
## Footnote
54% of blood volume is in venous system
33
Capillaries
exchange vessels (O2, CO2, hormones)
| largest area
## Footnote
5 liters or blood but 8-10 liters of capillary space
34
shunting example
increased blood flow to the digestive system after eating, reducing blood to other systems
35
Which organ requires the most blood?
the kidney requires the most blood per gram
36
Continuous Capillary
body capillaries with confluent lining
37
Fenestrated Capillaries
capillary endothelium has windows or pores called fenestra
## Footnote
in kidneys and intestines
38
Sinusoidal Capillaries
wide clefts between endothellial cells
## Footnote
in liver, bone marrow, and lymphatic system
39
Law of Laplace Formula
Pressure = Wall Tension / radius
| T/r
40
Batista Procedure (Brazil)
removes part of the ventricular wall of an enlarged heart, reducing the radius, then less tension is required to mantain blood pressure
41
Bernoulli Principle
sum of kinetic energy and flow energy in a closed system is constant, when fluid moves from a wide to narrow tube, potential energy falls as velocity increases and kinetic energy increases
## Footnote
lower pressure in smaller diameter tube with faster velocity
42
Blood Pressure Regulators
1. Autonomic Nervous System
2. Baroreceptors
3. Renal Mechanisms
4. Role of Venous Return
5. Role of Hormones
6. Autoregulation
7. Chemoreceptors
8. Effect of Temperature
43
# ANS
Sympathetic BP Regulation
increase heart rate, force of contraction, Alpha Receptors Vasoconstrict w/ NE
## Footnote
Beta 1 receptors increase heart rate and force of contraction
44
# ANS
Parasympathetic BP Regulation
decrease heart rate via vagus nerve, ACh, no effect on contraction force
45
# ANS
Acetylcholine and BP regulation
ACh is a vasodilator, but usually not a force in blood flow regulation
46
# ANS
Medullary Ischemia
ischemia to the medulla oblongata triggers body wide vasocontriction, increased HR and contractility
47
Most Important Flow Regulator
vasocontriction
## Footnote
will restrict flow to nonessential organs
48
Baroreceptors
most important short term regulator, rapid acting
## Footnote
located in the carotid sinus and aortic body
49
Effect of increased BP on Baroreceptors
1. BP increase
2. Baroreceptors increase firing
3. Excites vagal nerve (decreased HR)
4. Inhibits Medullary vasocontriction centers
## Footnote
Decrease is the opposite
50
Baroreceptors long term
not good at long term BP regulation as they reset after several days with a prevailng BP
51
Orthostatic Hypotension
pressure compensation from lying to standing
51
Renal Mechanisms
Very important long term regulator
52
Renal Angiotension Aldosterone System (RAAS)
hormone system that regulates blood pressure
## Footnote
when renal blood flow is reduced Angiotension is released, which vasocontricts
53
J-G Apparatus
contains renin producing cells
54
RAAS Steps
1. Macula Densa of DCT senses decrease in Renal BP
2. Increase in Renin release by J-G apparatus is signaled
3. Renin acts on Angiotensinogen making Angiotensin 1,
4. Angiotensin 1 is altered by Angiotensin Converting Enzyme(ACE)
5. Angiotensin 2(vasocontrictor) is made
6. Angiotensin 2 triggers Aldosterone release
7. Aldosterone increases sodium and water reabsorbtion by distal tubule, increasing blood volume and blood pressure
8. Angiotensin 3 acts as a vasoconstrictor
55
Factors of Venous Return
1. Venous Valves
2. Skeletal Muscle Pump
3. Thorasic Pump Inhalation
56
Venous Valves
???
57
Skeletal Muscle Pump
When skeletal muscles contract and squeeze veins, pushing more blood toward the heart.
58
Thoracic Pump Inhalation
venous return is increased during to inhalation due to increased pressure on abdoninal veins and decreased pressure on throracic veins
59
Endothelium Derived Relaxing Factor (EDRF)
Endothelium derived relaxing factor, relaxes vascular smooth muscle
## Footnote
Nitroglycerin, Viagra
60
Bradykinin
vasodilator, increases vascular permeability,
61
Histamine
vasodilator, constricts EDHF to produce vasodilating agents
62
Epinephrine
dilator in heart , liver, skeletal muscle, B2 receptor activation
63
Atrial Natriuretic Peptide/Factor (ANP/ANF)
1. Released by an increase in BP
2. Causes Vasodilation
3. Opposite action of Aldosterone
## Footnote
Vasodilates by increasing kidney sodium secretion by DCT, water excretion, less volume, less BP
64
prostocyclin
inhibits platelet aggregation, vasodilator
65
Thromboxane
platelet aggregator, vasocontrictor
66
aspirin
cyclooxygenase inhibitor, inhibits platelet aggregation
67
Autoregulation
Myogenic Theory and Metabolic Theory
68
Myogenic Theory
smooth muscles reaction to stretch is contraction as BP increases, vessel wall contracts, flow "autoregulates"
69
Metabolic Theory
tissues produce vasodilators,
decrease in flow -> vasodilators accumulate
increase in flow -> vasodilators wash away
70
Active Hyperemia
metabolic demand of tissue causes vasodilation
## Footnote
skeletal muscle, digestive tract
71
Reactive Hyperemia
transient increase in organ blood flow following a brief period of ischemia
72
Chemoreceptors
more important at lower pressures,
73
Chemoreceptor vasodilation
increase PCO2, H+
decrease in pH
decrease PO2
74
Effect of temperature
increase: vasodilation
decrease: vasoconstrict
75
Four Starling Forces
determine fluid movement in capillaries
## Footnote
Pc, Pi, pic, pii
76
Pc
hydrostatic pressure in capillary(filtration force)
| primary outward force
## Footnote
tends to force fluid out of the capillary
77
Pi
hydrostatic pressure of interstitial fluid(0 or filtration force)
| weak force
## Footnote
zero to negative in value
78
pic
oncotic pressure of capillary plasma proteins(reabsorbtion force)
## Footnote
tends to force fluid into the capillary
79
pii
oncotic pressure of interstitial fluid proteins(filtration force)
## Footnote
tends to force fluid out of the capillary
80
Net filtration rate formula
L[(Pc-Pi)-(pic-pii)]
81
arterial side of capillaries
have a net outward force (filtration)
82
venous side of capillaries
have a net inward force (reabsorbtion)
83
summation of both arterial and venous capillaries
yields a net outward force (filtration)
## Footnote
2mL/min
84
Lymphatic system funciton in fluid accumulation
lymphatic system shunts fluid and proteins back into circulation from the area around the capillaries
85
Edema Causes
high capillary permeability(blood pressure), low blood protein(starvation), lymphatic blockage(mastectomy, cancer), increased capillary permeability
86
High Blood Pressure
140/90 mmHg
87
Primary or Essential Hypertension
Hypertension from an undetermined cause
88
treatment of hypertension
1. Diuretics
2. Beta Blockers
3. Calcium Channel Blockers
4. Ace inhibitors
5. ARB(s)
89
Diuretics
decrease fluid absorbtion by kidney
## Footnote
fluid loss = blood volume loss = blood pressure drop
90
Beta Blockers (B1 receptors)
decrease heart rate, contractility due to B1 receptrors blocking
## Footnote
blood pressure drop due to decreased heart pump functions
91
Calcium Channel Blockers
block calcium entry into muscle, esp smooth muscle of vasculature
## Footnote
blocks vasoconstriction
92
ACE inhibitors
blocks Angiotensin Converting Enzyme "ACE", less Angiotenin 2 and Aldosterone production,
## Footnote
less vasoconstriction and less Na+ and volume recovery by Kidney
93
ARB(s)
Angiotensin Receptor Blockers, blocks Angiotensin receptor at the target tissue level
## Footnote
blocks vasoconstriciton and adrenal release of Aldosterone
94
Alpha 1 receptors
stimulates contraction of smooth muscles, increases IP3
95
Alpha 2 receptors
same as A1 receptors, also inhibits smooth muscle contraction of the GI system, decrease cAMP
96
Alpha receptors
greater affinity for NE
97
Adrenergic Receptors
Alpha and Beta Receptors
98
Beta 1 receptors
stimulates heart rate, contractility, increase cAMP
99
Beta 2 receptors
inhibits smooth muscle, increase cAMP, esp in lung, heart, skeletal muscle blood vessels
100
Beta 3 receptors
fat exclusively, lipolysis, increase cAMP
