Block 3 Exam Flashcards
1
Q
Implications of Poiseuille’s Law
A
Flow is directly proportional to axial pressure and fourth power of vessel radius
Flow is inversely proportional to length and viscosity
2
Q
Assumptions of Poiseuille equation
A
Fluid must be incompressible
Tube must be straight, rigid, cylindrical, and unbranched, and have a constant radius
Velocity of thin fluid layer at wall must be zero
Flow must be laminar
Flow must be steady
Viscosity of fluid must be constant
3
Q
What does mechanical impedance include
A
Compliant impedance
Viscous (or resistive) impedance
Inertial impedance
4
Q
Compliant impedance
A
Opposes volume change
5
Q
Viscous (or resistive) impedance
A
Opposes flow
R in dP = FR
6
Q
Inertial impedance
A
Opposes change of flow
7
Q
Four factors that generate pressure
A
Gravity
Compliance of the vessels
Viscous resistance
Inertia
8
Q
Role of circulation
A
Homeostasis
Supply and Demand
9
Q
What is hemodynamics and why study it?
A
Study of physical aspects of blood circulation
Control of flow and volume
Relationship to other systems
10
Q
S1 Heart Sound
A
AV valves closing
11
Q
S2 Heart Sound
A
Semilunar valves closing
12
Q
S3 Heart Sound
A
Ventricular filling
13
Q
When is S3 sound normal?
A
Young patients
14
Q
When is S3 sound pathological?
A
Adults
15
Q
S4 Heart Sound
A
Atrial kick
Caused by vibration of ventricular wall
16
Q
Diastole
A
Filling of ventricle
~500ms
17
Q
Systole
A
Ejection from the ventricle
~300 ms
18
Q
Increase Preload
A
Increases EDV and SV
19
Q
Increase afterload
A
Decreases SV
Increases ESV
20
Q
Resistance in series
A
Greater than any individual resistance
21
Q
What parts of circulation use resistance in series?
A
Renal portal system
Hepatic portal system
Hypophyseal portal system
22
Q
Resistance in parallel
A
Far lower resistance than any individual resistance
23
Q
What causes turbulent flow?
A
High velocity Pulsatile flow Changes in vessel diameter Larger vessel diameter Density of blood
24
Q
What does turbulent flow help diagnosis?
A
Stenosis
Murmurs
Shunts
Valvular problems
25
Turbulent flow
Re is greater than 3000
26
Laminar flow
Re is less than 2000
27
What is transmural pressure affected by?
Physical tissue changes
| Wall tension
28
Noninvasive and indirect measurement of cardiac parameters
```
Sphygmomanometry
Dilution methods (urine)
```
29
Invasive and indirect measurement of cardiac parameters
Dilution methods (blood)
30
Noninvasive and direct measurement of cardiac parameters
Ultrasonic flow meters echocardiography & doppler
31
Invasive and direct measurement of cardiac parameters
Angiography cardiac catheterization
32
1st Korotkoff sound
Suprasystolic
No audible sounds
Artery is completely occluded
33
2nd Korotkoff sound
Systolic pressure
First sound
Initial blood slips through with help of ventricular contraction
34
3rd Korotkoff sound
```
Diastolic pressure
Last sound (muffled)
Blood flows into artery while heart rests
```
35
4th Korotkoff sound
True diastolic
| Cessation of sound
36
Compliance
Total quantity of blood that can be stored in a given portion of the circulation for a given rise in pressure
37
Elastance
Opposite of compliance
| Elastic tension exerted by artery when it is stretched by a volume
38
Average CO
5L/min
39
Average HR
60-100 bpm
40
Average stroke volume
70mL
41
Average SBP
120mmHg
42
Average DBP
80 mmHg
43
Average MAP
95 mmHg
44
What can lead to a decreased viscosity?
Low hematocrit
Anemia
Kidney failure
45
What can increase viscosity?
High hematocrit
High altitude
Polycythemia
46
Three pressures in circulation
Driving pressure
Transmural pressure
Hydrostatic pressure
47
Driving pressure
Difference in pressure along axis of vessel
48
Transmural pressure
Pressure difference across vessel wall
49
Hydrostatic pressure
Change in pressure due to gravity
50
Arteries
Distribution system
| High pressure
51
Veins
Collection system
| Low pressure
52
Microcirculation
Diffusion and filtration system
| Arterioles + capillaries + venules
53
Aggregate flow
Conserved at each level of arborization
54
Aggregate cross-sectional area
Increases with arborization
55
Where does the steepest drop in pressure occur?
Across the arterioles
56
Vascular resistance
Depends on action of smooth muscle cells
57
What happens to Pc when Rpost increases?
Increases
58
What happens to Pc when Rpre increases?
Decreases
59
High Young's modulus
High elastance
| Low compliance
60
Low Young's Modulus
High compliance
| Low elastance
61
Blood pressure
Pressure exerted by the blood against the walls of the blood vessels
62
Systolic pressure
Pressure exerted in the arteries while blood is leaving the heart
63
Diastolic pressure
Pressure exerted in the arteries during the filling of the ventricle
64
Narrow pulse pressure
Commonly indicates decrease in stroke volume
65
Wide pulse pressure
Commonly indicates decrease in compliance of the aorta
66
Cardiac tamponade
Blood fills the pericardial sac surrounding the heart, which decreases the ability of the heart to expand, leading to a decrease in preload and stroke volume
67
Aortic valve stenosis
Narrowing of aortic valve, causing decrease in radius of aortic valve
68
What does increasing driving pressure lead to?
```
Increase transmural pressure
Elastic wall distension
Increase radius
Decrease viscous resistance
Increase conductance
Pressure-flow curve steepens
```
69
High pressure system
Left ventricle in contracted state to systemic arterioles
70
Low pressure system
Systemic capillaries back to the right heart, through the pulmonary circuit, into the left heart in the relaxed state
71
Three groups of capillaries
Continuous
Fenestrated
Discontinuous (Sinusoidal)
72
Continuous capillary
Most common form
| Interendothelial junctions
73
Fenestrated capilary
Perforated with fenestrations
| Surround epithelia
74
Discontinuous capillary
Large gaps
Fenestrae
Found in sinusoids
75
AV valves
Inlet valves of ventricles
76
Tricuspid valve
Between right atrium and right ventricle
77
Mitral valve
| Bicuspid valve
Between left atrium and left ventricle
78
Seminlunar valves
Outlet valves of ventricles
79
Pulmonary valve
Between right ventricle and pulmonary artery
80
Aortic valve
Between left ventricle and aorta
81
Cardiac cycle phases
Inflow phase
Isovolumetric contraction
Outflow phase
Isovolumetric relaxation
82
Inflow phase
Inlet valve is open
| Outlet valve is closed
83
Isovolumetric contraction
Both valves are closed
84
Outflow phase
Outlet valve is open
| Inlet valve is closed
85
Isovolumetric relaxation
Both valves are closed
86
Protodiastolic gallop
Ventricular gallop
| S1-S2-S3
87
Presystolic gallop
Atrial gallop
| S4-S1-S2
88
Maximize rate of O2 uptake
Increase HR
Increase SV
Increase Oxygen extraction
89
Microcirculation components
```
Terminal arteries
Arterioles
Metarterioles
Precapillary sphincters
True capillaries
Venules
```
90
What components are innervated?
Terminal arteries
Arterioles
Venules
91
What components are not innervated?
Metarterioles
Precapillary sphincters
True capillaries
92
Parts of true capillaries
Basement membrane
Interendothelial junctions/tight junctions/claudins
Coated pits/caveolin-coated vesicles
Glycocalyx
93
Vasoconstriction
Increased resistance
94
Vasodilation
Decreased resistance
95
Vasomotion
Rhythmic oscillations superimposed on a tonic contraction
OR
Spontaneous contractions caused by rhythmic oscillations in Ca2+ and membrane potential
96
Partial pressure of O2 depends on:
```
Dissolved O2 in blood
O2 content of RBC
Capillary blood flow
Radial diffusion coefficient of O2
Capillary radius
O2 consumption by surrounding tissue cylinder
Axial distance along length of capillary
```
97
Solute flux
Refers to movement of solute X per cm^2 of capillary wall
98
Solute flow for an entire organ
Addition or removal of solute X to/from the organ
99
Positive Jv
Filtration
| Water leaving capillary
100
Negative Jv
Absorption
| Water entering capillary
101
Jv
Volume flux
102
Lp
Hydraulic conductivity
103
Pc
Hydrostatic pressure in capillary
104
Pif
Hydrostatic pressure in interstitial fluid
105
Pi(c)
Colloid osmotic pressure in capillary
106
Pi(if)
Colloid osmotic pressure in interstitial fluid
107
Sigma
Average colloid osmotic reflection coefficient of capillary wall
108
What decreases pi(c)
Nephrotic syndrome
Pregnancy
Malnutrition
109
Starling force
Mechanical pressure difference
110
Starling hypothesis
Overall transendothelial gradients of starling forces, obtained from "bulk solution" measurements of P and pi
111
Endothelial cells of initial lymphatics
Oak leaf-shaped
Lack junctions at tip
Anchored on sides by discontinuous button-like junctions
112
Endothelial cells of collecting lymphatics
Conventional, continuous, zipper-like junctions also found in endothelial cells of blood vessels
113
Free edges
Sites of fluid transit
114
Three convective loops of extracellular water
Cardiovascular loop
Transvascular loop
Lymphatic loop
115
Distribution of vessels
Conductance vessels
| Arteries
116
Diffusion/Filtration vessels
Capillaries
117
Resistance vessels
Arterioles
| Venules
118
Collection vessels
Capacitance vessels
| Veins
119
Pulse pressure
SBP - DBP
120
Perfusion Pressure
Pa - Pv
121
Artery makeup
Intima
Media
Adventitia
122
Adventitia makeup
Collagen
Fibroblasts
Vasa vasorum
Nerves
123
Normal endothelial cell function
```
Impermeable to large molecules
Anti-inflammatory
Resist leukocyte adhesion
Promote vasodilation
Resist thrombosis
```
124
Normal smooth muscle cell function
Normal contractile function
Maintain extracellular matrix
Contained in medial layer
125
Activated endothelial cell function
```
Increase permeability
Increase inflammatory cytokines
Increase leukocyte adhesion molecules
Decrease vasodilatory molecules
Decrease antithrombotic molecules
```
126
Activated smooth muscle cell function
Increase inflammatory cytokines
Increase extracellular matrix synthesis
Increase migration and proliferation into subintima
127
Regulation of vascular tone
Multi-organ system input
128
Extrinsic regulation of vascular tone
Constriction
Neural
Humoral
129
Intrinsic regulation of vascular tone
```
Dilation
Tissue metabolites
Local hormones
Myogenic
Endothelial factors
```
130
Nitric oxide
Vasodilator
131
EDHF
Vasodilator
132
ET-1
Vasoconstrictor
133
PGI2
Vasodilator
134
P-MLC/t-MLC ratio
Molecular signature of smooth muscle cell force production
135
Endothelial cell function
Respond to shear and other stimuli
136
Health of endothelium
Determines the net effect of signals to endothelial and smooth muscle cells
137
O2 consumption
Cardiac work
138
Coronary flow reserve
Exercise stress test
139
Chemical stress test
Adenosine infusion
140
Vascular disease
Endothelial dysfunction, early marker of vascular disease
141
Mechanism of vascular disease
Reduced bioactivity of NO
Oxidative stress: NO inactivation
Decreased NO synthase protein
142
Vascular disease featured in:
Diabetes
Hypertension
Atherosclerosis
143
Autoregulation
Intrinsic ability of an organ to maintain a constant blood flow despite changes in perfusion pressure
144
High autoregulatory ability
Cerebral
Coronary
Renal
145
Low autoregulatory ability
skin
146
Formed elements of blod
RBCs
WBCs
Platelets
147
GM-CSF
Stimulates proliferation of a common myeloid progenitor
| Promotes production of neutrophils, eosinophils, and monocytes
148
G-CSF and M-CSF
Guide ultimate development of granulocytes and monocytes-macrophages/dendritic cells
149
IL-5
Sustains terminal differentiation of eosinophilic precursors
150
EPO
Homologous to TPO
| Supports erythropoiesis
151
Proerythroblasts
Lack hemoglobin
152
Major tasks of RBCs
Carrying O2 from lungs to systemic tissues
Carrying CO2 from tissues to lungs
Assisting in the buffering of acids and bases
153
Two functions of macrophages
Phagocytosis of pathogens or cellular debris
| Presentation of antigens to lymphocytes
154
Wigger's diagram phase 1
Filling
| Inlet valve is open
155
Wigger's diagram end of phase 1
Atria contraction
| Atrial kick
156
Wigger's diagram phase 2
Isovolumetric contraction
157
Wigger's diagram phase 3
Outlet valve opens
| Ejection
158
Wigger's diagram phase 4
Isovolumetric relaxation
159
What do smooth muscle lack that both skeletal and cardiac have?
Troponin
160
VSMC contraction
Increased Ca2+
Decreased cAMP
Decreased cGMP
161
VSMC relaxation
Decreased Ca2+
Increased cAMP
Increased cGMP
162
Requirements of vasomotion
```
Endothelial cells
VSMCs
Cav channels
Cl channels
SR (SERCA + RYR)
Gap junctions
```
163
What is not required for vasomotion
Neuronal input
164
Regulated contraction
Central
| Local
165
Central control
Nervous system
| Humoral agonists
166
Local control
Myogenic
Metabolic
Endothelial
167
Nervous system control
NE
Epi
ATP
Neuropeptide Y
168
Sympathetic vasoconstriction in blood vessels
Norepinephrine
169
Adrenal medulla mediated vasodilation of blood vessels
Epinephrine
170
Parasympathetic vasodilation of erectile tissue
Co-release of ACh, NO, VIP
171
Parasympathetic vasodilation of salivary gland
ACh
172
Sympathetic vasodilation of sweat gland
Cholinergic ACh
173
Sympathetic vasodilation of blood vessels of muscle
Cholinergic ACh
174
Humoral control
Angiotensin II
ADH
Serotonin
Neuropeptide Y
175
Endocrine/Paracrine vasoconstriction
Angiotensin II
ADH
Serotonin
Neuropeptide Y
176
Endocrine/Paracrine vasodilation
Histamine
VIP
ANP
177
Local control
Myogenic
Metabolic
Endothelial
178
Endothelin
Vasoconstrictor
179
Nitric oxide
Vasodilator
180
Autoregulation location
Coronary
Cerebral
Renal
181
Systemic capillaries
No capillary pulse
182
Pulmonary capillaries
Small pulsations
