Exam II Flashcards
(223 cards)
1
Q
What is the main function of systemic circulation
A
Deliver adequate O2, nutrients and remove CO2 and other waste products
2
Q
What does the systemic circulation serve as a conduit for
A
Transport of hormones, allows them to act at a distant site from their production
3
Q
What are designed to carry blood under high pressure out to tissue beds
A
Systemic arteries
4
Q
What act as control valves to regulate local flow
A
Arterioles and pre-capillary sphincters
5
Q
What are one cell layer thick and is the site of exchange btwn. tissues (cells) and blood
A
Capillaries
6
Q
What collect blood from capillaries
A
Venules
7
Q
What return blood to heart/dynamic storage
A
Systemic veins
8
Q
What is blood flow proportional to
A
Metabolic demand
9
Q
What is cardiac output controlled by
A
Local tissue flow
10
Q
What is independent of local flow or cardiac output
A
Arterial pressure
11
Q
What one layer exists in ALL vessels
A
Endothelium
12
Q
Relative composition of Aorta in order: Elastic tissue (1) Smooth m. (2) Fibrous Tissue (3)
A
1>3>2. Elastic tissue, Fibrous tissue, Smooth m.
13
Q
Relative composition of a typical artery in order: Elastic tissue (1) Smooth m. (2) Fibrous Tissue (3)
A
2>3>1. Smooth m., Elastic tissue, Fibrous tissue
14
Q
Relative composition of a vein in order: Elastic tissue (1) Smooth m. (2) Fibrous Tissue (3)
A
1=2=3. Equal
15
Q
What is a capillary made up of
A
ONLY endothelium
16
Q
What is Ohm’s Law
A
V=IR
Voltage = Current flow x Resistance
17
Q
What is the volume of blood that passes a certain point per unit time ex.(ml/min)
A
Flow
18
Q
Flow is directly proportional to _______ and inversely proportional to ________
A
Change in pressure, Resistance
19
Q
What is the driving force of blood
A
Pressure
20
Q
Where does the greatest resistance to flow occur
A
In the pre-capillary resistance vessels (arterioles, metarterioles, precapillary sphincters)
21
Q
Parallel circuit vs. Series circuit
A
P: Rt
22
Q
What kind of circuit is the systemic circulation
A
Predominantly Parallel
23
Q
What are the 3 advantages provided by Parallel Circuitry
A
Independence of local flow control (can inc/dec to tissues independently)
Minimizes total peripheral resistance (TPR)
O2 rich blood supply to every tissue
24
Q
Because the pulmonic and systemic circulations are in series with one another, what is the total vascular resistance (TVR) equal to
A
The sum of the total pulmonic resistance + total peripheral resistance
25
What is the viscosity of blood, and most of it due to
3, due to RBCs
26
What is the viscosity of plasma
1.5
27
Decrease in what will lead to an increase in viscosity
Velocity
28
Where can cells get stuck, leading to a momentary apparent increase in viscosity
Constriction points
29
What increases the flexibility of RBCs
Fibrinogen
30
What is Hematocrit, and what is the normal range
% of packed cell volume (primarily RBCs)
| Normal = 38-45%
31
What type of flow is:
| Streamline, Silent, Most Efficient, Normal
Laminar
32
What type of flow is:
| Cross mixing, Vibrational noise, Least efficient, and frequently associated with vessel disease (bruit)
Turbulent
33
What is a probability statement for turbulent flow
Reynold's number
34
T/F: The greater the R#, the greater the probability for turbulence
True
35
What kind of flow is it if R#
Laminar
36
What kind of flow is if if R# > 3000
Turbulent
37
What can be used to determine velocity of flow
Ultrasound
38
What kind of band is associated with turbulent flow
Broad band
39
What kind of band is associated with laminar flow
Narrow band
40
What does the Fick Principal apply to
Blood flow to a tissue/organ
41
What are the 3 ports of the Fick principal
Input/Output blood concentration of substance x and Add/Remove of substance x from tissue
42
What is the ability of a vessel to stretch
Distensibility
43
What is the ability of a vessel to stretch and hold volume
Compliance
44
In systemic arteries a small change in volume is associated with what
a Large change in pressure
45
In systemic veins a large change in volume is associated with what
a Small change in pressure
46
T/F: Veins are about 8x more distensible and 24x more compliant than systemic arteries
True
47
What is local blood flow regulated in proportion to
The metabolic demand in most tissues
48
What is used for short term control of blood flow
Vasodilation and vasoconstriction of precapillary resistance vessels
49
What is used for long term control
Changes in tissue vascularity
| Vascular endothelial growth factor and angiogenin
50
What act as integrator of multiple inputs
Arterioles
51
What are arterioles richly innervated by and what kind of receptors do they have
SNS vasoconstrictor fibers
| Alpha receptors
52
T/F: Arterioles are not effected by local factors (vasodilators, circulating substances)
FALSE they ARE effected
53
What theory says active tissue release local vasodilator (metabolites) which relax vascular smooth muscle
Local vasodilator theory
54
What theory is older, and says as tissue uses up oxygen, vascular smooth m. cannot maintain constriction
Oxygen demand theory
55
Adenosine, CO2, adenosine phosphate compounds, histamine, K+ ions, H+ ions, PGE and PGI series prostaglandins, CO and NO are ALL what
Local Vasodilators
56
What is the ability to keep blood flow (F) constant in the face of a changing arterial BP
Autoregulation
57
T/F: Most tissues cannot show some degree of autoregulation
FALSE, Most tissues SHOW some degree of autoregulation
58
What 2 things in the kidney are both autoregulated
Renal flow and Glomerular filtration rate (GFR)
59
What in long term control of flow is an ongoing, day to day reconstruction of the vascular system
Changes in tissue vascularity
60
What in long term control of flow involves the production of new microvessels
Angiogenesis
61
What are angiogenic factors
small peptides stimulate growth of new vessels
| VEGF vascular endo. growth factor
62
What happens if you block angiogenesis in tumors
They cannot grow
63
What does stress activated endothelium up-regulate
Expression of monocyte chemoattractant protein-1 (MCP-1)
64
What does hypoxia cause the release of
VEGF. vascular endo. growth factor
65
What is Mesenchymal cell differentiation into endothelial cells
Vasculogenesis
66
What is the formation of new blood vessels by sprouting from pre-existing small vessels
Angiogenesis
67
What is rapid proliferation of pre-existing collateral vessels with fully developed tunica media
Arteriogenesis
68
What are the 2 mechanical angiogenesis triggers
Hemodynamic
| Shear stress
69
What are the 2 chemical angiogenesis triggers
Hypoxia
| NO
70
What are the 3 molecular angiogenesis triggers
Dec. glucose -> Inc. VEGF
Inflammation
Angiogenic Growth factors
71
What is clinical enhancement/promotion of collateral blood vessels/flow in ischemic tissues
Therapeutic angiogenesis
72
What are the 3 methods of therapeutic angiogenesis
Protein, Gene, Cellular therapies
73
What inhibits platelet aggregation and relaxes vascular smooth muscle
Prostacyclin (PGI2)
74
What is a vasodilator and release is stimulated by shear stress associated with inc. flow and AcH binding to endo.
NO (healthy endothelium)
75
What constricts vascular smooth m. and may contribute to vasoconstriction when endothelium is damaged by hypertension
Endothelin (damaged endothelium)
76
What is the functional unit of microcirculation
Capillary
77
What are the mechanisms of exchange in microcirculation
Diffusion
Ultrafiltration
Vesicular transport
78
What is Functional or Nutritive flow associated with
Inc. oxygen uptake/utilization
79
What is Non nutritive flow increase associated with
Shunting of blood through a bed
80
What does a Hydrostatic P gradient (high to low) favor
Filtration, Capillary HP 17
| Interstitial HP -3
81
What does Colloid Osmotic P (low to high) favor
Reabsorption, Capillary COP 28
| Interstitial COP 9
82
What is colloid osmotic pressure a function of
The protein concentration
83
What is the most abundant plasma protein
Albumin 75%
84
What is the calculated colloid effect vs the actual colloid effect
Calc 19mmHg
| Actual 28mmHg
85
What is the discrepancy between the calculated vs actual colloid effect due to
Donnan Effect
86
What increases the colloid osmotic effect. Large MW plasma proteins carry neg. charges which attracts + ions inc. osmotic effect by ~50%
Donnan Effect
87
Where is an example where capillary walls are tight junctions
Blood brain barrier
88
Where is there a discontinuous capillary wall
Liver capillaries
89
What capillaries in the kidney have filtration slits (fenestrations)
Glomerular capillaries
90
What proteins can exert osmotic pressure
Only those that cannot cross capillary wall
91
What expresses how readily protein can cross capillary wall
Reflection coeffecient
92
What does a RC (reflection coefficient) 0 represent
All colloid proteins freely cross, none reflected, no colloid effect
93
What does a RC of 1 represent
All colloid proteins reflected, none can cross, full colloid effect
94
What drains excess fluid from interstitial spaces
Lymph capillaries
95
Where are not true lymphatic vessels found
Superficial skin, CNS, endomysium of m., & bones
96
What drains the lower body, left side of head, left arm, part of chest
Thoracic duct
97
What drains the right side of head, neck, right arm and part of chest
Right lymph duct
98
What was just discovered in CNS near DVSes
True lymphatic vessels
99
What does perivascular spaces contain and what does it communicate with
Contains CSF and communicates with subarachnoid space
100
What acts as a functional lymph system in CNS
Arachnoid villi
101
What does excess plasma filtrate resemble
Interstitial fluid from the tissue it drains
102
Where does 2/3 of all lymph come from
Liver and intestines
103
Any factor that inc. filtration and/or dec. reapsorption will do what to lymph formation
Inc. lymph formation
104
What is the rate of flow for the Thoracic duct
100 ml/hr.
105
What is the rate of flow for the Right lymph duct
20 ml/hr.
106
What is the Total lymph flow for a day
2.9 L/day
107
Every day, what is the volume of lymph roughly equal to
Your entire plasma volume is filtered
108
These are characteristic functions of what:
Return lost protein to vascular system
Drain excess plasma filtrate from ISF space
Carry absorbed substances/nutrients (fat-chylomicrons) from GI
Filter lymph (defense function) at lymph nodes
Functions of Lymphatics
109
What are a meshwork of sinuses lined with tissue macrophages (phagocytosis)
Lymph nodes
110
What is created by the interaction of blood with vascular wall
Arterial blood pressure
111
During systole, the left ventricular output (SV) is greater than what
Peripheral runoff
112
Total blood volume rises which causes arterial BP to inc to a peak occurs when
During systole
113
When are the arteries distended
During systole
114
While the left ventricle is filling, the arteries are recoiling, which serves to maintain perfusion to tissue beds occurs when
Diastole
115
TBV in arterial tree is dec., causing arterial BP to fall to a min value is what
Diastolic BP
116
Stretch and recoil refers to what
Systole and diastole
117
What phenomenon converts an intermittent output by the heart to a steady delivery at the tissue beds and saves the hear work
Hydraulic Filtering
118
What happens to hydraulic filtering as we age
Distensibility of the arterial tree dec. reducing hydraulic filtering, inc. the work load on the heart
119
What is the maximum pressure in the systemic arteries
Systolic BP
120
When does Systolic BP pressure peak
As blood is ejected from the left ventricle into the aorta
121
Cycle length (CL) is inversely proportional to what
DBP, Diastolic BP
122
Total peripheral resistance (TPR) is proportional to what
DBP, Diastolic BP
123
During exercise, DBP may not change much due to what
Dec. CL is offset by a dec. in TPR (total peripheral resistance)
124
T/F: The mean arterial pressure (MAP) is not the arithmetical mean between systole and diastole
TRUE
125
1/3 Pulse pressure + DBP equals what
MAP (mean arterial pressure)
126
What substance do most post-ganglionic SNS terminals release
Norepinephrine
127
What is the predominant receptor type dealing with SNS
alpha
128
What is the alpha response
Constriction of smooth m.
129
What does SNS stimulation cause
Widespread vasoconstriction causing dec. blood flow with 3 exceptions
130
What are the 3 exceptions to SNS stimulation
Brain, Heart and Lungs
131
T/F: As arterial pressure falls, there is a critical pressure below which flow ceases due to closure of the arterioles
True
132
What is required to keep arterioles from closing completely
Critical luminal pressure
133
What happens to arterial and venous pressure if cardiac output is stopped
Arterial pressure will fall
| Venous pressure will rise
134
What is Mean circulatory filling pressure
MCFP is equilibration pressure where arterial BP = venous BP
135
What may prevent equilibration pressure
Closure of the arterioles (critical closing pressure)
136
What is responsible for pressure gradient driving peripheral venous return
MCFP (mean circulatory filling pressure)
137
What happens if MCFP=CVP
Venous return goes to 0
138
As CVP (central venous pressure) inc, what happens to cardiac output
Inc. due to both intrinsic and extrinsic effects
139
What is the pressure in the central veins (sup. and inf. vena cava) at the entry into the right atrium
Central Venous Pressure
140
What is Central Venous Pressure equal to
Right atrial pressure
141
What is a collection of neurons in the medulla and pons
Vasomotor center
142
What are the 4 major regions of the vasomotor center
Pressor center
Depressor center
Sensory area
Cardioinhibitory area
143
What region of the vasomotor center mediates the baroreceptor reflex
Sensory area
144
What region of the vasomotor center stimulates CN X
Cardioinhibitory area
145
What vasomotor region from the anterolateral portions of the upper medulla has norepinephrine projections to IML horn cells (pre-gang SNS)
Pressor Center
146
What are the effects of the pressor center
Vasoconstriction
Stim cardiac activity
Tonically active exciting SNS outflow
147
What vasomotor region from the anterolateral lower medulla oblongata inhibits the pressor center
Depressor Center
148
By inhibiting the pressor center, what effects occur
Vasodilation, Dec. cardiac activity
149
What vasomotor region from the posterolateral portions of the pons and medullat in the nucleus tractus solitarius recieives input primarily from CN IX and X
Sensory area
150
The sensory area has outputs to what centers
Both pressor and depressor
151
What is the function of the Sensory area
Mediate the baroreceptor reflex. inhibits pressor center, lowers BP
152
What vasomotor region is located medially next to dorsal motor nucleus of vagus (DMNV) and transmits impulses into DMNV inhibiting heart activity
Cardioinhibitory area
153
What maintains normal arterial BP
Sympathetic vasoconstrictor tone
154
What control of BP involves the nervous systems effect on vascular smooth m.
Rapid short term
155
What control of BP is dominated by the kidneys (body fluid balance)
Long term control
156
How is control of BP accomplished
Either affecting vascular tone or blood volume
157
What are spray type nerve endings in vessel walls
Baroreceptors
158
Where are baroreceptors especially abundant
Carotid Sinus
| Arch of Aorta
159
How are baroreceptors stimulated and what happens when they are stimulated
Stimulated by stretch and they inhibit the pressor center
160
What are the net effects of baroreceptor function
Vasodilation and dec. cardiac output
161
What is more sensitive to changing pressure than static pressure
Carotid sinus reflex
162
When does a buffer change in BP to a change in blood volume
Normal cardiac cycle
163
When does a buffer change in BP due to change in body postition
Lying to standing position
164
What is lack of long term control due to
Adaptation, resetting within 1-2 days
165
Where are low pressure baroreceptor located
Atrial walls and pulmonary arteries
166
What minimize arterial pressure changes in response to blood volume changes
Low pressure baroreceptors
167
What is the Baroreceptor reflex
Low pressure. dec. HR
168
What does the bainbridge relfex do
Increase HR
169
What does Atrial Natriuretic Peptide do
Diruretic, natruiretic, vasodilator
170
What does the renal-body fluid system control
Arterial pressure
171
What will cause AP (arterial pressure) to rise
Inc. ECF. Kidneys excrete excess ECF
172
Will increased total peripheral resistance create a long term elevation of BP if fluid intake and renal function do not change
NO
173
What supply the glomerular capillaries where filtration takes place
Afferent arterioles
174
What drain the glomerular capillaries and give rise to the peritubular capillaries where reabsorption takes place
Efferent arterioles
175
What are specialized peritubular capillaries associated with juxtamedullary nephrons
Vasa recti
176
What happens to the arterial pressure when the ECF levels rise
arterial pressure Rises
177
When arterial pressure rises, what does the kidney do to bring the pressure back to normal
It excretes more fluid
178
What hormones Dec. renal blood flow (RBF)
Norepinephrine
Epinephrine
Angiotensin II
179
What hormones Inc. renal blood flow (RBF)
Prostaglandins E&I
180
What does the Tubuloglomerular feedback monitor
NaCl in the Macula densa of the distal tubule
181
What does a Dec. in NaCl in macula densa cause
Dilation of afferent arteriole
182
What is the source of renin
Smooth m. cells in afferent arteriole (synthesis, storage, release)
183
What stimulates renin
Dec. perfusion pressure
Stim. SNS
Dec NaCl delivery to macula densa
Thyroid and Growth hormone
184
What is the enzyme that catalyses the formation of Angiotensin I (10 AA) from angiotensinogen (liver)
Renin
185
Where does Angiotensin I to Angiotensin II occur
Primarily in the lung via angiotensin converting enzyme
186
What stimulates thirst/drinking behavior at the level of the hypothalamus
Angiotensin II
187
What happens if one renal artery is tied off
Development of systemic hypertension
| No development of uremia
188
What happens if one renal artery is tied off and remove kidney
No development of hypertension or uremia
189
What happens if you tie off and remove both kidneys
Development of both hypertension and uremia
190
What is the Goldblatt hypertensive model
Hypertension generated by tying off a renal artery
191
Slow breathing (6/min) does what to arterial baroreflex sensitivity
Inc.
192
NO from the endothelium does what to smooth muscle
Relaxes
193
What is NO rapidly inactivated by
Superoxide radical
194
Glutathione, Melatonin, Superoxide dismutase, Beta-carotene, Lutein, Lycopene, Selenium, Vit. A, C, E are all what
Antioxidants
195
What may act at the CNS to inhibit reflex SNS activation
Serotonin
196
What may act centrally to inhibit sympathetic nerve activity
NO
197
What may promote bradycardia and hypotension
Serotonin and NO
198
What type of blood flow is minimal in the fetus
Pulmonary
199
What supplies blood flow to the placenta
The umbilical arteries, a branch off the anterior iliac arteries
200
How does blood return to the fetus from the placenta
Umbilical vein
201
What allow blood to bypass lungs
Ductus arteriosis
| Foramen ovale
202
What allows the umbilical and portal blood to bypass the liver
Ductus venosus
203
What have the greatest Oxygen saturation in fetal blood
Umbilical vein 80%
IVC 67%
Aorta 62%
Umbilical arteries 58%
204
What circulatory readjustments occur at birth
Increased blood flow through lungs and liver AND Loss of blood flow through the placenta
205
Closure of what causes the circulatory readjustments at birth
Foramen ovale, Ductus Arteriosis and Ductus Venosus
206
Closure of what has an unknown cause and allows portal blood to perfuse liver sinuses
Ductus Venosus
207
What shunts most blood returning to the heart from the IVC to the left atrium
Foramen Ovale
208
What shunts most blood returning to the heart from the SVC to the aorta
Ductus Arteriosus
209
What is the greatest stress on the CV system
Exercise
210
What orchestrates many of the changes associated with exercise
SNS
211
How much is CO increased during exercise
5-6 fold
212
Where is blood flow shifted from and to
From organs to skeletal m.
213
What is Venous Pump
Intermittent skeletal m. activity coupled with one way valves in veins. primarily in LE
214
What does inc. frequency and depth of respiration do to cyclic neg. thoracic pressure
Increased
215
What is increased blood flow to active m. mediated by
Local release of tissue metabolites
216
Adenosine, CO2, K+, Histamine, Lactic acid are all what
Local vasodilators
217
What is CO at rest
5.9 L/min
218
What is CO during exercise
24 L/min
219
What is the maximum volume of oxygen that one can take up from the lungs and deliver to the tissues/minute
VO2 max
220
VO2 in cardiac patient, Sedentary man, endurance athlete
1.5 L/min, 3.0 L/min, 6.0 L/min
221
What happens if energy demands of exercise cannot be met by oxidative phosphorylation
O2 debt occurs
222
What is the extra O2 used for when repaying the oxygen debt
Restore metabolite levels
| Metabolize lactate generated by glycolysis
223
What is the O2 debt equal to
Engergy consumed during exercise
