Exam 2 Flashcards
1
Q
What circulatory structures acts as a control valve to regulate flow?
A
Arterioles and pre capillary sphincters
2
Q
T/F: Pulmonary blood flow=venous return=cardiac output
A
True
3
Q
What 4 histologic materials are vessels made of?
A
Endothelium
Elastic tissue
Smooth muscle
Fibrous tissue
4
Q
What tissue is most prominant in the aorta?
A
Elastic, (then fibrous, then smooth muscle)
5
Q
In a typical artery, what tissue type dominates?
A
Smooth muscle (then elastic, then fibrous)
6
Q
What structure is only made of endothelium?
A
Capillaries
7
Q
The volume of blood that passes a certain point per unit time is what?
A
Flow rate
8
Q
At a given flow, the velocity is ________ to the cross-sectional area of a vessel.
A
Inversely proportional
9
Q
What is the only organ to have flow in excess to the cardiac output (CO)?
A
Lungs
10
Q
Flow is ___ to change in pressure but ____ to resistance.
A
Proportional to chg P, but inversely proportional to resistance
11
Q
What is considered the driving force of blood movement.?
A
Pressure gradient
12
Q
Systemic circulation is predominantly a ____circuit? Series, parallel, or series¶llel?
A
Parallel
13
Q
3 advantages of a parallel circuitry?
A
- Incr/decr flow to tissues independently
- Lowers total peripheral resistance (TPR)
- Oxygen rich blood to every tissue
14
Q
Slower blood flow is associated with an increase or decrease in blood viscosity?
A
Increase
15
Q
What increases the flexibility of RBC’s?
A
Fibrinogen
16
Q
What is the normal range for hematocrit?
A
38%-45%
17
Q
What disorder is associated with less than 38% hematocrit?
A
Anemia
18
Q
T/F: Both EPO and exercise stimulate RBC production
A
True
19
Q
What part of a vessel has the fastest velocity?
A
The center of the vessel
20
Q
What is the normal, silent, and efficient type of flow called?
A
Laminar flow
21
Q
How does Turbulent flow differ from Laminar flow?
A
Turbulent is less efficient, creates vibrational noise, and is associated with vessel dz
22
Q
What location in the circulatory system is most likely to have turbulent flow?
A
Aorta
23
Q
If the Reynold’s # (R#) is less than 2000 flow is ____, and if the R# is greater than 3000 flow is ___.
A
3000=turbulent
24
Q
What is the only factor that is inversely proportional to Reynold’s #: velocity, viscosity, diameter, density
A
Viscosity, (all others are proportional)
25
T/F: Broad band Doppler reading is associated with laminar flow
False: Broad=turbulent...Narrow=laminar
26
T/F: Fick principal is associated with determination of cardiac output
True
27
What is distensibility?
the ability of a vessel to stretch
28
How is compliance different from distensibility?
Compliance is the ability of a vessel to stretch AND hold volume
29
Which is more compliant: arteries or veins?
Veins...arteries can't store much blood
30
T/F: In systemic arteries, a small change in volume is associated with a small change in pressure?
False: small change in volume-->large change in pressure
31
In systemic veins, a large change in volume is associated with a ___ change in pressure
small
32
Veins are 8 times more ____ and 24 times more ____ than systemic arteries.
Distensible, compliant
33
T/F: The more wall tone present, the more distensible a vessel will be
False, incr wall tone--> decr in compliance and distensibility
34
What is the determining factor of local blood flow to tissues?
Metabolic demand by tissues (more active tissues, more blood flow)
35
T/F: A method of short term control of blood flow includes vasodilation/vasoconstriction of arterioles
True
36
What is the long-term control of blood flow solution?
Change tissue vascularity via angiogenesis
37
Two factors important in long term control of blood flow?
1. Vascular Endothelial Growth Factor
| 2. Angiogenin
38
T/F: SNS vasoconstrictors have alpha receptors
True
39
What is the local vasodilator theory?
Active tissues release local vasodilators that relax vascular smooth muscle
40
What is the older theory regarding local vasodilation?
Oxygen Demand Theory; tissues use up oxygen and can't maintain vasoconstriction and defaults to vasodilation
41
What is the flaw with the Oxygen Demand Theory?
Tissues on the upstream end would theoretically never vasodilate b/c they have a surplus of oxygen
42
T/F: Adenosine, NO, CO2, and Histamine are all examples of local vasodilators
True
43
What is the important concept regarding angiogenesis and cancer growth?
If we could block tumors block supply by inhibiting angiogenesis, we could ideally choke off the tumor
44
What is the up-regulation of monocyte-chemoattractant protein-1 (MCP-1) associated with?
Following stress to endothelium-->attraction of monocytes-->inflammation and eventual angiogenesis
45
Hypoxia stimulates the release of ______factor, regarding potential angiogenesis.
Vascular Endothelial Growth Factor (VEGF)
46
T/F: Neuropeptide Y from parasympathetic nervous system is angiogenic
False: NPY is from SNS to enable angiogenesis
47
What is vasculogenesis?
development of NEW blood vessels from mesenchyme cells
48
What is the big difference between angiogenesis and arteriogenesis?
Both sprout from pre-existing vessels but arteriogenesis have fully developed tunica media whereas angiogenesis usually lacks the developed tunica media
49
3 methods of therapeutic angiogenesis?
```
Protein Therapy (GF proteins)
Gene Therapy (manipulate gene expression)
Cellular Therapy (cells that produce angiogenic factors introduced to ischemic tissue)
```
50
T/F: Prostacyclin promotes platelet aggreggation
False: promotes vasodilation and inhibits platelet aggreggation
51
In response to shear stress, healthy endothelium releases ___, which acts as a vasodilator.
Nitric Oxide (NO)
52
What is the vasoconstrictor released by damaged endothelium?
Endothelin
53
What is the functional unit of the circulatory system?
Capillary
54
What is the intermittent contraction of metarterioles and pre capillary sphincters called?
Vasomotion
55
Functional flow is associated with an increased ____?
oxygen uptake
56
T/F: Non-nutritive flow increases are associated with shunting of blood thru a bed
True
57
Starling forces consist are responsible for ultrafiltration by the means of which two pressure?
Hydrostatic P and Colloid Osmotic P
58
What type of molecules do capillaries utilize passive diffusion for?
Gases that meet permeability and concentration gradient standards use passive diffusion
59
Hydrostatic P gradient favors ___, whiles colloid osmotic P favors ___.
Hydrostatic-filtration (pushes fluid out)
| Colloid Osmotic-reabsorption (draw fluid back in)
60
T/F: Generally filtration rate=reabsorption rate
False: Filtration>Reabsorption
61
If filtration is more than reabsorption, why do we not end up with permanent edema?
Lymphatics manage the excess fluid pushed out of a vessel
62
What are the 3 main plasma proteins that assist with colloid osmotic pressure gradient?
Albumin (75%)
Globulins (25%)
Fibrinogen (<1%)
63
What is the Donnan Effect?
Increases colloid osmotic effect b/c large MW, negatively-charged plasma proteins attracting positive ions
64
How much does the Donnan Effect increase the osmotic effect?
Increases by about 50%
65
Where in the body would you find tight junctions on capillary wall? Discontinuous capillary walls? Fenestrated capillary walls?
Tight Junction=blood brain barrier
Discontinuous=liver
Fenestrations=glomerular capillaries of kidneys
66
T/F: Only proteins that cannot cross the capillary wall can exert osmotic pressure
True
67
What would a reflection coefficient of 0 mean?
Proteins can readily cross capillary=no colloid effect
68
Where in the body would the reflection coefficient be equal to 1?
Brain; all proteins reflected in capillary=full colloid effect
69
T/F: There are no true lymphatics found in the superficial portions of skin
True: also none in CNS, bone, or endomysium of muscle
70
What portion of the body does the right lymph duct drain? What drains the rest?
Right side of head, neck, and chest, and right arm. All else is thoracic duct's responsibility
71
What acts as the functional lymphatic system in CNS?
Perivascular spaces accumulate filtrate and send to dural venous sinuses via the arachnoid villi
72
Where is 2/3 of all lymph derived from?
Liver and intestines
73
T/F: Any factor that decreases filtration and increases reabsorption will increase lymph formation
False: INCR filtration and/or DECR reabsorption-->incr lymph formation
74
What are lymph nodes?
Meshwork of sinuses lined with tissue macrophages serving as a defense function
75
What is arterial blood pressure equal to?
volume of blood interacting with the wall
| or (Art BP=CO-TPR)
76
T/F: Greater that half of Total Peripheral Resistance (TPR) is at the level of the capillaries
False: ...at the level of the systemic arterioles
77
T/F: During systole, the left ventricular output is greater than peripheral runoff
True
78
T/F: Falling systolic pressure during exercise is an ominous sign
True
79
The recoil of arteries during ____ can act as a pump.
Diastole
80
What is the phenomenon that converts an intermittent output by the heart to a steady delivery to the tissue?
Hydraulic filtering, (stretch of arteries during systole followed by the recoil during diastole)
81
T/F: As age increases, hydraulic filtering decreases
True--> increased work load on the heart
82
What is the maximum pressure in the systemic arteries?
Systolic Blood Pressure
83
What 2 factors does diastolic BP depend on?
Cycle Length (CL) and Total Peripheral Resistance (TPR)
84
Cycle length is_____ to diastolic BP, and TPR is ____to diastolic BP.
CL inversely proportional to DBP
| TPR is proportional to DBP
85
During exercise, DBP may not change much due to ___CL being offset by ___ in TPR.
Decreased CL, Decreased TPR
86
If exercising and DBP increases, what factor is dominant?
| And if DBP decreases?
Cycle Length dominant if DBP incr
| TPR dominant if DBP decr
87
Most post-ganglionic SNS terminals release what?
Norepinephrine
88
What's the primary receptor type for vascular smooth muscle: alpha, beta, gamma, delta?
Alpha
89
T/F: Constriction of arterioles helps reduce blood flow and raise arteriole blood pressure
True
90
What does constriction of veins do?
Mobilizes blood volume and increases venous return
91
SNS stimulation causes widespread vasoconstriction to everywhere except?
Brain, Lungs, Heart
92
Why does the heart not vasoconstrict upon SNS stimulation?
overridden by local vasodilators such as adenosine
93
T/F: Brain and lungs receive only PNS stimulation
False: still weakly innervated by SNS
94
What is the pressure below which flow ceases due to closure of arterioles: mean arterial BP, mean circulatory filling pressure, critical closing pressure?
Critical closing pressure
95
T/F: An increase in wall tone will increase critical closing pressure
True
96
If cardiac output stopped, arterial pressure will __, and venous pressure will __.
ABP will fall, VBP will rise
97
T/F: if MCFP=Central Venous Pressure(CVP), then venous return goes to 0
True
98
If central venous pressure increases, what happens to cardiac output?
Cardiac output increases
99
A vascular function curve is comparing what two features?
Venous return to central venous pressure (inversely-proportional relationship)
100
A cardiac function curve is comparing what two features?
Cardiac output to central venous pressure (proportional relationship)
101
Where would you measure central venous pressure?
Right atrium
102
T/F: The pressor center and the depressor center increase and decrease your blood pressure respectively.
True
103
What does the sensory area of your vasomotor center mediate?
mediates baroreceptor reflex
104
T/F: The cardioinhibitory area of the vasomotor center stimulates the phrenic nerve exclusively
False: stimulates Vagus Nerve (CNX)
105
T/F: Increased baroreceptor input, increases SNS output
False: decreases SNS output
106
Where is the pressor center and what does it cause?
anterolateral portion of upper medulla;
| vasoconstriction and incr heart activity
107
Where is the depressor center?
anterolateral portion of LOWER medulla
108
Where is the sensory area of the vasomotor center?
Nucleus tractus solitaries of posterolateral portions of pons and medulla
109
What 2 cranial nerves does the sensory area of the vasomotor center receive input from? Outputs to?
CN IX and CN X=input
| pressor and depressor center=output
110
Where is the cardioinhibitory area?
medially next to dorsal motor nucleus of vagus
111
What's considered the long term regulator of blood pressure?
Kidney's system of renal-body fluid balance
112
Where are baroreceptors especially abundant?
Carotid sinus
| Arch of aorta
113
Where do you find low pressure baroreceptors?
Atrial wall
| Pulmonary arteries
114
T/F: You could increase urine output as a way of lowering blood pressure
True
115
What does the Bainbridge reflex do?
Increases heart rate
116
T/F: Atrial Natriuretic Peptide (ANP) is a dirurectic, natriuretic, and a vasodilator
True
117
Which arterioles of the kidney supply the glomerular capillaries: afferent or efferent?
Afferent supply GC, efferent drain GC
118
What is the structure capable of concentrating urine?
Juxtamedullary nephrons
119
Most autoregulation of the kidney occurs at the ___arterioles.
afferent arterioles
120
T/F: Constriction of efferent arterioles will decrease both renal filtration and glomerular filtration
False: ...will decrease renal F but will INCREASE glomerular F b/c of back pressure
121
Normally, do we want an acute or a chronic renal output curve?
Chronic
122
Who is more likely to have an acute renal output curve?
People w/ impaired kidney function
123
Most elements of the chronic renal output curve work to lower blood pressure except ___ which promotes fluid and sodium loss to raise blood pressure.
Atrial Natriuretic Peptide (ANP)
124
What 3 'hormones' decrease renal blood flow via vasoconstriction?
Norepinephrine
Epinephrine
Angiotensin II
125
Prostaglandins do what to renal blood flow?
Increase RBF by vasodilating smooth muscle
126
Decreased NaCl in macula densa of distal tubule, causes what 2 thing?
1. stim renin release from juxtaglomerular cells (constrict efferent arterioles)
2. dilation of afferent arterioles
127
The combination of constricting efferent arterioles yet dilating afferent arterioles promotes what?
Filtration of kidney
128
What is the major source of renin?
Smooth muscle cells in afferent arteriole
129
T/F: Thyroid hormone secretion will decrease renin
False: Stimulates renin
130
Describe Renin-Angiotensin-Aldosterone System?
Angiotensinogen from liver forms Angiotensin I (via renin).
| Angiotensin I--> Angiotensin II (via angiotensin converting enzyme)
131
What does angiotensin II stimulate?
1. release of aldosterone from adrenal cortex
2. release of ADH/vasopressin from post-pituitary
3. stim kidney
(overall effect of increasing BP)
132
T/F: Angiotensin I stimulates thirst/drinking behavior at the level of they hypothalamus
False: Angiotensin II
133
T/F: if you tie off 1 renal artery, you will develop systemic hypertension but don't develop uremia
True
134
T/F: if you tie off one renal artery and remove kidney, don't develop hypertension or uremia
True
135
What would cause one to develop both hypertension and uremia?
Tie off and removal of both kidneys
136
What is the name for hypertension developed due to the tying off of a renal artery?
Goldblatt hypertensive model
137
Does slow breathing play a role in BP control?
Yes, slow breathing--> decrease in both syst BP and diast BP
138
How do antioxidants play a role in lowering BP?
Antioxidants bind to superoxide radical preventing it from inactivating nitric oxide, (a vasodilator)
139
____ and ____ are humoral substances that promote bradycardia and hypotension by inhibiting SNS activity.
Serotonin and Nitric Oxide
140
What is the site of gas exchange in a fetus?
Placenta
141
Blood returns to the fetus from the placenta via what?
Umbilical veins
142
What are the 2 means of bypassing the lungs in a fetus?
Ductus Arteriosus and Foramen Ovale
143
The ductus arteriosus shunts blood from the ___ ___ to the ____.
Pulmonary trunk-->DA-->aorta
144
T/F: The ductus venosus shunts blood from the right atrium to the left atrium
False, that would be the foramen ovale
145
What is the ductus venosus?
Shunts blood past liver;
| Umbilical vein/portal vein-->DV--> Inferior Vena Cava
146
T/F: Umbilical veins operate at 80% oxygen saturation, a much lower value than normal
True
147
What causes the closure of the foramen ovale?
reversal of pressure gradient between RA and LA
148
T/F: Closure of the ductus arteriosus is due to a reversal of flow from aorta to inferior vena cava
False: ..flow from aorta to PULMONARY ARTERY
149
A left to right shunt, flowing from aorta to pulmonary trunk, creating a machinery murmur is called what?
Patent Ductus Arteriosus
150
What is a ventricular septal defect?
membranous septum separating ventricles is not fully formed
151
What is a transposition of great vessels?
RV-->systemic
| LV-->lung
152
How could a transposition of great vessels be fixed?
Create a ventricular septal defect, so blood could flow freely between ventricles
153
4 factors of Tetrology of Fallot?
1. RV hypertrophy
2. Large Ventricular Septal Defect
3. RV outflow obstruction
4. Overriding aorta
154
2 symptoms seen in children with Tetrology of Fallot?
1. Cyanosis
| 2. Dyspnea relieved by squatting
155
___ is the greatest stress you can put on the CV system.
Exercise
156
T/F: During exercise, blood flow is shifted to active skeletal muscle
True
157
Why would SNS stimulation vasoconstrict veins?
Incr MCFP and incr venous return
158
T/F: TPR increases due to vasodilation in active muscle during exercise
False: vasodilation causes TPR decrease
159
T/F: Exercise--> Incr O2 uptake-->decreased VO2--> incr AVO2 difference
True
160
Does SNS affect both SV and HR or only one of the above?
SNS increases both
161
What is Pulse Pressure?
Pulse Pressure= Sys BP- Diast BP
162
What is the "venous pump" utilized during exercise?
Skeletal muscle of lower extremities contract pushing blood upstream and can't flow back down with gravity b/c of presence of valves
163
How does active muscle escape system-wide vasoconstriction of SNS?
Local vasodilators like adenosine, CO2, K+, Histamine, and Lactic acid
164
Conditioning your body results in increased ____ ____.
Stroke volume
165
Respiration remains high post-exercise; what is this extra O2 used for?
Restore metabolite levels, and metabolize lactate generated by glycolysis
166
What system is utilized during the first 10 seconds of exercise?
Phosphocreatine-Creatine System
