Unit 2 Circulation Flashcards
1
Q
What is the purpose of the circulatory system
A
Deliver O2 to systemic tissue
Deliver nutrients to tissues
Remove CO2 and waste from systemic tissues
Transport hormones
2
Q
What are the functional parts of the circulatory system
A
Arteries Arterioles Pre-capillary sphincters Capillaries Venules Systemic veins
3
Q
What functional part of the circulatory system is under the most pressure
A
Arteries
4
Q
T/F: Arterial pressure control is dependent of local flow or cardiac output
A
False
Arterial pressure control is independent of local or cadiac output
5
Q
What is cardiac out put controlled by
A
Local tissue flow
6
Q
What is blood flow in proportion to
A
Metabolic rate
7
Q
What is different between the aorta and a normal artery in tissue composition
A
Aorta has mainly Elastic and fibrous tissue with some smooth mucle
Arteries have mainly Elastic tissue and smooth muscle with some Fibrous tissue
8
Q
What is the typical tissue composition of a vein
A
Equal parts elastic, fibrous and smooth mucle
9
Q
What type of tissue composes capillaries
A
Only endothelium
10
Q
What is the name for the volume of blood that passes a certain point per unit time
A
Flow
11
Q
What is the driving force of blood flow
A
Pressure gradient
12
Q
Where is the greatest resistance to flow found
A
In the pre-capillary vessels
13
Q
T/F: At a given F, if the pressure decreases the resistance decreases
A
False
At a given F, if the pressure decreases the resistance increases
14
Q
What are the advantages of Parallel circuitry
A
Independence of local flow control
Minimize total peripheral resistance
O2 rich blood to all tissue
15
Q
What is the internal friction of a fluid
A
Viscosity
16
Q
What happens to velocity with viscosity incrases
A
Velocity decreases
17
Q
What happens to apparent viscosity when cells get stuck
A
Apparent viscosity increases
18
Q
What fiber pervents RBC’s from getting stuck
A
Fibrinogen
19
Q
How do RBC decreases viscosity in small vessesl
A
They line up
20
Q
What is the normal range of RBC’s in blood
A
38-45%
21
Q
What type of flow is associated with Vessel disease
A
Turbulent flow
22
Q
What is Reynold’s number
A
Probability statement for turbulent flow
23
Q
What tool is used to determine velocity of flow
A
Doppler Ultrasonic Flow-meter
24
Q
What indicated turbulent flow with a dopler ultraconic flow-meter
A
Broad band
25
What indicates Laminar flow with a doppler ultrasonic flow-meter
Narrow band
26
What determines cardiac output
Flick principal
| Indicator dilution
27
What determines vessel flow
Venous occlusions
Doppler ultrasonic flow meter
Vascular flow cuffs
28
What is fick principal
Blood flow to a tissue organ
29
What is the ability of a vessel to stretch
Distensibility
30
What is the ability of a vessel to stretch and hold volume
Compliance
31
A small change in volume in an artery will result in what
A large change in pressure
32
A large change in volume in a vein will result in what
A small change in pressure
33
How much more distensible and compliant are veins than arteries
Distensible = 8x
Compliant 24x
34
How is blood controlled in the short term
Vasodilation
| Vasoconstriction
35
What can affect arteriols on whether they constrict of dilate
SNS innervation constriction fibers
| Local dilators
36
What causes arterioles to dilate
Vasodilators
CO, NO
decrease O2
37
What happens to resistance and flow when an arteriol is dilated
Resistance decreases
| Flow Increases
38
What happens to resistance and flow when an arteriol is Constricted
Resistance Increases
| Flow Decreases
39
What are the two theories involved in Vasodilation
Local Vasocilator theory
| Oxygen demand theory
40
What are Local Vasodilators
```
Adenosine
Carbon dioxide
Adenosine phosphate
Histamine
Potassium
Hydrogen
Prostaglandins
```
41
What is the ability to keep blood flow constant in the face of a changing arterial BP
Autoregulation
42
What causes Arteriogenesis
Stress caused by enhanced blood flow
43
What is VEGF
Vascular endothelial growth factor (promotes angiogenesis)
44
What up regulates expression of MCP-1
Stress activated endothelium
45
What happens when MCP-1 is expressed in blood vessesl
Increase in the number of Monocytes in vessels
Inflammation
Remodeling/development of arteries
46
What does Hypoxia cause the release of
VEGF
47
What is important in development of collateral arterial vessels
VEGF
48
What was VEGF first isolated from
Tumors
49
Terms used to describe Mesenchymal cell differentiate into endothelial cells
Vasculogenesis
50
Term used to describe formation of new blood vessles by sprouting from pre existing small vessels
Angiogenesis
51
Term used to describe repid proliferation of pre-existing collateral vessels with fully developed tunica media
Arteriogenesis
52
What are the different methods in therapeutic angiogenesis
Protein therapy
Gene therapy
Cellular therapy
53
What can endothelium release to affect Blood vessels
Release Prostacylin
Release NO
release Endothelin
54
What does Prostacyclin do
Inhibit platelet aggregation
| Relaxes vascular smooth muscle
55
What does NO do
Vasodilator
56
What stimulates the release of NO
Shear stress
| Acetylcholine binding to epithelium
57
What does Endothelin do
Vasoconstrictor
58
What is the functional unit of circulation
Capillary
59
What are the mechanisms of exchange in microcirculation
Diffusion
Ultrafiltration
Vesicular transport
60
What is functional flow
Increased oxygen uptake/utilization
61
What is non functional flow
Non nutritive flow, associated with shunting of blood through a bed
62
What is Ultrafiltration
Bulk flow through a capillary wall
63
What favours filtartion
hydrostatic pressure gradient (high to Low)
64
What favours reabsorption
Colloid osmotic pressure (low to High)
65
What impacts the amount of Colloid osmotic pressure
The concentration of proteins in plasma
66
What is the Donnan Effect
Increases the colloid osmotic effect
67
What causes the Donnan effect
Large plasma proteins carry negative charges that attract ions, increasing osmotic effect
68
T/F: ALL plasma proteins account for Osmotic pressure
False
Only protein that can't cross capillary wall can exert osmotic pressure
69
What is the reflection coefficient
How readily protein can cross capillary wall
70
What drains excess fluid from interstitial spaces
Lymph capillaries
71
Are there true lymphatics in the CNS
no
72
What acts as a functional lymphatic system in the CNS
Arachnoid vili which empties into dural venous sinuses
73
Where does most of the lymph come from
Liver and intestines
74
Factors that increase filtration and/or decrease reabsorption will do what to lymph
Increase lymph formation
75
What is the rate of lymph flow per hour
120ml/hr (2.9L/day)
76
every day the volume of lymph is ____ to your Entire plasma volume is filtered
Equal
77
What are the functions of Lymphatics
Return lost protein in vascular system
Drain excess plasma
Carry nutrients
Filter lymphatics
78
What creates arterial blood pressure
The interaction of blood with vascular wall
79
When are arteries distended
During systole = blood pumped out = Systolic BP
80
What is Diastolic BP
The lowest point that BP falls during diastole
81
What is Hydraulic Filtering
Phenomenon that converts intermittent output by the heart into a steady flow to tissues using distensibility of arterial tree
82
When is inflow rate to the LV the fastest
Systole
83
What determines the Diastolc BP
```
Cycle length (high CL will decrease DBP)
Total peripheral resistance (proportional to DBP)
```
84
Does DBP chance during exercise
No because cycle length is offset by total peripheral resistance
85
What is the predominant Norepinephrine receptor in blood vessels
Alpha receptors
86
What affect does SNS have on blood flow
Decreases flow
87
SNS stimulation decreases blood flow exept where
Brain
Lungs
Heart
88
How does the heart prevent decreased blood flow due to SNS activation
Increase of Cardiac activity, which releases vasodilators (adenosine)
89
How does the Brain and Lungs avoid the affects of SNS stimulation on Vasoconstriction
They arteriols are weakly innervated by SNS
90
What is the Critical closing pressure
The pressure that causes arterioles to close
91
What keeps arterioles from closing
Critical luminal pressure
92
What is Mean circulatory filling pressure
the point when arterial BP is equal to venous BP
93
What prevents Equilibration of pressure
Closing of arterioles
94
What happens as Central venous pressure increases
Venous return decreases
95
What is Central venous pressure
Pressure in Superior and Inferior vena cava when it enters right atrium
96
Central venous pressure is equal to what (can also be called)
Right atrial pressure
97
What is the collection of neurons in the medulla and pons
Vasomotor center
98
What does the pressor center do in the vasomotor center
Increases blood flow
Vasoconstriction
Increase cardiac activity
99
What does the depressor center do in the vasomotor center
Decrease blood pressure
Vasodilation
Decrease cardiac activity
100
What does the Sensory area do in the vasomotor center
Mediates baroreceptor reflex (inhibit pressor center = lower BP)
101
What does the cadrioinhibitory area do in the vasomotor center
Stimulates CN X to inhibit heart activity
102
What controls blood pressure
Nervous system effects on smooth muscle
| Renal-body fluid balance
103
Where are baroreceptors abundant
Carotid Sinus
| Arch of Aorta
104
What happens when Baroreceptors are streched
Vasodilation
| Decreased Cardiac Output
105
What CN send Baroreceptive info to the CNS
IX X
106
Where are Low pressure barorecptors located
Atrial walls
| Pulmonary arteries
107
How do the kidneys control BP, why triggers this
Increased ECF will cause AP to rise
Kidney excrete excess ECF
108
Will increased total peripheral resistance create a long term elevation of BP assuming no change in fluid intake and renal change
No
109
What type of arteriols drain glomerular capillaries
Efferent
110
Where does reabsorption take place
Peritubular Capillaries
111
Where does filtration take place in the kidneys
Afferent Arterioles
112
What hormones decrease renal blood flow
Norepinephrine
Epinephrine
Angiotensin II
113
What hormones increase renal blood flow
Prostaglandins
114
What monitors NaCl in the distal tubule
Macula densa
115
What is released when the Macula densa senses a decrease in NaCl
Juxtaglomerular cells release Renin
116
What does Renin do
Catalyses the formation of angoitensin
117
What is the function of Angiotensin II
Stimulates adrenal cortex to secrete aldosterone
Stimulate Kidney
Stimulate release of ADH
118
What is the net effect of angiotensin
decrease Na+H2O secretions = increase BP
119
What does slow breathing do to the Baroreflex
increase arterial baroreflex sensitivity
120
What does NO do to smooth muscle
Relaxes it
121
What inactivates NO
Superoxide redical
122
What does Increasing Antioxidents do to NO
reduced amount of free radicals, allowing NO to last longer lower BP
123
What humoral substances can cause hypotension and bradycardia
Serotonin
| NO
124
What are the Three shunts in fetal circulation
Ductus arteriosis
Foramen ovale
Ductus Venosus
125
What shunts allow fetal blood to bypass the lungs
Ductus arteriosis
| Foramen ovale
126
What shunt allows fetal blood to bypass the liver
Ductus Venosus
127
What changes happen to circulation after birth
Increase blood flow to liver and lungs
Decrease pulmonary vascular resistance
Decreased RVP
Decreased Pulmonary BP
128
What causes the closure of the Foramen ovale
Reversal in pressure gradient closes flap
129
What causes the closure of Ductus Arteriosis
Reversal of flow
| increased O2 cause muscle constriction
130
What causes the closure of the ductus Venosus
Not known
