Chapter 10 - Vascular Physiology Flashcards
1
Q
What organ has consistent blood flow
A
The brain
2
Q
Top three organs supplied blood at rest (other than brain)
A
-digestive system
-kidneys
-skin
3
Q
Cardiac output calculations
A
Stroke volume x heart rate (b/min)
4
Q
Blood flow depends on
A
Pressure and resistance
5
Q
Flow rate calculations
A
F = (change in) P / R
6
Q
What does F stand for
A
Flow rate
7
Q
What is flow rate?
A
Volume of blood passing thru vessels
8
Q
What does (change in) P
A
Pressure gradient (difference in pressure)
9
Q
what does R stand for
A
Resistance of blood vessels
10
Q
What is the pressure gradient
A
Difference between the beginning and end of a vessel
11
Q
Blood flows from area of
A
High pressure to low pressure
12
Q
What is resistance
A
The measure of opposition of blood flow thru a vessel
13
Q
Resistance depends on
A
-blood viscosity
-vessel length
-vessel radius
14
Q
High blood viscosity equals
A
High resistance
15
Q
Higher length of blood vessels equals
A
High resistance
16
Q
Larger vessel radius equals
A
Lower resistance
17
Q
Greater the friction the
A
Greater the viscosity
18
Q
Blood viscosity is determined by
A
Number of RBC
19
Q
R is proportional to
A
1/r^4
20
Q
How would i solve for (change in) pressure
A
F x R
21
Q
Two functions of arteries
A
-rapid transit with little resistance
-pressure reservoir
22
Q
Arterial connective tissue
A
-collagen
-elastin
23
Q
Function of collagen fibres in arteries
A
Provide tensile strength
24
Q
Elastin fibres function in arteries
A
Provide elasticity
-stretch
-recoil
25
Function of pressure reservoirs
Allows blood flow to be continuous during diastole
26
pressure reservoirs function during systole
Storage as arteries stretch
27
Function of pressure reservoirs during diastole
Keeps pressure to drive the blood even without the active pump of the heart
28
Systole vs diastole
Systole- heart contracting and emptying
Diastole -heart relaxation and filling
29
What is pulse
Stretch of arteries
30
Blood pressure definition
Force exerted by blood against a vessel wall
31
Blood pressure depends on
-volume of blood
-compliance of vessel walls
32
compliance means
How stretchable
33
Higher compliance means
Higher ability to stretch
34
Systolic blood pressure (definition and number)
Peak pressure exerted during cardiac systole
-120 mm Hg
35
Diastolic pressure (definition and number)
Minimum pressure in arteries when blood is draining off into vessels downstream
-80 mm Hg
36
What is pulse pressure
The difference between systolic and diastolic pressure
37
How to calculate pulse pressure
Systolic minus diastolic
(120-80 = 40)
38
Mean arterial pressure is the
Average pressure of driving blood forward
39
How to calculate the mean arterial pressure
Diastolic pressure + (1/3)pulse pressure
40
(Change in) pressure is equal to
Mean arterial pressure
41
Arterials are the
Major resistance vessels
42
Increase in myogenic activity
Vasoconstriction
43
Increase in oxygen is
Vasoconstriction
44
Decrease in sympathetic stimulation
Vasodilation
45
Heat is
Vasodilation
46
Decrease in myogenic activity
Vasodilation
47
Increase in nitric oxide
Vasodilation
48
Decrease in carbon dioxide
Vasoconstriction
49
increase in sympathetic stimulation
Vasoconstriction
50
Increase of carbon dioxide
Vasodilation
51
Histamine release
Vasodilation
52
Cold is
Vasoconstriction
53
Increase in endothelin
Vasoconstriction
54
Increase of resistance by vasoconstriction equals
Flow to decreases
55
Decrease resistance by vasodilation equals
Increased flow
56
When excercing where does blood flow go
Mainly skeletal muscles
-also skin
57
How is organ blood flow adjusted
-intrinsic factors
-extrinsic factors
58
Intrinsic factors
-local chemical influences
-physical influences
59
Chemical influences
-histamine release
60
Physical influences
-heat or cold
-myogenic response
61
Hyperaemia
Increased blood flow to skeletal muscle when body is excess icing or active
62
Local chemical factors that produce relaxation
-decreased O2
-increased CO2
-increased acid (lower pH)
-increased K+
63
Nitric oxide
Causes relaxation of arteriolar smooth muscle
-NO is important in controlling blood flow
64
Extrinsic factors/control
Accomplished by sympathetic nerve influence
65
TPR is
Total peripheral resistance
-all the resistance in the body (mostly the arterials)
66
Norepinephrine influences
Smooth muscle
67
What is the parasympathetic on arterioles
There is NO parasympathetic innervation
68
Sympathetic nerve endings release
NE
69
Where is the cardiovascular control centre
Medulla of brain stem
70
What is the function of the cardiovascular control centre
Blood pressure regulation
71
Higher NE release causes
Higher restriction of vessels
72
What are the hormones that influence arteriolar radius
Epinephrine and norepinephrine
73
Alpha 1 (hormone release and effect on smooth muscle)
-norepinephrine from sympathetic fibres
-causes vasoconstriction
74
Beta 2 (hormone release and effect on smooth muscle)
-epinephrine from the adrenal medulla
-vasodilation
75
Blood viscosity
No change generally, but does effect the TPR
76
What are the two major effectors on arteriolar radius
Local intrinsic control and extrinsic control
77
What effects local controls
Local metabolic changes in 02 and other metabolites
78
What effects extrinsic control
Sympathetic activity
79
Capillaries functions
Exchange of materials
80
The velocity of blood flow though capillaries is
Relatively slow
81
Why is the speed of blood flow so slow in capillaries
To give time for exchange
82
What in capillaries permits the passage of water soluble substances?
Narrow, water filled gaps (pores) found at junctions between cells
83
______ ________ substances readily pass through endothelial cells in capillaries
Lipid soluble
84
How are proteins transported in capillaries
By vesicular transport t
85
Continous endothelium capillary
Small gap/tight junctions
-skin, muscle, bbb
86
Fernestrated capillaries
Larger gaps for filteration
-kidneys, tissues, intestines
87
Sinusoidal capillaries
Largest gaps as it produces a lot of proteins
-incomplete basement membrane
-liver, bone marrow and lymphoid
88
Capillaries: plasma proteins
Generally cannot cross the capillary wall
89
Capillaries: CO2 and O2
Gases can pass through very easily
90
Capillaries: lipid soluble
Pass through the endothelial cells
91
Capillaries: water soluble (small)
Pass through pores
92
Capillaries: proteins
Moved across by vesicular transport
93
The capillary wall is
Semipermeable
94
Active hyperaemia
Dilation due to exercise
95
Two types of passive exchanges
diffusion and bulk flow
96
Diffusion moves across
Concentration gradients
97
Passive diffusion
-no energy spent
-concentration gradient
-no plasma proteins
98
Passive exchanges do not take
-do not take ATP
99
Bulk flow
Fluid exchange between outside and inside
-distributes ECF
100
Bulk force is influence by
Startling forces
101
Startling forces
-capillary blood pressure
-plasma colloid osmotic pressure
102
Capillary blood pressure (hydrostatic)
Force of the fluid on the inside (exerted against a wall)
-pressure forcing outwards
103
Plasma colloid osmotic pressure
Due to plasma proteins
-pushing inwards
-drawing fluid in
104
Capillary blood pressure _____’s plasma colloid osmotic pressure
Opposes
105
Bulk flow is dependent on the difference between
-net hydrostatic pressure
-net colloid osmotic pressure
106
Net pressure of hydrostatic pressure _____ along length of capillary
Decreases
107
What creates colloid osmotic pressure
Plasma proteins
108
Which bulk flow maneuver is low vs very low
-Hydrostatic is very low
-colloid osmotic pressure is very very low
109
Ultra filtration takes place during
Higher hydrostatic pressure and lower osmotic pressure
110
Reabsorption takes place during
Lower hydrostatic pressure and higher osmotic pressure
111
Function of bulk flow
Regulates distribution of ECF
-keeps plasma volume constant e
112
Inward pressure remains
Constant
113
Outward pressure _____ along capillary length
Decreases
114
If BP falls fluid does what
Moves into plasma
115
If BP rises what does fluid do?
Moves into interstitial space
-edema or swelling
116
Blood flow filters and reabsorbed
20L filtered
17L reabsorbed
117
What happens to 3 L during bulk flow?
Lymph
118
Lymphatic system
Fluid returned from interstitial to the blood
119
Lymph
Interstitial fluid that enters a lymphatic vessel
120
Lymph vessels
One way valves, eventually empty into venous system
121
Filteration takes place where in the lymph system
Lymph node
122
Functions of lymph system
-return lymph
-defence against disease
-transport absorbed fat
-return proteins
123
Veins serve as a
Blood reservoir
-store a lot of the blood
124
Increased venous return results in
Increased end diastolic volume, increased stroke volume
-increased cardiac output
125
Frank startling law
The more stretch allows more return of blood
126
How is venous return increased
-Increased sympathies vasoconstrictor activity
-increased skeletal muscle pump
-valves
127
What happens if stroke volume increases
End systolic volume decreases
128
What happens if end diastolic volume increases
-stroke volume increases
-end systolic volume decreases
129
How does venous return increase with increased skeletal muscle?
-since venous pass between muscles, veins are squeezed and sent back quicker
Eg- workout inc venous return
130
Why is blood pressure regulated
-ensure edequate blood flow thru capillaries
131
Blood viscosity is determined by
Number of RBC (which should not change)
132
Baroreceptors function
Detect stretch in arteries
133
Baroreceptors: inc pressure will ____ AP sent to brain
Increase
134
Action potential is measured through frequency or size of action potential?
Frequency
135
Two types of Baroreceptors
-carotid sinus
-aortic arch
136
Increased Baroreceptor equals
Increased frequency of AP
137
Decreased baroreceptor equals
Less frequent
138
Action potential increases when
MAP increases
139
Action potential decreases when
MAP decreases
140
The autonomic nervous system effects what two things
Heart function and blood vessel diameter
141
Parasympathetic impact on cardiovascular system
-only impacts the heart
142
Sympathetic impact on cardiovascular disease
On both vessels and heart
143
Parasympathetic releases ____ to impact the atria
-acetylcholine
144
What does parasympathetic do to the atria/ heart rate
Decreases
145
Sympathetic nerves release ____ into the atria and ventricles
Norepinephrine
146
What does sympathetic do to the atria?
Increase heart rate
147
What does sympathize do to ventricles
More force, higher cardiac output
-increased FOC (force of contraction)
148
Increased FOC leads to
Increased stroke volume
149
Less sympathies/ less NE input would equal what in artery
Dilated
150
More sympathic and NE input does what to vessels
Constricts the vessels
151
Barorecrpots in the ____ sinus and ______ ____ monitor blood pressure
-carotid
-aortic arch
152
Action potentials are conducted by what two nerves?
-glossopharyngeal
-vagus
153
Cardioregulatory and vasomotor cetners are found in the
Medulla oblong at a
154
Decreased parasympathetic increases….
Heart rate
155
Increased sympathic stimulation increases what
Heart rate and stroke volume
156
Increased sympathic stimulation of blood vessels does what
Increases vasoconstriction
157
Everything parasympathetic stimulation does
Dec: HR, CO, BPe
158
Everything sympathic stimulation does
Inc: HR, contractile strength of heart, SV, CO, BP
Inc: vasoconstriction, TPR
Inc: venous return, CO
159
Increased BP signals the
Parasympathetic activity
160
Decreased BP causes
Increased sympathic activity
161
Blood volume is impacted by
-passive bulk flow
-salt and water balance
162
Venous return is impacted by
-blood volume
-skeletal muscle activity
-sympathetic activity and epinephrine
-cardiac suction effect
163
Heart rate is impacted by
-patasympathic
-sympathic activity and epinephrine
164
Stroke volume is impacted by
-sympathic activity and epinephrine
-venous return
165
Cardiac output is impacted by
Heart rate and stroke volume
166
Arteriolar radius is impacted by
-local metabolic control
-extrinsic vasoconstrictor control
167
Blood viscosity is impacted by
Number of RBC
168
Total peripheral resistance is impacted by
-arteriolar radius
-blood viscosity
169
Mean arterial blood pressure is impacted by
-cardiac output
-total peripheral resistance
170
Baroreceptor reflex is primarily a
Short term regulator
-occurs within second
171
If pressure deviates fro more than a few days
There is a new set point
172
Long term regulation of BP is done mainly by
Blood volume
