Chapter 21
1. What carries blood under high pressure from the heart to tissue?
Arteries
2. ________ is the forces involved in circulating blood.
Hemodynamics
3. Arteries hold what type of volume?
Stressed volume
4. ________ are the last small branches off arterial tree.
Arterioles
5. Where is the site of highest resistance to blood flow?
Arterioles
6. Metarterioles emerge from _____ and supply a small group (10-100) of ______
which contribute to a capillary bed.
Arterioles; capillaries
7. What is the name of the vessel that is thin enough to allow exchange of nutrients;
blood; fluid; etc?
Capillary
8. What structure collects blood from capillary and merges with veins?
Venules
9. Veins bring blood _____ the heart.
Back to
10. Veins are a major what of blood?
Reservoir
11. What are the names of vessels of vessels that line the walls of large vessels?
Vasa vasorum
12. Name the 3 structures of arteries and veins.
Tunica intima- endothelium basement membrane
Tunica media- smooth muscle (external) elastic fibers
Tunica externa ( adventitia)- merges with connective tissue surrounding blood
vessel
13. What is the largest layer in the artery?
Tunica media
14. What type of artery is the aorta?
Elastic (conducting artery)- has smaller amount of smooth muscle and greater amount
of elastic tissue
15. What vessels play a key role in regulating blood flow by regulating resistance?
Arterioles
16. The vascular smooth muscle is innervated by what part of the autonomic system?
Sympathetic
17. True/False. A small change in the diameter of your arteries due to plaque build up
or loss of elasticity has a small or little effect on the flow.
False – it has a huge impact; causes 90% blockage
18. What term means intermittent contraction and relaxation of sphincter that allow
filling of capillary beds?
Vasomotion
19. What is the function of capillaries?
Exchange of nutrients and waste between blood and tissue fluid
20. What is the structure of a capillary?
Single layer of simple squamous epithelium and its basement membrane
21. Name the 3 types of capillaries and describe.
Continuous – no fenestrae; pores
Fenestrated – have pores
Sinusoidal- large diameter with large fenestrae; pores
22. Which types of capillaries have the fastest diffusion? Slowest diffusion?
Sinusoids; continuous
23. True/False. Veins have valves.
True
24. Veins hold what type of “volume”?
Unstressed
25. Tell the differences between arteries and veins.
Arteries- thicker walls; circular; under pressure; no valves; more elastic; carries
blood from hear.
Veins. - thinner walls; less muscle; irregular shape; not under pressure; has valves; c
carries blood to the heart.
26. If the aorta becomes stiff due to ware and tear what effect will the stiffness have on
blood flow?
The blood will flow more in spurts and not in a constant cyclic manner.
27. What causes varicose veins?
Leaky venous valves
28. What controls blood flow to each tissue?
The tissue need
29. What controls the cardiac output?
Mainly by the sum of all local tissue flow
30. True/False. Arterial pressure is controlled independently of either local blood flow
or cardiac output.
True
31. What percentage of blood volume at rest is in the systemic veins and venules?
60%
32. What ways do capillaries move materials in and out?
Diffusion; transcytosis; filtration; reabsorption
33. If filtration exceeds reabsorption where is material moving?
Out of capillary
34. If reabsorption exceeds filtration where is material moving?
Into the capillary
35. What do you want the rate of filtration to rate of reabsorption to be in the
capillaries?
Equal to each other
36. What is promoted by hydrostatic pressure and interstitial flow osmotic pressure?
Filtration
37. What is promoted by blodd collid osmotic pressure and interstitial fluid hydrostatic
pressure?
Reabsorption
38. What is Starling’s law of capillaries?
The volume of fluid and solutes reabsorbed is almost as large as the volume filtered
39. Do you have net reabsorption or filtration on the arterial sid of the capillaries?
Filtration
40. Do you have net reabsorption or filtration on the venous side of the capillaries?
Reabsorption
41. Where does the excess fluid go that is not reabsorbed on the venous side of the
capillaries?
Lymphatic capillaries collect it
42. High blood pressure promotes what?
Filtration
43. Low blood pressure promotes what?
Reabsorption
44. Blood collid osmotic pressure (BCOP) should be higher of lower on the venous side
of the capillaries?
Higher
45. If I drink pure water I will promote filtration or reabsorption?
Filtration
46. If I eat salty foods I would promote filtration or reabsorption?
Reabsorption
47. If BHP= 30mmHg IFOP=2mmHg IFHP = 3mmHg and BCOP = 26mmHg on
arterial side of capillaries what is the net filtration?
NFP= (30 +2) – (26 + 3) = 3mmHg
48. Pressure exerted by blood on walls of a vessel is caused by _______.
Contraction of the ventricles
49. Pressure exerted by blood on wall of a vessel is highest where?
In aorta
50. Greatest drop in pressure occurs where?
In arterioles
51. Pulse pressure is difference between what?
Systolic and diastolic
52. If a patient has a normal BP (120/80) what is their pulse pressure?
40 (120 -80=40)
53. What is mean arterial blood pressure (MABP)?
Average pressure in arteries (not an arithmetic average)
54. What is the equation for MABP?
MABP=diastolic BP +1/3(systolic BP – diastolic BP)
55. Why is it 1/3(systolic BP – diastolic BP) in the MABP equation?
Because it is not an arithmetic average
56. Blood pressure is measured by listening for what?
Korotkoff sounds – produced by turbulent flow in arteries as pressure released from
BP cuff.
57. What are the two “pumps” are in the venous return?
Skeletal muscle and respiratory
58. Where do you take blood pressure at?
At level of heart at brachial artery
59. What is the first sound you hear when you take blood pressure? (systolic or
diastolic)
Systolic
60. What is the second sound you herar when you take blood pressure? (systolic or
diastolic)
Diastolic
61. What factors affect circulation?
Pressure differences that drive the blood flow; resistance to flow; and venous return
62. What is the velocity of blood flow equation?
V=Q/A
63. Where is the greatest cross-sectional area?
In capillaries
64. As diameter of vessels decreases the total cross-sectional area ______ and velocity
of blood flow ____.
Increases; decreases
65. Speed of blood flow in cm/sec is _____ related to cross-sectional area.
Inversely
66. Blood flow is slower in arterial or venous branches?
Arterial
67. Blood flow becomes faster when vessels merge to form ______.
Veins
68. Circulation time is what?
Time it takes a drop of blood to travel from the right atrium back to the right atrium.
69. As vessel diameter increases the velocity of fluid flow through the vessel _____.
Decreases
70. Magnitude of Q in Q=∆P/R equation is _____ proportional to ∆P.
Directly
71. Magnitude of Q in Q=∆P/R equation is _____ proportional to R (resistance).
Inversely
72. What are the 2 resistance arrangements?
In series and in parallel
73. If you add resistance in parallel a(n) _____ happens to resistance. In series?
Decrease; increase in resistance
74. What are the advantages of having vessels in parallel?
Total resistance is less than any of the individual resistance; no loss of pressure; if
another resistance total decreases; if increase resistance total increases.
75. What does Poiseulle’s law state?
The flow of (Newtonian) fluid through rigid tubes is governed by pressure gradient
and resistance to flow.
76. What are the 3 properties that affect fluid and tube resistance in Poiseuille’s law?
Length of tube (l); radius of tube (r); viscosity of fluid (ŋ)
77. What is the Poiseuille’s law equation?
R=8 ŋl/(π r4)
78. Does a smaller vessel offer more/ less resistance to blood flow.
More
79. An increase in viscosity _____ resistance.
Increases
80. The longer the vessel the ______ the resistance to flow.
Greater
81. Resistance is regulated by what?
The radius of the vessel
82. Very small changes in the radius will have ______ affects on the resistance.
Huge
83. Name some cases where blood viscosity can change?
Dehydration; change in hematocrit; and changes in plasma protein concentration.
84. The greater the _____ the slower the flow.
Length
85. The greater the _____ the greater the flow.
Radius
86. Obesity would lead to hypo/hypertension.
Hypertension
87. What are laminar and turbulent flow?
Laminar- streamlined; outermost layer moving slowest and center moving faster.
Turbulent- interrupted; rate of flow exceeds critical velocity; fluid passes a constricton
sharp turn rough surfaces.
88. In normal conditions turbulent flow is found only where?
In aorta
89. What is critical velocity?
Laminar flow velocity increases with increase in pressure but up to a point
90. What type of flow is observed above critical velocity?
Turbulent
91. Reynolds number is used to predict what?
Whether blood flow will be laminar or turbulent
92. The viscosity of blood decreases with _____ in flow rate.
Increase
93. RBC tend to collect in center of lumen thus _____ the effective viscosity.
Reducing
94. Axial streaming reduces blood viscosity at ____ thus ____ resistance.
Edge; decreasing
95. What effect does decreased resistance have on flow?
It increases it
96. A high hematocrit as in plycytemia increases blood viscosity which _____ blood
flow through capillaries.
Slow
97. What is shear thinning?
The apparent viscosity diminishes as the blood flow rate increases (and vice versa)
98. The higher the compliance of a vessel the _____ volume it can hold at a given
pressure.
More
99. Aging decreases/ increases compliance of vessels.
Decreases
100. What do changes in compliance cause?
Redistribution of blood between arteries and veins
101. What is the equation for compliance?
C=V/P
102. What type of pump has steady pressure steady flow and no need for compliance?
Constant flow pump
103. What has the highest compliance? Middle? Lowest?
Veins; arteries; aging arteries
104. Cyclical pump and non-compliance vessels have what type of pressure and flow?
Intermittent
105. Cyclical pump and compliant vessels have what type of pressure and flow?
Steady
106. Laplace’s law states what?
It relates pressure; radius of vessel and tension on vessel wall
107. The importance of Laplace’s law is in what vessels?
Capillaries and alveoli
108. What is the term that means input during physical activity?
Proprioceptors
109. This term means changes in pressure within blood vessel?
Baroreceptors
110. What receptors monitor concentration of chemicals in the blood?
Chemoreceptors
111. What type of fibers does the vagus nerve have and what effect does it have on the
heart? Parasympathetic; decreases heart rate
112. Name the 2 type of baroreflexes of blood pressure.
Carotid sinus reflex and aorta reflex
113. What cranial nerve is involved in the carotid sinus reflex? the aorta reflex?
Glossopharyngeal (CN IX) vagus (CN X)
114. What is orthostatic hypotension?
Decrease in BP upon standing. Blood is pulled down to the lower extremities.
115. Locally systemic vessels _______ in response to low levels of oxygen. Pulmonary
vessels ________ in response to low oxygen.
Dilate; constrict
116. The aortic valve is _________ in this chart. Compliance is _________ in the
chart.
Narrowing; decreasing.
117. What effect does epinephrine and norepinephrine have on heart rate and force of
contraction?
Increases heart rate and increases the force of contraction
118. Which is the only hormone that decreases BP?
ANP (atrial natriuretic peptide)
119. Renin-angotensin-aldosterone mechanism occurs do to what?
A decrease in blood pressure
120. Renin activates what in the liver? Into what?
Angiotensinogen; angiotensin I
121. Aldosterone promotes what?
Reabsorption of Na
122. What effect does aldosterone have on the kidneys if there is low blood pressure?
Increases water reabsorption and decreases urine volume.
123. What effect does increasing water reabsorption and decreasing urine volume in the
kidneys have on blood pressure?
Increases blood pressure
124. What type of shock is due to loss of blood or body fluids?
Hypovolemic
125. What type of shock is caused by damage to pumping action of the heart?
Cardiogenic
126. What type of shock causes a drop in BP?
Vascular
127. What do osmoreceptors detect?
Increased osmotic pressure in blood vessels
128. What term means the failure of the cardiovascular system to deliver enough
oxygen and nutrients?
Shock
129. What type of shock could be due to hemorrhage sweating or diarrhea?
Hypovolemic
130. Cardiogenic shock could be caused by what?
MI, ischemia, valve problems or arrhythmias
131. What type of injury or trauma would cause vascular shock?
Head trauma
132. ______ shock is caused by blockage of circulation (pulmonary embolism)
obstructive
133. circulation is left side heart to body & back to heart
Systemic
134. _______ circulation is capillaries of GI tract to capillaries in liver
Hepatic portal
135. circulation is right-side heart to lungs & back to heart?
Pulmonary
136. The hepatic portal system is a subdivision off of what circulation system?
Systemic circulation
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