Card Set Information

2012-03-10 17:10:34

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  1. What three structures/layers do all blood vessels have?
    • tunica intima/interna
    • tunica media
    • tunica externa/adventitia
  2. What is the tunica media composed of?
    smooth muscle and elastic fiber layer
  3. What layer is the endothelium that lines the lumen of all vessels?
    tunica interna
  4. What is the lumen of blood vessels?
    central blood containing space
  5. What is the tunica media regulated by?
    sympathetic nervous system
  6. What layer of blood vessels does vasoconstriction occur?
    tunica media
  7. What 3 things happen in vasoconstriction?
    • smooth muscle contractions
    • reduction in lumen diameter
    • high BP
  8. What 3 things happen in vasodialation?
    • smooth muscle relaxes
    • increase in lumen diameter
    • low BP
  9. What layer of blood vessels is made of collagen fibers which protect and reinforce vessels?
    tunica externa
  10. What do larger blood vessels contain that nourishes the blood vessel wall?
    vasa vasorum
  11. Where do arteries, veins, and capillaries transport blood?
    • arteries - from the heart
    • veins - to the heart
    • capillaries - tissue cells
  12. What are the largest of arteries?
    elastic arteries
  13. What are the conducting vessels?
    elastic arteries
  14. What type of arteries are the thick walled and near the heart?
    elastic arteries
  15. What can elastic arteries withstand by smoothing out?
    large blood pressure fluctuations
  16. What are the next largest arteries next to elastic arteries?
    muscular arteries
  17. What type of arteries are the distributing vessels?
    muscular arteries
  18. What type of artery delivers blood to the body and organs?
    muscular arteries
  19. How does the tunica media differ in the muscular arteries?
    more smooth muscle and less elastic tissue
  20. What type of artery is active in vasoconstriction?
    muscular arteries
  21. How do arterioles control flow into capillary beds?
    vasconstriction and vasodialation
  22. What is the name for resistance vessels?
  23. What type of arteries lead into capillary beds?
  24. What are the smallest of blood vessels?
  25. What are three types of capillaries?
    • continuous capillaries
    • fenestrated capillaries
    • sinusoidal capillaries
  26. What blood vessels are composed of endothelium with sparse basal lamina?
  27. How many RBCs pass through capillaries at a time?
    1 RBC a time
  28. Which type of capillaries have an uninterrupted lining?
    continuous capillaries
  29. What type of capillaries are abudant in skin and muscle?
    continuous capillaries
  30. What structure allows the passage of fluid in the structure of capillaries?
    intracellular cleft
  31. What type of capillaries have an endothelium layer with fenestrations?
    fenestrated capillaries
  32. What do the pores of fenestrated capillaries allow?
    greater permeability to solutes and fluid
  33. Where are fenestrated capillaries found?
    small intestines, endocrine glands, kidneys
  34. What type of capillaries are leaky and fenestrated with large lumens?
    Sinusoidal capillaries
  35. Which type of capillaries form the blood brain barrier?
    continuous capillaries
  36. Why are sinusoidal capillaries so much more fenestrated?
    so large molecules such as protein and blood cells can pass through
  37. What type of capillaries are found in the liver, bone marrow, lymphoid tissue, and some endocrine organs?
    sinusoidal capillaries
  38. What open to allow blood to flow through true capillaries?
  39. When a person is at rest/ parasympathetic system is active, where is most of their blood volume and why?
    • abdomen
    • digestion and kidney function
  40. When a person's sympathetic nervous system is activated (when they're exercising), where is most of the blood flow?
    skeletal muscles
  41. Does blood from the brain fluxuate?
    No, stays at ~750mL
  42. What is formed when venules converge?
  43. Is pressure in veins low or high?
  44. What are the body's blood reservoirs?
  45. Which has thinner walls, arteries or veins?
  46. What forms when capillary beds unite?
  47. What does it mean that veins are reservoirs, or capacitance, for blood?
    There is greater than 55% of blood found in the veins, although still moving
  48. Why is more blood found in the veins?
    Lumen is wider, more blood can flow without increasing pressure
  49. What is actual volume of blood flowing through a vessel/organ/ or the entire circulation in a given period, and how is it measured?
    • blood flow
    • measured in ml per min
  50. What is the force, per unit area, exerted on blood vessel walls by the contained blood, and how is it measured?
    • blood pressure
    • mm Hg
  51. What does the difference in pressure provide?
    • the driving force which keeps blood moving
    • from high to low pressure
  52. What is the opposition to flow of blood, measured in the amount of friction blood encounters in vessels?
  53. What is resistance referred to as?
    peripheral resistance (PR)
  54. What 3 factors cause peripheral resistance?
    • blood viscosity
    • blood vessel length
    • blood vessel diameter
  55. What is the thickness of blood called, and what happens when there is an increased thickness?
    • blood viscosity
    • increased viscosity=increased BP (polycythemia)
  56. What happens when blood vessel length is longer?
    increased resistance, increased BP
  57. Do babies or adults have higher BP and why?
    adults have higher BP because they have greater blood vessel length
  58. Which 2 of the three factors of resistance are relatively constant?
    blood viscosity and blood vessel length
  59. What factor frequently changes and alters peripheral resistance?
    • blood vessel diameter
    • vasoconstriction and vasodiameter
  60. What contributes more to peripheral resistance, larger arteries or small diameter arterioles?
    • large arteries contribute little to PR
    • small diameter arterioles are the major determinate of peripheral resistance
  61. Resistance is the _______ factor in influencing local bloodpressure
    most important
  62. When resistance increases, what happens to blood pressure?
    blood pressure increases
  63. What is blood flowing through vessels along a pressure gradient?
    systemic blood pressure
  64. Where is systemic pressure highest?
    in the aorta
  65. Where does systemic pressure decline?
    as it travels trhough the length of the pathway
  66. Where is systemic pressure 0 mmHg?
    right atrium after receiving blood from vena cava
  67. What is arterial BP like?
    pulsatile, rising and falling
  68. What is pressure that exerted on arterial walls during ventricular contraction?
    systolic pressure
  69. What is the lowest levels of arterial pressure during a ventricular cycle?
  70. What is athe range of blood pressure for capillaries?
    20-40 mmHg
  71. What is the capillary blood pressure good enough for?
    • filtrate blood into interstitial space
    • distribute materials between blood and tissues
  72. What is venous BP when returning to the heart?
  73. Why does blood in the veins need help pumping blood to the heart?
    BP is too low
  74. What 2 variables act on diffusion of blood between capilarries and interstitial space?
    • hydrostatic pressure
    • osmotic pressure
  75. What 2 things does maintaining blood pressure require?
    • cooperation of the heart, blood vessels, and kidneys
    • supervision of the brain (medulla, hypothalymus/pituitary)
  76. What kind of control counteracts moment to moment fluctuations in BP by altering peripheral resistance?
    short term
  77. What is changing in short term control of BP?
    • blood vessel diameter
    • vasoconstriction, vasodialation
  78. What acts as a short term control of BP?
    • nervous system:
    • baroreceptors and vasomotor center (medulla)
    • chemicals:
    • epinephrine
    • ADH
    • Alcohol
    • Nicotine
  79. Where are basoreceptors found?
    aortic arch and cartoids
  80. What do baroreceptors do when they are stimulated?
    when stimulated(BP is high), basoreceptors inhibit the vasomotor center and decrease heartrate/contractility/cardiac output
  81. When are basoreceptors inhibited?
    When BP is low
  82. What do basoreceptors do when they are inhibited?
    when basoreceptors are inhibited (BP is low), the vasomotor system is stimulated to increase resistance/BP/contractility/ cardiac output
  83. What 3 chemicals increase BP?
    • epinephrine
    • ADH
    • nicotine
  84. What 2 chemicals decrease BP?
    • Alcohol
    • histamine
  85. What is the relation between histamine and epinephrine when associated with allergies?
    • basophils release histamine when stimulated by allergy
    • histamine acts on the whole body dialting vessels
    • BP decreases drastically
    • epinephrine shots are used to constrict vessels to counteract histamine reaction
  86. What 3 things helps increase venous BP to return blood to the heart?
    • respiratory pump
    • muscle pump
    • valves
  87. What do long term controls for regulating Bp involve?
    regulating blood volume
  88. What do the kidneys directly do if the body has increased BP?
    • kidneys are stimulated to let go of water
    • blood viscosiity decreased
    • BP decreased
  89. What do the kidneys directly do if the body has decreased BP?
    • kidneys are stimulated to conserve water
    • blood thickness is increased
    • BP increased
  90. What does the kidney release if BP declines?
  91. What is the potent vasoconstrictor the kidney controls the release of?
    angiotensin II
  92. What two chemicals does angiotensin stimulate the release of to increase BP?
    ADH and Aldosterone
  93. What 2 ways does the kidney act to maintain long term blood pressure?
    direct and indirect
  94. What process does the indirect renal mechanism for increasing BP involve?
    renin-angiotensin mechanism
  95. What 5 steps happens in the renin angiotensin mechanism for increasing BP?
    • kidneys release renin
    • renin binds to inactive angiotensinogen in the blood stream
    • renin converts angiotensinogen to angiotensin I
    • angiotensin I travels to capillaries in the lungs
    • enzyme in lungs converts angiotensin I to angiotensin II
  96. What enzyme converts angiotensin I to angiotensin II?
    angiotensin converting enzyme (ACE)
  97. What 3 things does angiotensin II do to increase BP?
    • constricts blood vessels
    • stimulates ADH release
    • stimulates adrenal cortex to release aldosterone
  98. What is the average BP?
  99. When is BP most often highest in a person's daily routine?
    in the morning
  100. What is the term for a person's BP being below 100 mm Hg?
  101. What is hypertension?
    When a person's BP is above 140/90 + mmHg
  102. What is the major cause of heart failure, vascular disease, renal failure and stroke?
  103. What 3 affects happen on the heart and blood vessels in a person with hypertension?
    • heart is forced to pump against greater resistance
    • heart is weakened
    • blood vessels are damaged
  104. How is hypertension treated?
    • betablockers
    • diuretics
    • ACE inhbitors
  105. What are the risk factors for hypertension?
    • diet/obesity
    • age
    • race
    • heredity
    • stress
    • smoking
    • exercise
  106. What is the cause of circulatory shock?
    • blood vessels inadequetly filled
    • blood cant circulate normally
    • tissues cant receive blood flow
  107. What are 3 kinds of circulatory shock?
    • hypovolemic
    • vascular
    • cardiogenic
  108. Which type of circulatory shock results from a large scale blood loss?
    hypovolumeic shock
  109. Which type of circulatory shock results from extreme vasodialation and decreased peripheral resistance?
    vascular shock
  110. What type of circulatory shock happens when an inefficient heart cannot sustain adequate circulation?
    cardiogenic shock
  111. What type of circulatory shock is associated with severe allergic reactions?
    vascular shock
  112. What happens to arteries during atherosclerosis?
    walls of arteries thicken
  113. Why do the walls of arteries thicken in a case of atheroclerosis?
    irritation to the endothelium
  114. What issues occur during atheroclerosis?
    • inflammation
    • plaque development
    • arteries become hardened and narrow
    • hypertension increases
  115. What is arteriosclerosis?
    end stage of atherosclerosis