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2011-04-05 09:11:08
Human Physio

Chp 23-25
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  1. cardiovascular system composed of
    • blood
    • heart
    • vessels
    • lungs
  2. subdivisions of cardiovascular system (3)
    • systemic circulation
    • pulmonary circulation
    • lymphatic circulation
  3. components of conduction pathway
    • sinoatrial node (SA)
    • atrioventricular node (AV)
    • bundle of his
    • bundle branches
    • purkinjie fibers
  4. fast response action potentials (3)
    • cardiac muscle
    • purkinje fibers
    • bundle branches
  5. slow response action potentials (2)
    • SA node
    • AV node
  6. slow action potentials are associated with
  7. T/F slow action potentials never rest
  8. SA node is affected, the sympathetic nerve activites are
    increased rate of diastolic depolarization
  9. when the AV node is affected, the sympathetic nerve activites are
    increased conduction rate
  10. when the artial muscle is affected, what is the sympathetic nerve activites
    increased strength of contraction
  11. an increase in HR under sympathetic activity causes a release of
  12. an increase in HR under parasympathetic activity causes a release of
  13. when ACH binds to its receptors what 2 things happen?
    increases K+ permeability and decreases Ca+ permeability
  14. what is the oxygen level of the cardiac muscle?
    aerobic capacity
  15. cardiac muscle is innervated by
    neurons of the autonomic branch of the peripheral nervous system
  16. T/F cardiac muscle has muscle fibers in a chamber to essentially contract in unison
  17. electrical synapses
    communication site between cells or with different regions within a cell
  18. how is the electrical synapses message carried?
  19. T/F electrical synapses have neurotransmitters
  20. intercalated disks
    electrical synapses in the heart
  21. what 2 ways do intercalated disks enhance conductivity?
    • allows action potentials to spread from:
    • - one cardiac muscle fiber to an adjacent one
    • - within a cardiac fiber
  22. where do all myofibers contract in unison?
    atria or ventricles
  23. what is the contraction of cardiac muscle dependent on?
    extra-cellular Ca+
  24. how does the extra-cellular Ca+ enter the cell? (2)
    • via voltage regulated channels on the plasma membrane
    • T-tubule
  25. by having the extra-cellular Ca+ in the cardiac muscle fiber, what does it extend?
    • duration of action potential- ensures enough time for emptying the artia/ventricles
    • absolute refractory period- cardiac muscle needs to fully relax before it can contract
  26. which valve is from the atria to ventricles?
    AV valve
  27. which valve is from the right ventricle to the pulmonary artery?
    pulmonary valve
  28. which valve is from the left ventricle to the aorta?
    aortic valve
  29. when blood flows from the right atrium to the right ventricle, which valve needs to open?
    right AV valve
  30. when blood goes from the right ventricle to the pulmonary artery, which valve has to open?
    pulmonary valve
  31. when blood goes from the left atrium to the left ventricle, which valve has to open?
    left AV valve
  32. systole
    contraction of the heart
  33. diastole
    relaxation of the heart
  34. temporal pattern
    when atria are in systole, ventricles are in diastole
  35. what is phase 1 of the cardiac cycle called?
    isovolumetric ventricular contraction
  36. what is phase 2 of the cardiac cycle called?
    ventricular ejection which the aortic and pulmonary vavles are opened
  37. what is phase 3 and 4 of the cardiac cycle called?
    isovolumetric ventricular relaxation
  38. what is phase 5 and 6 of the cardiac cycle called?
    atrial contraction in which the AV valve is opened
  39. in what phase is the ventricular volume isnt changing?
  40. in what phase is the having rapid ejection?
  41. in what phase is the blood volume the same?
    3 and 4
  42. in what phase the heart filling actively?
  43. in what phase can the heart have passive or active filling?
  44. cardiac output
    the volume of blood ejected from the ventricles per minute
  45. what is the resting CO?
    5 L
  46. what is the max CO?
    20-40 L/min
  47. equation of SV
    • EDV - ESV
    • starting volume - final volume
  48. ejection fraction
    fraction of blood ejected from the ventricles during ventricular stage
  49. equation for ejection fraction
    (SV/EDV) 100
  50. 3 things EDV can be influenced by
    • time of ventricular diastole
    • blood volume
    • venus pressure
  51. venous return
    volume of blood the returns to the right atrium
  52. ventricular filling is influenced by
    heart rate
  53. time of ventricular diastole is
    ventricular filling
  54. what is circulating blood volume proportional to (2)
    • urine volume
    • tissue fluid volume
  55. what is venous pressure around?
  56. veins have greater _____ compared to arteries? (2)
    • distensibilty
    • compliance
  57. diameter of blood vessels is influenced by (2)
    • ANS
    • skeletal and respiratory muscle contraction
  58. dense bodies are connected by
    intermediate filaments
  59. what does calcium bind to for smooth muscle contraction?
  60. for smooth muscle contraction, the increase in sympathetic activity causes what? (2)
    • increase in frequency and strength of contraction
    • reduces the diameter of vessel
  61. when VP is increases, what else is also?
    right atrial pressure
  62. when venous pressure is equal to right atrail pressure, what happens to venous return?
    there is no VR
  63. frank starling law
    the volume of blood that enters the ventricles is proportional to the volume of blood that is ejected from the ventricles
  64. increase in blood does what to sarcomeres?
    increases the length
  65. an increase in sympathetic activity does what to ESV?
    decreases it
  66. when MAP increases, what happens to the ESV?
    increases which then decreases SV
  67. what is normal range for MAP?
    90-100 mmHg
  68. an increase of sympthetic activity does what for smooth muscle contractions? (everything)
    • increases: HR, EDV, CO, VP, VR, SV
    • decreases: time of diastole, ESV, diameter of veins
  69. at rest, where is most of the blood distributed?
    GI tract and renal
  70. left atrium and ventricle compose what artery?
    left coronary artery
  71. when is there no blood flow to the heart?
  72. what does the meta-arterioles connect?
    arterioles to venules
  73. what does the meta-arterioles do?
    opens new "capillaries" during relaxation
  74. an increase in metabolic activity increases blood flow how?
  75. when the precapillary sphincters are sensed with oxygen during an increase of metabolic activity, what happens?
    they contracted which decreases blood flow
  76. an increase of CO2 does what to capillaries?
    vasodilation which allows more blood flow
  77. why does blood pressure oscillate in arteries?
    • in systole, the aortic valve opens letting blood in which expands in pressure and volume
    • in diastole, the blood leaves and then there is an elastic recoil
  78. why does blood pressure drop as blood travels from the arteries to veins?
    capillaries are between them which have more surface area and veins are more compliant
  79. equation of MAP
    (CO)(total peripheral resistance)
  80. laminar flow
    resistance to friction forces as blood travels over the walls of vessels
  81. an increase in radius does what to PRT?
    decreases it
  82. what is MAP regulated by?
    • short-term: nervous system
    • long-term: endocrine and renal
  83. what 2 things regulate short-term regulation of MAP?
    • baroreceptors
    • medulla
  84. where are the baroreceptors found?
    • cartoid sinuses
    • aortic arch
  85. where does the medulla send signals to?
    • cardiac control center: regulates HR
    • vasomotor center: regulates PRT