APK Exam3 Ch13 Cardio

Card Set Information

APK Exam3 Ch13 Cardio
2011-11-05 18:53:21
APK Exam3 Ch13 Cardiovascular System

APK Exam3 Ch13 Cardiovascular System
Show Answers:

  1. Cardiovascular system transports substances including: (3)
    • oxygen and nutrients to cells
    • wastes from cells to liver and kidneys
    • hormones, immune cells, and clotting proteins to specific target cells
  2. 2 valves of heart
    • Atrioventricular
    • Semilunar
  3. Which has thicker wall, left or right ventricle? Why?
    Left, b/c has to pump blood to body (right is thinner b/c blood is coming in)
  4. 3 layers of heart wall

    Briefly describe each layer
    • Endocardium: layer of endothelial cells
    • Myocardium: cardiac muscle
    • Epicardium: external membrane
  5. Which are larger, myocardium or skeletal muscle cells?
  6. Defining properties of myocardium cells (9)
    • Small cells
    • One nucleus
    • Striations (myofilaments)
    • Branching cells
    • Intercalated disks: gap junctions & desmosomes
    • Aerobic muscle
    • No cell division after infancy-growth by hypertrophy
    • 99% contractile cells
    • 1% autorhythmic cells
  7. What is the importance of gap junctions in myocardium cells?
    Cause heart to contract as a unit
  8. What is the importance of desmosomes of myocardium cells?
    Resist stress
  9. Is the cardiovascular system an open or closed system?
  10. Heart capillaries are supplied by coronary arteries that arise from ____. These are specifically for the heart & provide heart w/nutrients.
  11. One of the main reasons for heart attack
    Blockages in coronary arteries
  12. Wave of contraction through the myocardium
  13. Which contracts first, atria or ventricles?
  14. What are the 2 atrioventricular valves?
    • Tricuspid valve (right valve) (made of 3 tissues)
    • Bicuspid valve (left valve) = mitral valve (made of 2 tissues)
  15. What are the 2 semilunar valves?
    • Aortic valve
    • Pulmonary valve
  16. What are the locations of semilunar valves?
    • Aortic valve: b/w left ventricle & aorta
    • Pulmonary valve: b/w right ventricle & pulmonary artery
  17. Series of events in the heart that pump blood
    Cardiac cycle
  18. What the two main periods of the cardiac cycle?
    • Systole = ventricle contraction
    • Diastole = ventricle relaxation
  19. Blood flows from ___ pressure to ___ pressure. So the blood in ___ chambers flow to the ___ chambers and the blood flows from ventricles to the ___ or the ____.
    • high, low
    • atria, ventricles
    • ventricles, pulmonary artery or aorta
  20. What causes AV and semilunar valves of heart to open?
    • Pressure gradients:
    • AV valves: pressure atria > pressure ventricles
    • Semilunar valves: pressure ventricles > pressure arteries
  21. 4 phases of cardiac cycle
    • 1.) Ventricular filling
    • 2.) Isovolumetric ventricular contraction
    • 3.) Ventricular ejection
    • 4.) Isovolumetric ventricular relaxation
  22. 2 phases of ventricular filling & what happens
    • passive phase: no atria or ventricular contraction
    • active phase: atria contract
  23. 1st phase cardiac cycle: Ventricle filling
    Pressure atria ____ pressure ventricles
    AV valves ___
    Passive phase:
    Active phase:
    • >
    • open
    • no atria or vent contraction
    • atria contract
  24. 2nd phase cardiac cycle: Isovulumetric ventricular contraction
    AV and semilunar valves ___
    Ventricular pressure ___
    • closed
    • increases
  25. 3rd phase cardiac cycle: Ventricular ejection
    Semilunar valves ___
  26. 4th phase cardiac cycle: Isovolumetric ventricular relaxation
    Ventricular pressure ___
    AV and semilunar valves ____
    • decreases
    • closed
  27. Maximum aortic pressure in cardiac cycle
    systolic pressure
  28. minimum aortic pressure in cardiac cycle
    Diastolic pressure
  29. Mean arterial pressure (MAP) =
    DP + [(SP-DP)/3]

    (1/3 b/c we spend 1/3 of our time in systole)
  30. Volume of blood in ventricle at the end of diastole
    End-diastolic volume (EDV)
  31. Volume of blood in ventricle at the end of systole
    End-systolic volume (ESV)
  32. Which phases of cardiac cycle is there no chg in amt of blood in ventricles b/c valves are closed?
    2 &4
  33. Volume of blood ejected by the ventricle each beat
    Stroke volume
  34. SV =
    EDV - ESV
  35. Fraction of end-diastolic volume ejected during a heartbeat
    Ejection fraction
  36. Ejection fraction =
  37. What causes the sound of the heart?
    Turbulent flow when valves close
  38. Describe first heart sound & what happens
    • Soft lubb
    • AV valves close simultaneously
  39. Describe second heart sound & what happens
    • Louder dubb
    • Semilunar valves close simultaneously

    (louder b/c more pressure)
  40. Ability to generate one's own rhythm
  41. Heart has conduction system containing autorhythmic cells which help spread excitation through the heart. How can the heart cells do this and what are they called?
    • They produce their own action potential spontaneously by depolarizing.
    • Pacemaker cells
  42. Rapidly conduct action potentials initiated by pacemaker cells to myocardium
    Conduction fibers
  43. Commonly called the pacemaker of the heart b/c it sets heart rate
    Sinoatrial node
  44. Where are pacemaker cells located?
    Sinoatrial & atrioventricular nodes
  45. Internodal pathways, Bundle of His, and Purkinje fibers are all ___ of the ___
    conduction fibers of the myocardium
  46. Junctions b/w adjacent myocardial cells
    Intercalated disks
  47. ___ are for electrical coupling & spread of excitation b/w cells
    Gap junctions
  48. These stretch to prevent heart celsl from damage when contracting
  49. Describe the beginning of spread of excitation in heart
    • SA node to AV node
    • SA node to right atrium to left atrium (rapid)

    (both happen at same time)
  50. From the AV node, excitation is spread:
    from atria to ventricles (slow which allows atria to contract before ventricles)
  51. Describe excitation of ventricles
    Down bundle of His then up Purkinje fibers which contact ventricle contractile cells, causing ventricle to contract from apex up
  52. In heart, like muscle cells, depolarizations lead to more action potentials and hyperpolarizations lead to fewer action potentials.
  53. Calcium is removed from cytosol, causing troponin and tropomyosin return to position covering myosin binding sites on actin during ____
    relaxation of cardiac muscle

    • (Calcium release and calcium re-uptake have the
    • same roles as they do in skeletal muscle)
  54. external measure of electrical activity of the heart which can be recorded from electrodes on the skin
    electrocardiogram (ECG)
  55. Pace generated by SA node
    Sinus rhythm
  56. Abnormal ECG rhythms:
    • Fast sinus rhythm
    • Slow sinus rhythm
  57. Loss of coordination of electrical activity of heart, causing rapid death unless corrected
    Ventricular fibrillation
  58. Volume of blood pumped by each ventricle per minute
    Cardiac Output
  59. Cardiac output =
    Stroke volume x Heart rate
  60. Average resting cardiac output = ___ L/min
  61. Average blood volume = __ L
    5.5 L
  62. 2 ways in which cardiac output is regulated
    • Intrinsic: autoregulation
    • Extrinsic: neural & hormonal
  63. What determines heart rate?
    SA node firing rate
  64. What would the heart rate be if we had no
    extrinsic control? ie What is the SA node intrinsic firing rate?
    100 beats/min
  65. HR when parasympathetic system dominates
    75 beats/min
  66. What does sympathetic activity do to SA node
    Activates receptors in SA node, causing an increase in open sodium and Ca channels, causing an increase in rate of spontaneous depolarization, causing increase in HR
  67. What does parasympathetic activity do to SA node
    cells? (vagus nerve)
    Activates receptors in SA node, causing opening of K+ channels and closing of Ca channels, causing decrease in rate of spontaneous depolarizations and hyperpolarizing the cell, causing decrease in HR
  68. What does the autonomic nervous system (both symp & parasymp) do to the AV node?
    • Sympathetic: increase conductoin velocity through node
    • Parasympathetic: decrease conduction velocity through node
  69. How to hormones affect heart rate?
    • Epinephrine: same effect as symp nervous system
    • Glucagon: increases HR
  70. What extrinsic factors affect stroke volume? In general, what does sympathetic activity do to heart muscle conctractility?
    • Hormones (thyroid hormones, insulin, glucagon increase force of contraction) & sympathetic nervous system
    • Increases cardiac contractility
  71. Specifically, what does sympathetic activity do to heart muscle conctractility?
    Increases sympathetic activity so increases epinephrine release, strength & rate of contraction, and rate of relaxation
  72. Pressure in aorta during ejection
  73. What intrinsic factors affect stroke volume?
    afterload, end diastolic volume
  74. How does a higher afterload during intrinsic control affect stroke volume?
    Decreases SV
  75. What is preload?
    End-diastolic pressure
  76. What causes an increased EDV? (3)
    • filling time
    • atrial pressure
    • central venous pressure
  77. What is the Frank-Starling law?
    An increased EDV stretches muscle fibers, so fibers are closer to optimum length, resulting in stronger contraction, which increases SV

    (ie An increase in EDV causes SV to increase)