The heart

  1. Lub
    bicuspid and tricuspid valves close
  2. Dub
    pulmonary and aortic semi-lunar valves close
  3. Cardiac conduction system
    contraction of the atria and ventricles occur automatically as a result of electrical impulses that originate in and are conducted by heart tissues.
  4. What four things happen as a result of the sinoatrial node?
    • 1. Depolarization spreads in the myocardium
    • 2. lft and rgt atria contract
    • 3. atria empty and ventricles fill
    • 4. impulse picked up by conduction fibers that stimulate #2
  5. Where is the Atrioventricular node found?
    on the floor of the rght atrim near septum
  6. Where is the atrioventricular bundle found and what does it split into?
    found in the upper part of the interventricular septum. Splits into the lft and right bundle fibers
  7. What is step four in the cardiac conduction system and where is it located?
    Right and left bundle fiber. Found in the septum
  8. What happens as a result of the Purkinje Fibers?
    the ventricular muscle fibers depolarize and the ventricles contract.
  9. How are the ventricular muscle fibers arranged as a result of the Purkinje Fibers?
    the ventricle muscles are arranged in whorls that "wring" the ventricles dry.
  10. In the Electrocardiogram what happens during the P Wave?
    atrial depolarization
  11. In the electrocardiogram, what happens during the QRS complex?
    ventricular depolarization and atrial repolarization
  12. In the Electrocardiogram, what happens during the T Wave?
    Ventricular repolarization
  13. What is special abou the QRS complex?
    The atrial repolarization is not seen because overshadowed by the QRS complex.
  14. Cardiac Cycle
    this is the sequence of events in the heart b/w the start of one contraction and the start of the next.
  15. Cardiac output
    the amount of blood pumped out by each ventricle in 1min.
  16. Cardiac Output Equation
    Cardiac Output=Stroke Volume*Heart Rate
  17. Stroke Volume
    the amount of blood pumped out by one ventricle w/ each beat.~70 ml/beat
  18. What five things is stroke volume regulated by?
    SA node, Autonomic Nervous System, temp, hormones, and ions
  19. SA node produces how many beats per min?
    75 beats per min
  20. Parasympathetic nervous sys
    inhibits heart rate
  21. sympathetic ner. sys.
    inc. heart rate
  22. Temperature
    with inc in temp there is an inc in heart rate
  23. The hormone epinephrine given off by the adrenal medulla will...
    stimulate inc. HR
  24. What is the name of the heart rate that will enhance the effects of the epinephrine and norepinephrine on the heart?
    Thyroxin(T4) from the thyroid gland
  25. K+
    because inc or dec K+ alters the polarized state.
  26. Hyperakalemia
    slows down HR
  27. hypoakalemia
    slows up HR
  28. Ca+
    needed for contraction of the cardiac muscle tissue
  29. Hypercalcemia
    speeds up HR
  30. hypocalcemia
    slows down HR
  31. Tachycardia
    fast beats over 100/min
  32. bradycardia
    slow beat <60/min
  33. Flutter
    chamber contracts regularly but very fast 250-350 beats/min
  34. Fibrillation
    rapid but uncoordinated contractions
  35. During fibrillation
    not all areas contract together
  36. During fibrillation, during atrial fibrillation
    one can survive
  37. During fibrillation, during ventricular fibrillation
    it can be fatal
  38. Arrhythmias
    due to conduction disorders. Any interference or block in cardia impulse conduction may be the cause.
  39. Pericardium
    the CT covering of the heart-made up of 2 layers
  40. Name four characteristics of visceral pericardium.
    • 1. inner most layer
    • 2. very thin, serous membrane
    • 3. puts out fluid
    • 4. forms the epicardium
  41. Parietal pericardium
    is the outermost layer
  42. Name four characteristics of the parietal pericardium.
    • 1. outermost layer
    • 2. thick
    • 3. forms the pericardial sac
    • 4. pericardial cavity
  43. pericardial cavity
    is the space b/w the 2 pericardial layers. It is fluid filled. For protection.
  44. The heart wall is composed of 3 layers
    • 1. Epicardium
    • 2. Myocardium
    • 3. Endocardium
  45. Epicardium
    outer layer, thin, serous
  46. Myocardium
    thickest, middle layer, cardiac muscle
  47. Endocardium
    serous, thin, innermost layer of the rise to the Purkinje Fibers that are specialized muscle fibers in the endocardium. Covers valves.
  48. Atria and auricles
    receive blood. Rt from body, left from lungs
  49. Ventricles
    pump bld out. Rt to lungs, left to body
  50. Atrioventricular sulcus (coronary sulcus)
    grooves b/w atria and ventricles, encircles the heart
  51. Interventricular sulci
    anterior and posterior, found b/w ventricles
  52. Systemic circuit (left side of the heart)
    left atrium->thru bicuspid valve-left ventricle-thru aortic semilunar valves-ascending aorta-aortic arch-descening aorta-arteries-arterioles-cap-venules-veins-superior or inferior vena cava-right atrium
  53. pulmonary circuit(right side of the heart)
    right atrium->thru tricuspid valve-right ventricle-thru pulmonary semilunar valves-pulmonary trunk-pulmonary arteries-pul.arterioles- pul. cap in lungs where gas exchange occurs-pul venules-pul. veins-left atrium
  54. Right coronary artery has two main branches
    posterior interventricular artery, marginal artery
  55. posterior interventricular artery
    feed the two ventricles
  56. marginal artery
    feeds the right atrium and right ventricles
  57. left coronary artery has 2 main branches
    circumflex artery, anterior interventricular artery
  58. circumflex artery
    feeds the left atrium and left ventricles
  59. anterior interventricular artery
    fees both ventricles
  60. The cardiac veins run parallel to the arteries. They empty into what?
    the coronary sinus that empties into the right atrium
  61. Three vessels contribute to the coronary sinus.
    • 1. Great Cardiac Vein
    • 2. Middle Cardiac Vein
    • 3. Small Cardiac Vein
  62. Great cardiac vein
    found in the anterior interventricular sulcus
  63. Middle cardiac vein
    found in the posterior interventricular sulcus
  64. small cardiac vein
    found in the inferior margin of the heart on the right
Card Set
The heart
About the lining of the heart, blood vessels of the heart, heart rate, and disorders of the heart.