1. cardiac muscle vs. Skeletal?
    • cardiac- smaller in size, single-centered nucleus,
    • skeletal-do not branch between cells, do not have intercalated discs.
  2. when is first heart sound heard?
    AV valve closes
  3. when blood comes back to heart after going to lungs what structure does it go to first?
    left atrium
  4. what happens during isovolumetric phase of ventricule systole?
    Atrioventricular valve and semilunar valve closed
  5. auricle
    expandable extension of atrium
  6. what happens if damage to chordae tendinae?
    • 1- mitral regurgitation
    • 2- mitral valve prolapse
    • 3- bicuspid regurgitaton
    • 4- bicuspid prolapse
  7. when semilunar valve close what happens to AV valve?
  8. coronary sulcus location?
    marks border between atria and ventricle
  9. what happens during cardiac cycle?
    QRS complex of ECG precede the increase in ventricular pressure
  10. what structure deliver blood to myocardium?
    right and left coronary artery
  11. location of pecinate muscle
    muscle ridges run along surface of auricles
  12. first vessel to branch from aorta?
    coronary arteries
  13. stroke volume
    volume of blood ejected from each ventricle during contraction
  14. blood supplied to L atrium via?
    L coronary artery
  15. chordae tendineae do what?
    attach papillary muscle to cusps of atrioventricular valve
  16. first sign of coronary artery disease?
  17. what branches are part of R coronary artery?
    • marginal branch
    • posterior interventricular branch
  18. what increase cardiac output?
    • incrase venous return
    • incrase sympathetic stimulation
    • increase heart rate
  19. how long heart beat last?
    370 msec
  20. what do contractions of papillary muscle do?
    prevent AV valve from reverse into atria
  21. size of cells in conducting sytem and contain how many myofibrils?
    most of cells in conducting system are smaller then contractile cells of myocardium and contain few myofibrils
  22. branches of L coronary artery?
    • circumflex branch
    • anterior descending artery
  23. What is SA node known as?
    cardiac pacemaker /natural pacemaker
  24. Starlings law of heart re: cardiac output?
    directly related to venous return
  25. another name for visceral pericardium?
  26. if action potential initated in AV node how many heart beats per minute?
  27. where do great and middle cardiac veins drain?
    into coronary sinus
  28. what increase heart rate?
    • -sympathetic stimulation of nodal fibers
    • -incrase levels of epinephrin in flud around heart
    • -increase permeability of myhocardial membrane to sodium
    • -activation of cAMP in heart muscle
  29. function of pericardium?
    anchor heart to surrounding structures
  30. P wave
    depolarization of atria
  31. what structure permit blood flow from R to L atrium while lungs develop before birth?
    foramen ovale
  32. what happens when increased blood to R atrium?
    • cause SA node to depolarize faster
    • increase HR
    • trigger atrial reflex (bainbridge)
  33. why cant tetanic muscle contract in normal cardiac muscle cell?
    refractory period lasts until muscle cell relaxes.
  34. what circuit does L ventricle pump blood?
  35. what makes amt of force that blood comes out of heart?
    • degree of stretching at end of ventricle diastole
    • contractile of ventricle
    • amt of pressure required to eject blood
  36. depolarization phase of action potential is result of what?
    incrase membrane permeability to sodium
  37. intercalated disk is what?
    two cardiac muscle cells connected by gap junction
  38. ventricle systole what happens?
    AV valves close
  39. plateu phase is due to what?
    calcium channel remain open longer then sodium channel
  40. how many times heart beat daily?
  41. wha happens to ventricle chamber when L ventricle contracts ?
  42. where do calcium ions come from for contraction?
    outside cell
  43. liters of blood pumped daily?
  44. what happens as result of long refractory period ?
    no tetany
  45. calcium channel blockers do what?
    decrease force of heart contracation
  46. enzymes found in blod following MI?
    • LDH
    • SGOT
    • MB-CK
    • CPK
  47. order of conduction system?
    • sa node
    • av node
    • av bundle
    • bundle branches
    • purkinje fibers
  48. coronary thrombosis
    clot form on plaque of coronary vessel and blocks blood flow
Card Set
How the heart works