Volume 3 Chapter 2 Part 1

  1. Endocardium
    Innermost layer of the heart. Lines the chambers.
  2. Myocardium
    Heart muscle
  3. Pericardium
    • Protective sac surrounding the heart
    • Consists of the epicardium (touches the heart) and
    • Parietal pericardium (outer layer)
    • Containts 25 mL fluid between them
  4. Atrioventricular Valves
    • Control blood flow between atria and ventricles
    • Right: tricuspid
    • Left: mitral
  5. Semilunar Valves
    • Regulate blood flow from ventricles and the arteries
    • Aortic: left ventricle to aorta
    • Pulmonic: right ventricle to pulmonary artery
  6. Anastomosis
    Communication between two or more vessels
  7. Cardiac Cycle
    The period of time from the end of one cardiac contraction to the end of the next
  8. Diastole
    The period of time when the myocardium is realxed and cardiac filling and coronary perfusion occur
  9. Systole
    The period of the cardiac cycle when the myocardium is contracting
  10. Ejection Fraction
    Ratio of blood pumped from the ventricle to the amount remaining at the end of diastole
  11. Stroke Volume
    The amount of blood ejected by the heart in on cardiac contraction
  12. Preload
    The pressure within the ventricles at the end of diastole; commonly called the end-diastolic volume
  13. Starling's Law of the Heart
    Law of physiology stating that the more the myocardum is stretched, up to a certain amount, the more forcefull susbsequent contraction will be
  14. Afterload
    The resistance against which the heart must pump
  15. Factors Effecting Strok Volume
    • Preload
    • Cardiac contractility
    • Afterload
  16. Cardiac Output
    The amount of blood pumped by the heart in one minute
  17. Chronotropy
    Pertaining to heart rate
  18. Inotropy
    Pertaining to cardiac contractile force
  19. Dromotropy
    Pertaining to the speed of impulse transmission
  20. Intercalated Discs
    Specialized bands of tissue inserted between myocardial cells the increase rate in which the action potential is spread from cell to cell.
  21. Syncytium
    Group of cardiac muscle cells that physiologically function as a unit
  22. Cardiac Depolarization
    A reversal of charges at a cell membrane so the the inside of the cell becomes positive relative to the outside; the opposite of the cell's resting state in theich the inside is negative in relation to the outside
  23. Resting Potential
    The normal electrical state of cardiac cells
  24. Action Potential
    The stimulation of myocardial cells, as evidenced by a charge in the membrane electrical charge, that subsequently spreads across the myocardium
  25. Repolarization
    Return of a muscle cell to its preexcitation resting state
  26. Excitability
    Ability of the cells to respond to an electrical stimulus
  27. Conductivity
    Ability of the cells to propagate the electrical impulse from one cell to another
  28. Automaticity
    Pacemaker cells' capability of self-depolarization
  29. Contractility
    Ability of muscle cells to contract or shorten
  30. ECG Leads
    • Bipolar (limb)
    • Augmented (unipolar)
    • Precordial
  31. Bipoar Limb Leads
    EKG leads applied to the arms and legs that contain two electrodes of opposite (positive and negative) polarity (leads I, II, III)
  32. Einthoven's Triangle
    The triangle around the heart formed by the bipolar limb leads
  33. Augmented Limb Leads (Unipolar)
    EKG leads applied to the arms and legs, consisting of one positive electrode and a nonpolarized reference point that is created by the EKG machine combing two additional electrodes (aVR, aVL, aVF)
  34. Precordial (chest) Leads
    EKG leads applied to the chest in a pattern that permits a view of the horizontal plane of the heart (V1, V2, V3, V4, V5, V6)
  35. EKG Components
    • P wave
    • QRS complex
    • T wave
    • U wave
  36. EKG Time Intervals
    • PR Interval: 0.12-0.20 seconds (3-5 small boxes)
    • QRS Segment: 0.08-0.12 seconds (2-3 small boxes)
    • QT Interval: 0.33-0.42 seconds
  37. QT Interval
    Period from the beginning of the QRS to the end of the T wave
Card Set
Volume 3 Chapter 2 Part 1
Volume 3 Chapter 2 Part 1