SFOS 15

  1. Index of contractility
    • dP/dt during isovolumentric contraction
    • measure of contractility
  2. What provides most energy for cardiac function?
    Secondary sources?
    Oxidative metabolism of fatty acids

    secondary - lactate and glucose
  3. Volume work vs. Pressure work
    Volume work - greater stroke volume (less energy), seen during exercise

    Pressure work - greater developed tension (more energy), seen in hypertension
  4. Phases of volume-pressure diagram
    • I - filling of ventricle
    • II - isovolumetric contraction
    • III - ejection from ventricle
    • IV - isovolumetric relaxation
  5. Intrinsic cardiac regulation
    • Response to changes in venous return by inherent muscle properties
    • Frank-Starling mechanism: greater contraction with more optimal filling stretch
  6. Extrinsic cardiac regulation
    • Autonomic nervous system
    • Hormonal signaling
  7. Effects of sympathetic stimulation
    • Increase SA node rate
    • Increases rate of conduction
    • Increases force of contraction
  8. Effects of parasympathetic stimulation
    • Decreases SA node rate
    • Hyperpolarizes fibers between SA and AV nodes
    • Decreases force of contraction
  9. Intrinsic heart rate
    Heart rate prevailing during complete autonomic blockade
Author
zf2010
ID
80026
Card Set
SFOS 15
Description
SFOS 15
Updated