CVR2

  1. What are the 4 properties of the heart?
    • autorythmicity
    • contractility
    • excitability
    • conductivity
  2. What are the parts of the electrical conducting system?
    • SA node
    • AV node
    • Purkinje's fibers
    • HIS bundle
    • Right and left bundle branches
  3. What 2 kinds of cells make up the heart?
    • Mechanical cells
    • Cells of electrical system
  4. The cells of electrical system are actually these
    Modified cardiac muscle cells
  5. What 2 things do interclated discs contain?
    • Desmosomes - attach cells together
    • Gap junctions - spread action potentials
  6. What is the resting membrane potential in cardiac cells?
    -80 to -90 mv
  7. This ion generates resting membrane potential
    K+
  8. What is the Nernst equation?
    61.5 log10 (Xo / Xi)
  9. These are 2 types of action potentials in the heart
    • Fast
    • Slow
  10. Which cells have fast response action potentials?
    • atrial cells
    • ventricular cells
    • His cells
    • Purkinje cells
  11. Which cells have slow action potentials?
    • AV node
    • SA node
  12. Fast AP:
    Image Upload 2
    • 0= Na influx
    • 1= Na close and open specific K+ channels
    • 2= open calcium channels
    • 3= close calcium open K+
    • 4= rest
  13. The refractory period spans this time
    depolarization half way down repolarization
  14. Pacemaker Potential:
    Image Upload 4
    • 1. K+ close, Naf open
    • 2. Naf close, T-calcium open
    • 3. T-calcium close, L-calcium open
    • 4. L-calcium close, K+ open
  15. The suppression of all other pacemakers by the SA node is called this
    overdrive suppression
  16. Conduction of AP
    Image Upload 6
    • 1. AP made in SA node
    • 2. Rapid spread through atria
    • 3. Delay
    • 4. Goes through His bundle
    • 5. Goes through ventricles
    • 6. Rest
  17. These cells have the largest diameter with most of gap junctions
    Purkinje cells
  18. These cells have small diameter and less gap junctions
    AV node cells
  19. Image Upload 8
    Intercalated Disc between cells
Author
Bobopudge
ID
64636
Card Set
CVR2
Description
Autorhytmicity and Conduction in the Heart
Updated