심장흥분전도계

소개글

심장흥분전도계

목차

Conductive System of Heart
(1) Sinus Node

Ionic Basis of SA Node Action Potential

Important factors that influence automaticity

Variables that Affect Automaticity of Pacemaker Cells

본문내용

(1) Sinus Node

  a. location
- superior lateral wall of RA immediately below
& lateral to superior vena cava opening
b. --- self excitation or pacemaker --

** Mechanism of self excitation **
    a. pacemaker potentials– “gradual depolarization”
- progressive reduction in K+ permeability
- inherent leakiness of sinus nodal fibers to Na+(Leak Na+ Channels, F(funny)-type)
- T-type Ca++channels - boost depolarizion
b. negativity of only 55 to 60 mV in RMP -
    c. action potential
- opening of L-type Ca++channels
    d. hyperpolarization by K+channel
– prevention of prolonged depolarization

참고 자료

없음