《生理学》CHAPTER 4 CIRCULATI-7.ppt

文档介绍：CHAPTER 4 CIRCULATION
Professor Pan Jing-yun
Department of Physiology
SECTION 1  ELECTRICAL ACTIVITY OF HEART
I. BIOELECTRICAL  PHENOMENA OF  MYOCARDIAL CELL
Differences of AP configurations in different regions of the heart.
Fast response potential
Fast response cells: atrium cell and ventricle cells – working myocardium.
Fast response automatic cells: Purkinje fiber and bundle of His.
Slow response potential
Slow response cells: S–A node and A–V node.
Basic concepts
Depolarization –– cations influx ---- Na+,
Ca+ inward current
Repolarization –– cations efflux ---- K+
outward current
Hyperpolarization: Vm → more negative
than current:
inward < outward repolarization
inward > outward depolarization
inward = outward no change in Vm
TRANSMEMBRANE POTENTIAL OF MYOCARDIAL CELL AND THEIR IONIC BASIS