151.L1.Lect5_6.Cardiovasc.11.18_20.13.Stu (1)

Voltage gated ca ion 2 channels open around 50 mv 50 3

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Unformatted text preview: 20mV) -90mV 2. Voltage gated Ca++ ion 2. channels open around -50 mV -50 3. Ca++ influx into the 3. myocardial cell induces it to contract contract 4. Ca++ influx rapidly 4. streams to the next myocardial cell, opening its Ca++ channels and causing it to contract, and so on… to http://en.wikipedia.org/wiki/File:ECG_Principle_fast.gif Fetal mouse heart beating, time sequence of Ca++ influx Campbell - calcium “wave” originates (top right of Figure 42.10 heart, yellow/orange) in SA node and spreads over atrium (top chamber, only one atrium at this age) - equivalent of AV node slows Ca++ “wave” progression to ventricle (only one at this age) Kotlikoff et al., PNAS, 2006. iPS “Beating” of human induced pluripotent stem Beating” differentiated into myocardial cells differentiated cells Campbell Figure 42.10 URL for SA node dynamic function: http://en.wikipedia.org/wiki/Ventricular_escape_beat Opposing Systems Regulate Heart Rate at...
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