BION 3202

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BION 3202

• Lecture 2. Contraction of Heart Tissue

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Sodium Channel Gating
Extracellular
Intracellular
Activation gate
Inactivation gate
Closed
INa
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Ionic Current
IK1
Cell membrane
INa
IL,Ca
IKr
IKS
RyR
SR ATPase
Sarcoplasmic Reticulum
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Ionic Currents A few more
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How does current go from one cell to the next?
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Figure 14-10b
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(No Transcript)
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In myocardium, voltage-gated K channels are
found in the _____ cells and contribute to the
_____ phase of the action potential.

• autorhythmic and contractile depolarization
• autorhythmic depolarization
• contractile depolarization
• contractile plateau
• autorhythmic and contractile repolarization

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In myocardium, voltage-gated Na channels are
found in the _____ cells and contribute to the
_____ phase of the action potential.

• autorhythmic and contractile depolarization
• autorhythmic depolarization
• contractile depolarization
• contractile plateau
• autorhythmic and contractile repolarization

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Calcium ions play a direct role in the action
potentials of

• all myocardium and neurons
• autorhythmic myocardium
• contractile myocardium
• neurons
• all myocardial cells

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Student Presentations
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Next Class Contraction of Heart Tissue

• Chapter 14 470-472
• Ryanodine Receptor
• Actin-Myosin-troponin-tropomyosin
• Sarcoplasmic reticulum ATP-ase
• Hill coefficient
• Review skeletal muscle physiology