NR 340 Exam 2 Study
Guide | Critical Care
Nursing Review & Key
Concepts
(Complete solutions and resources for the course exam)
, Exam 2 Study Guide-Critical Care j j j j
Basic Dysrhythmia Interpretation & Mgmt-Ch 7
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Blood Flow Review
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Basic Electrophysiology
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• Automaticity-The ability for the heart muscle to generate it's own electrical activity
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o Pacemaker Cells arise naturally from the SANode
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o Electrolytes involved are K+, Na+, & Ca+ j j j j j j
CardiacAction Potentials
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• Depolarization-occurs when charge is more (+) j j j j j
o Pwave=atrial depolarization
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o QRS complex=ventricular depolarization
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o contraction
o Systole
• Repolarization-recharging period when charge is more (-) j j j j j j
o Twave=ventricular repolarization
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o filling
o Diastole
• Electrical + Mechanical=Cardiac Contraction
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, • Action Potential Curve
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o See Below-Sodium, Potassium, & Calcium flow in & out of the cell at different times allowing
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for charge changes and contraction of heart muscle tissue.
j j j j j j j j
o 4 Phases j
▪ Early Repolarization j
• sodium channels close j j
▪ Phase 2-Plateau Phase j j
• potassium leaves cell j j
▪ Phase 3-Rapid Repolarization j j
• calcium channels close j j
• potassium returns into cell quickly j j j j
▪ Phase 4-Resting Phase (polarized state) j j j j
• active transport through the Na-K pump begins restoring K to inside the cell &
j j j j j j j j j j j j j j
sodium to the outside of the cell j j j j j j
• cell membranes become impermeable to sodium j j j j j
• Potassium may move in & out of the cell j j j j j j j j
Intrinsic Rates of Conduction Pathway
j j j j
• SANode j
o natural pacemaker j
o 60-100 bpm j
• AVNode j
o takes over as pacemaker if SAnode can't do the job
j j j j j j j j j j
Guide | Critical Care
Nursing Review & Key
Concepts
(Complete solutions and resources for the course exam)
, Exam 2 Study Guide-Critical Care j j j j
Basic Dysrhythmia Interpretation & Mgmt-Ch 7
j j j j j
Blood Flow Review
j j
Basic Electrophysiology
j
• Automaticity-The ability for the heart muscle to generate it's own electrical activity
j j j j j j j j j j j
o Pacemaker Cells arise naturally from the SANode
j j j j j j j
o Electrolytes involved are K+, Na+, & Ca+ j j j j j j
CardiacAction Potentials
j j
• Depolarization-occurs when charge is more (+) j j j j j
o Pwave=atrial depolarization
j j
o QRS complex=ventricular depolarization
j j
o contraction
o Systole
• Repolarization-recharging period when charge is more (-) j j j j j j
o Twave=ventricular repolarization
j j
o filling
o Diastole
• Electrical + Mechanical=Cardiac Contraction
j j j
, • Action Potential Curve
j j
o See Below-Sodium, Potassium, & Calcium flow in & out of the cell at different times allowing
j j j j j j j j j j j j j j j
for charge changes and contraction of heart muscle tissue.
j j j j j j j j
o 4 Phases j
▪ Early Repolarization j
• sodium channels close j j
▪ Phase 2-Plateau Phase j j
• potassium leaves cell j j
▪ Phase 3-Rapid Repolarization j j
• calcium channels close j j
• potassium returns into cell quickly j j j j
▪ Phase 4-Resting Phase (polarized state) j j j j
• active transport through the Na-K pump begins restoring K to inside the cell &
j j j j j j j j j j j j j j
sodium to the outside of the cell j j j j j j
• cell membranes become impermeable to sodium j j j j j
• Potassium may move in & out of the cell j j j j j j j j
Intrinsic Rates of Conduction Pathway
j j j j
• SANode j
o natural pacemaker j
o 60-100 bpm j
• AVNode j
o takes over as pacemaker if SAnode can't do the job
j j j j j j j j j j
