BIOC33/CC4 Cardiovascular System (Lectures 1-4) Study Guide (2013)
Lecture 1: Electrical Conduction within the Heart
The Conduction System of the Heart
1. What is the pathway of electrical conduction in the heart?
2. Which changes in ionic conductance (permeability) accompany the various phases of the
1. 2. 4.
a) In zone 1, a decrease in K and an increase in PNa In zone 2, an increase in PCa
b) In zone 1, a decrease in PKand an increase in PCa In zone 2, an increase in PNa
c) In zone 3, a large increase in Na: In zone 4, an increase inKP and a decrease in Ca
d) In zone 3, a large increase in P : In zone 4, an increase in P and a decrease in P
Ca K Na
e) A and D
3. The action potential that travels along the conduction pathway of the heart moves upward into the
ventricles (from the apex of the heart) via the ?
a) AV node
b) SA node
c) Purkinje Fibres
d) Atrioventricular valves
e) Bundle of His 2
Lecture 2: Cardiac Action Potential and the Electrocardiogram
The Cardiac Action Potential
Standard Bipolar Limb Leads and Einthoven’s Law
Components of the ECG Wave
Correlation of the ECT Components with the Electrical Conduction Through the Heart
Segments of the ECG Trace
1. Which changes in ionic conductance (permeability) accompany the various phases of the cardiac
2. What do the different components of the ECG represent (i.e., T wave)?
3. Which changes in ionic conductance (permeability) DO NOT accompany the various phases of
the cardiac action potential?
a) In zone 0, an increase in P
b) In zone 1, a decrease in PNa a decrease in PKand an increase in P Ca
c) In zone 2, a decrease in Naand an increase in P Ca
d) In zone 3, an increase in K and a decrease in PCa
e) C and D
4. The P and T waves of the ECG represent and , respectively.
a) Ventricular repolarisation and atrial depolarisation.
b) Atrial depolarisation and atrial repolarisation.
c) Ventricular depolarisation and atrial repolarisation.
d) Atrial depolarisation and ventricular repolarisation.
e) Atrial depolarisation and ventricular depolarisation. 3
5. The following ECG trace is representative of what cardiac disorder?
a) Atrial flutter.
b) Atrial fibrillation.
c) Ventricular fibrillation.
d) Wandering atrial pacemaker.
e) Second degree heart block. 4
Lecture 3: ECGs, Electrical Axis of the Heart and the Cardiac Cycle
ECG and Arrhythmias Continued
Bundle Branch Block
The Electrical Axis of the Heart
Definition of the Electrical Axis
Diagnostic Uses of the Electrical Axis
Calculating the Electrical Axis
The Cardiac Cycle
Opening and Closing of Heart Valves
Heart Valve Disease
Pressure and Volume Changes during the Cardiac Cycle
Late Diastole (Ventricular Filling)
Early Systole (Isovolumetric Contraction)
Late Systole (Ventricular Ejection)
Early Diastole (I