Heart Physiology Homework

Cardiovascular System: Intrinsic Conduction System

1. The intrinsic conduction system consists of _______________ ____________ cells that initiate and distribute _______________ throughout the heart.

2. The intrinsic conduction system coordinates heart activity by determining the direction and speed of ________________. This leads to a coordinated heart contraction.

3. List the functions for the following parts of the intrinsic conduction system:

a. SA node ____________________________

b. Internodal pathway __________________________

c. SKIP

d. AV bundle (bundle of His) ____________________________

e. Bundle branches __________________________

f. Purkinje fibers ____________________________

4. The action potentials spread from the autorhythmic cells of the intrinsic conduction system (electrical event) to the ______________ cells. The resulting mechanical events cause a heartbeat.

5. A tracing of the electrical activity of the heart is called a/an ________________.

6. What do the following wave forms reflect?

a. P wave ____________________________

b. QRS complex ____________________________

c. T wave ____________________________

7. In a normal ECG wave tracing, atrial repolarization is hidden by the ___________________.

8. Electrical events lead to mechanical events. For example, the P wave represents ____________ depolarization, which leads to atrial _____________.

9. A left bundle branch block would have a wider than normal wave for the ____________.

10. An abnormally fast heart rate (over 100 beats per minute) is called ______________.

Answers

1. autorhythmic cardiac, impulses (action potentials)

2. heart depolarization

3. a. initiates the depolarizing impulse and sets the pace for the entire heart

b. link between the SA node and the AV node

c. SKIP

d. delay occurs allowing atria to...