The Cardiovascular System

Intrinsic Conduction System1. The intrinsic conduction system consists of __autorhythmic cardiac______ cells that initiate and distribute __impulses___ throughout the heart. 2. The intrinsic conduction system coordinates heart activity by determining the direction and speed of _heart depolarization___. This leads to a coordinated heart contraction. 3. List the functions for the following parts of the intrinsic conduction system: a. SA Node __initiates the depolarizing impulse and sets the pace for the entire beat___ b. Internodal Pathway __link between the SA node and the AV node__ c. AV Node __delay occurs allowing atria to contract___ d. AV Bundle (Bundle of His) _link between atria and ventricles__ e. Bundle Branches __convey impulses down the interventricular septum___ f. Purkinje Fibers ___convey the depolarization throughout the ventricular walls_____4. The action potentials spread from the autorhythmic cells of the intrinsic conduction system (electrical event) to the _contractile__ cells. The resulting mechanical events cause a heartbeat.5. A tracing of the electrical activity of the heart is called a/an __electrocardiogram__.6. What do the following wave forms reflect? . P wave ___atrial depolarization___ b. QRS complex ___ventricular depolarization____ c. T wave __ventricular repolarization___7. In a normal ECG wave t racing, atrial repolarization is hidden by __QRS Complez__.8. Note: Electrical events lead to mechanical events. For example, the P wave represents __atrial_ depolarization, which leads to atrial _contraction___.9. A left bundle branch block would have a wider than normal wave for the __QRS complex_. (Quiz section) 10. An abnormally fast heart rate (over 100 beats per minute) is called: __tachycardia___. (Quiz section)