ch 19 cardiac conduction system

Question 1

cardiac conduction system

Answer 1

coordinates the heartbeat;
consists of an internal pacemaker and nerve-like conduction
pathways through myocardium

Question 2

Generates and conducts rhythmic electrical signals in this order

1. sinuatrial (SA) node

Answer 2

patch of modified cardiomyocytes in right atrium
serves as the pacemaker that initiates each heartbeat and determines heart rate

Question 3

Generates and conducts rhythmic electrical signals in this order

2. signals spread throughout

Answer 3

atria

Question 4

Generates and conducts rhythmic electrical signals in this order

3. the atrioventricular (AV) node

Answer 4

patch of modifies cardiomyocytes serves as the eletrical gateway to the ventricles;
fibrous skeleton prevents signals from passing to ventricles by any other route

Question 5

Generates and conducts rhythmic electrical signals in this order

4. atrioventricular (AV) bundle

Answer 5

pathway from which signals leave AV node
forks into right and left bundle branches that traven within interventricular septum

Question 6

Generates and conducts rhythmic electrical signals in this order

5. the subendocardial branches (purkinje fibers)

Answer 6

processes arising from lower end of bundle branches
branch extensively through ventricular myocardium

Question 7

The Cardiac Conduction System

simplified verison

Answer 7

1. SA node fires
2. excitation spreads through atrial myocardium
3. AV node fires
4. excitation spreads down AV bundle
5. subendocardial branches distribute excitation through ventricular myocardium