Electrical signals Traveling through the heart

Question 1

1 SA node fires

Answer 1

-The pacemaker that initiates each H beat & determines H rate

Question 2

2 SA node signals

Answer 2

• Spread through the atria

- Excitation spreads through atrial myocardium

Question 3

3 AV node fires

Answer 3

• Node acts as an electrical gateway to the ventricles

- Fibrous skeleton acts as insulator to prevent current to get to the ventricles

Question 4

4 Excitation spreads

Answer 4

• Down AV bundle (Bundle of His)
• Signals leave AV node
• Bundle soon forks into left & right branches
  
  • Enter interventricular septum & descend toward apex

Question 5

5 Purkinje Fibers

Answer 5

• Distribute excitation through ventricular myocardium

- Nerve like process that arise from the lower end of the bundle branches and turn upward to ventricular myocardium