6

Question 1

Contraction of the atria and ventricles is
coordinated by specialized cardiac muscle cells
in the heart wall that form the

Answer 1

CONDUCTION SYSTEM

Question 2

The conduction system of the heart includes the

Answer 2

Sinoatrial node,atrioventricular node, atrioventricular bundle, right and left bundle brances and Purkinje fibers

Question 3

• in RA
• where action potential originates
• functions as pacemaker
• large number of Ca2+ channels

Answer 3

SINOATRAL NODE

Question 4

• located in the lower portion of the right atrium
• action potentials from SA node sent to this node
• action potentials spread slowly through it
• slow rate of action potential conduction allows the
  atria to complete their contraction before action
  potentials are delivered to the ventricles

Answer 4

Atrioventricular node

Question 5

• action potentials from AV node travel to AV bundle
• AV bundle divides into a left and right bundle branches

Answer 5

ATRIOVENTRICULAR BUNDLE

Question 6

• at the tips of the left and right bundle branches, are
  Purkinje fibers
• Purkinje fibers pass to the apex of the heart and then
  extend to the cardiac muscle of the ventricle walls
• action potentials are rapidly delivered to all the cardiac
  muscle of the ventricles

Answer 6

PURKINJE FIBERS