Impulse conduction

Question 1

normally the initial electrical impulses are generated by what

Answer 1

the SA node

Question 2

the SA node is aka the internal ______

Answer 2

pacemaker

Question 3

sometimes when the SA node fails an external artificial ______ system is required

Answer 3

pacemaker

Question 4

the SA node generates action potentials which spread through the ____ ____ to the ____ ____

Answer 4

through the atrial wall to the AV node

Question 5

propagation of the action potential through the AV nodal region is very slow/fast. What is the benefit of this?

Answer 5

slow - this delay allows time for the atria to empty their contents into the ventricles before ventricular contraction begins.

Question 6

The impulse passes from the AV node into the what?

Answer 6

The bundle of His (atrioventricular bundle)

Question 7

the action potential passes slowly/rapidly down the Bundle of His and its branches into the ______ muscle

Answer 7

rapidly

ventricular

Question 8

the branches of the bundle of His terminate in the ____ ____, transferring the action potentially to ordinary cardiac muscle. What does this result in?

Answer 8

purkinje fibres

This results in rapid, simultaneous excitation of all ventricular muscle cells.