Regulation O Heart Rhythm

Question 1

What does the heart muscle have?

Answer 1

The ability to contract and relax on its own.

Question 2

What is heart muscle called? What is its purpose?

Answer 2

-Myogenic Muscle
-Safety mechanism to ensure heart will continue to beat if nervous system is damaged.

Question 3

Where is the heart beat initiated?

Answer 3

At a cluster of cells

Question 4

What is the cluster of cells called?

Answer 4

The Sinoatrial node (SA node)

Question 5

Describe the SA node

Answer 5

-50-100 electrical signals per minute.
-Pacemaker
-Waves first pass over the atria, causing the muscles to contract.

Question 6

What do the second mass of signals pass? Where is this located?

Answer 6

The atrioventricular node (AV); located between the right atrium and the right ventricle

Question 7

What goes from the AV node? What are these called?

Answer 7

Conducting fibres run down through the septum to the ventricles. These are called Purkinje fibres.