Basics

Question 1

Describe the sequence of contraction of the heart?

Answer 1

1. Atria - atrial systole.
2. Ventricle - ventricular systole.

Question 2

What happens to the chambers during diastole?

Answer 2

All four chambers are relaxed.

Question 3

What are the structures that make up the conduction system?

Answer 3

1. SA node.
2. Internodal atrial pathways.
3. AV node.
4. Bundle of His and its branches.
5. Purkinje system.

Question 4

What is the cardiac pacemaker of the heart?

Answer 4

SA node.

Question 5

How is the SA node the cardiac pacemaker?

Answer 5

Its rate of discharge determines the rate at which the heart beats.

Question 6

What is the basic pathway of conduction in the heart?

Answer 6

1. SA node generates impulse.
2. Impulse goes to AV node via atrial pathways.
3. Goes down the bundle of His in the inter-ventricular septum.
4. Via the branches of bundle of His goes via the purkinje fibres to the ventricular muscles.