Chambers of The Heart and Conducting System

Question 1

What are the components of the Right Atrium?

Answer 1

1. Crista Terminalis
2. Sulcus Terminalis
3. Pectinate Muscles forms rough anterior wall
4. Fossa Ovalis
5. Smooth Posterior Wall

Question 2

What is the Crista Terminalis?

Answer 2

Groove that separates the rough anterior wall and the smooth posterior wall of the atrium internally

Question 3

What is the Sulcus Terminalis?

Answer 3

Groove that separates the rough anterior wall and the smooth posterior wall of the atrium externally

Question 4

What is the Fossa Ovalis and it’s embryological significance?

Answer 4

It is a remnant of the Foramen Ovale, which in the foetus allows blood to flow between the left and right atrium.

Question 5

What are the components of the Right and Left Ventricles?

Answer 5

1. Papillary Muscles
2. Trabeculae Carnae
3. Chordae Tendinae

Question 6

What is the importance of the Chordae Tendinae?

Answer 6

They hold the AV valves closed during ventricular systole to prevent the ‘blowback’ of the valves

Question 7

What is in the Right Ventricle but not the Left Ventricle?

Answer 7

Septomarginal Trabecula/ Moderator Band- Contains the Right bundle of His, involved in the conducting system of the heart

Question 8

What is the function of the conducting system of the heart?

Answer 8

Initiate and coordinates contraction of the myocardium

Question 9

Describe the Conduction Pathway of the heart

Answer 9

SA node–> Internal Pathways–> AV node–> Bundle of His–> Purkinje Fibres

Question 10

What is the function of the AV node?

Answer 10

Delay the impulse so that the atria contracts before the ventricles

Question 11

What is the innervation of the heart?

Answer 11

1. Parasympathetic–> Vagus Nerve (Branches from the right & left vagus nerves in the neck and thorax, as well as the recurrent laryngeal branch of the vagus)–> causes bradycardia
2. Sympathetic Chain from cervical and thoracic regions on both sides–> cause tachycardia