Atria

Question 1

Where does the pulmonary circulation drain into?

Answer 1

The left atrium through the pulmonary veins

Question 2

Where does the systemic circulation drain into?

Answer 2

The right atrium through the superior and inferior vena cava

Question 3

What is ventricular filling mostly?

Answer 3

Passive

Question 4

When does the atria contract?

Answer 4

Not until the end of diastole

Question 5

What happens to the atria during contraction?

Answer 5

Becomes essential to match the speed of ventricular filling to the increased rate of ventricular contraction

Question 6

Describe the atrioventricular orifice

Answer 6

The aperture in which blood flows from the right atrium to the right ventricle. The tricuspid valve is positioned here

Question 7

Describe the atrioventricular node (AV)

Answer 7

The electrical relay station between the atria and ventricles. It is located in the posteroinferior region of the interatrial septum near the opening of the coronary sinus

Question 8

Describe the crista terminalis (terminal crest)

Answer 8

It is the origin of the pectinate muscles. The sulcus terminalis (on the external surface) acts as a surface marking for the internal crista terminalis

Question 9

Describe the fossa ovalis

Answer 9

An embryological remnant of the foremen ovale.

Question 10

What is the foramen ovale?

Answer 10

Is a hole between the two atria in a foetal heart

Question 11

Describe the interatrial septum

Answer 11

The firbomuscular wall between the left and right atrium. The fossa ovalis and the AV node is located here

Question 12

Describe the opening of the coronary sinus

Answer 12

The coronary sinus is the main cardiac vein. It is where the deoxygenated blood drained from the heart itself returns to the hearts circulation

Question 13

Describe the pectinate muscles (comb like muscles)

Answer 13

These are parallel ridges in the walls of the atrium

Question 14

Describe the right auricle

Answer 14

Also known as the right atrial appendage - it is a muscular pouch that acts to increase the capacity of the atrium

Question 15

Describe the sinoatrial node (SA)

Answer 15

The pacemaker of the heart. It is located in the posterior wall of the right atrium, inferolateral to the opening of the vena cava, along the superior part of the crista terminalis

Question 16

Describe the sulcus terminalis

Answer 16

A shallow depression marking the point of fusion between the venous part of the right atrium and the true right atrium. The crista terminalis sits on the internal surface of this structure

Question 17

What are the features in the left atrium?

Answer 17

Atrioventricular orifice, fossa ovalis, interatrial septum, left auricle and pectinate muscles

Question 18

What is the left auricle also known as?

Answer 18

The left atrial appendage

Question 19

Describe the atrioventricular (left)

Answer 19

The aperture in which blood floes from the left atrium to the left ventricle. The bicuspid (mitral) valve is positioned here

Question 20

What features are found in the right atrium?

Answer 20

Atrioventricular orifice, atrioventricular node, crista terminalis, fossa ovalis, interatrial septum, opening of the coronary sinus, pectinate muscles, right auricle, SA node and sulcus terminalis