Organisation and Chambers of the Heart

Question 1

What is the role of the left and right auricles?

Answer 1

Increase the capacity of the atrium and so also increase the volume of blood that it is able to contain

Question 2

What chamber forms the base of the heart?

Answer 2

LA

Question 3

Anterior to what tubular structure does the LA lie?

Answer 3

Oesophagus

Question 4

What chamber forms the apex of the heart?

Answer 4

LV

Question 5

What is the RA composed of?

Answer 5

Opening for SVC, coronary sinus, IVC
Right auricle
Musculi pectinati
Crista terminalis
Tricuspid valve
Fossa ovalis
Interatrial septum

Question 6

What is the fossa ovalis a remnant of?

Answer 6

The foramen ovale in the foetus

Question 7

What function does the foramen ovale perform?

Answer 7

Allows respiration and circulation independent from the mother

Question 8

What is the RV composed of?

Answer 8

Aorta
Right auricle
Pulmonary trunk
Pulmonary valve
Interventricular septum 
Septomarginal trabeculum
Papillary muscles (X3)
Trabeculae carneae
Chordae tendineae

Question 9

What is the septomarginal trabeculum also known as?

Answer 9

Moderator band

Question 10

What are the 2 things the septomarginal trabeculum does?

Answer 10

It connects the intereventricular septum with the anterior of the RV and carries a portion of the cardiac bundle to the anterior walls of the RV

Question 11

What are the papillary muscles?

Answer 11

A specialised form of trabeculae carneae

Question 12

What do the papillary muscles do?

Answer 12

They attach to the cusps of AV valves (bicuspid and tricuspid) via the chordae tendineae and contract to prevent inversion of prolapse of these valves on ventricular contraction

Question 13

What does the trabecular carneae do?

Answer 13

Prevent inversion of valve and allows a strong contraction allowing heart to pump effectively

Question 14

What does the chord tendineae do?

Answer 14

Papillary muscles connect to these, which attach to the valves. The contraction of the papillary muscles opens these valves and on relaxation of the papillary muscles the valves close

Question 15

How many cusps make up the tricuspid valve? How many papillary muscles are found in the RV?

Answer 15

3 in both (see the correlation)

Question 16

Compare the thickness of the RV wall with that of the LV: What is thickest? By how many times? Why?

Answer 16

LV is thickest by 3 times. The LV has to pump blood all the way around the body, but the R only has to pump to the lungs

Question 17

What is the LA composed of?

Answer 17

Superior and inferior pulmonary veins

Bicuspid (mitral) valve = 2 cusps

Question 18

What does the bicuspid valve do?

Answer 18

Valve which guards the entry from the LA to LV

Question 19

What is the LV composed of?

Answer 19

Opening for aorta
Pulmonary trunk
Left auricle
Interventricular septum
Aortic valve
Bicuspid valve
Chordae tendineae
Papillary muscles
Trabecular carneae

Question 20

How many cusps make up the bicuspid valve? How many papillary muscles are found in the LV?

Answer 20

2 in both (see the correlation)