CVS Notes

Question 1

How are the sections of the mediastinum divided?

Answer 1

Superior and inferior - divided by the sternal angle (indicated by T4).
Anterior, middle, and posterior - divisions of inferior.

Question 2

What is cardiac tamponade?

Answer 2

When excess fluid accumulates within the pericardial cavity and increases pressure on the heart wall. The heart has impeded filling and this can lead to cardiac failure.

Question 3

Where do the fibrous and parietal pericardium receive blood from?

Answer 3

The internal thoracic artery, a branch of the subclavian artery.

Question 4

What are the auricles?

Answer 4

Right and left - attached to the anterior surface of the outer walls of their respective atria.
Increases the volume of blood the atria can contain.

Question 5

What is the coronary sinus?

Answer 5

Collects deoxygenated blood from the heart myocardium, and drains blood into the RA.

Question 6

What is the crista terminalis?

Answer 6

Provides the origin for the pectinate muscles.

Question 7

What is the musculi pectinati?

Answer 7

Increases contraction strength.
Acts as RA volume reserve in adverse loading conditions.

Question 8

What is ASD?

Answer 8

A defect in the interatrial septum, allowing pulmonary venous return from the LA to pass directly to the RA.

Question 9

What is the trabeculae carneae?

Answer 9

Prevents inversion of the mitral and tricuspid valves.

Question 10

What is the septomarginal trabeculum?

Answer 10

In the RV.
Contracts the three papillary muscles to prevent tricuspid regurgitation.

Question 11

What are the papillary muscles?

Answer 11

Prevents leakage through the mitral and tricuspid valves during systole.

Question 12

What is the chordae tendineae?

Answer 12

Prevents the cusps of valves from swinging back into the atrial cavity during systole.

Question 13

Where is the blood that supplies the heart drained into?

Answer 13

The cardiac veins, into the coronary sinus (a wide venous channel on the posterior surface of the heart, lying just below the LA).

Question 14

What is the anterior interventricular groove?

Answer 14

Has the LAD.
Continues onto the diaphragmatic surface of the heart (now posterior).

Question 15

Where do the coronary arteries arise from?

Answer 15

From the left and right aortic sinuses (dilations of the ascending aorta, just above the aortic valve).

Question 16

What do the coronary artery branches pierce?

Answer 16

The myocardium.
Branches to surround each cardiac muscle cell.

Question 17

What are end arteries?

Answer 17

Arteries that are the only supply of oxygenated blood for a portion of tissues.

Question 18

What is the ‘widow’s artery’?

Answer 18

The left anterior descending artery.
If occluded, results in MI and mortality.
Cardiac muscle has poor regenerative properties.

Question 19

What are the cardiac veins?

Answer 19

They carry deoxygenated blood from the myocardium to the RA.
Lies alongside the coronary arteries in coronary and interventricular grooves.

Question 20

Where do the cardiac veins drain into?

Answer 20

Great/middle/small - into coronary sinus.
Anterior/smallest (Thebesian) - into RA.

Question 21

What is the ligament of Marshall?

Answer 21

An epicardial vestigial fold that marks the location of the embryologic left SVC.

Question 22

What is the coronary sinus a branch of?

Answer 22

The circumflex artery.
In the coronary sulcus.

Question 23

What are the venae cordis minimae?

Answer 23

Small veins that drain the heart wall directly into each chamber of the heart.

Question 24

What is the lymphatic drainage of the cardiac veins?

Answer 24

Heart wall.
Tracheobronchial.
Bronchopulmonary.
Paratracheal.

Question 25

How do parasympathetic and sympathetic fibres innervate the heart wall?

Answer 25

Autonomic motor fibres in the vagus nerve (P) and in T1-T4 (S) are sent to the heart and coronary arteries, via the cardiopulmonary nerve plexus at the bifurcation of the trachea.

Question 26

What fibres are carried away from the heart?

Answer 26

S - sensory and pain fibres from the heart wall.
P - changes in blood pressure (to the brain).

Question 27

How is heart pain interpreted by the brain?

Answer 27

As coming from the dermatomes T1-T4.
Particularly from the left upper arm.
Angina is referred to upper arm dermatomes (stronger impulses than autonomic ones).

Question 28

What is the fibrous pericardium attached to?

Answer 28

To the diaphragm (inferiorly).

Question 29

What happens to the heart when stood up?

Answer 29

It descends a small amount.
1/3rd of the heart is right of the median plane.
2/3rd of the heart is left of the median plane.

Question 30

Where are the borders of the heart, in relation to intercostal spaces and costal cartilages?

Answer 30

Superior - 2nd right CC to 3rd left CC.
Inferior - 5th right CC to 5th left ICS.
Right - 2nd right CC to 5th right CC.
Left - 3rd left CC to the 5th left ICS.

Question 31

What is the course of the aorta?

Answer 31

Gives major branches to the head, neck, and upper limbs.
Passes inferiorly along the posterior body wall, in front and left of the thoracic and lumbar vertebral bodies, to supply the body wall and organs.

Question 32

What is the descending thoracic aorta?

Answer 32

Pierces the diaphragm at T12 to become the abdominal aorta.

Question 33

How does the abdominal aorta branch?

Answer 33

Into common iliac arteries (L4).
Into interior and exterior iliac arteries (S1).

Question 34

Where do the vessels of the neurovascular bundle of the intercostal space arise from and drain into?

Answer 34

Larger vessels that run vertically along the anterior and posterior chest wall.
The aorta, internal thoracic vessels, SVC.

Question 35

What are the iliac arteries?

Answer 35

Common - lies in the iliac fossae; terminal branches of the abdominal aorta.
External - arises from common iliac arteries; becomes the femoral arteries in the thigh.
Internal - supplies visceral pleura.

Question 36

What are the internal thoracic arteries?

Answer 36

From the subclavian arteries.
Lies anteriorly and parasternally.
Accompanies internal thoracic veins.
Gives off anterior intercostal arteries to ICSs.

Question 37

What does each anterior intercostal artery anastomose with?

Answer 37

Its corresponding posterior intercostal artery.
Anterior - supplies the breast, fibrous pericardium, parietal pleura, and diaphragm.
Posterior - given off by ascending aorta.

Question 38

What do the SVC and IVC drain?

Answer 38

SVC - neck, head, and upper limbs.
IVC - abdominal and pelvic cavities, and lower limbs.

Question 39

What is the SVC?

Answer 39

Located in the anterior right superior mediastinum. Conducts blood upwards into the internal jugular vein.

Question 40

What is the course of the SVC?

Answer 40

Starts behind the lower border of the 1st CC.
Descends vertically behind the 2nd and 3rd ICS.
Drains into the RA at the level of the 3rd CC.

Question 41

What are the tributaries of the IVC?

Answer 41

From bottom to top: I L G R S H.
Iliac, lumbar, gonadal, renal, suprarenal, hepatic.

Question 42

What is the mammary vein?

Answer 42

Drains the anterior intercostal veins to the left and right brachiocephalic veins.

Question 43

What is the azygos venous system?

Answer 43

Drains blood from the posterior intercostal veins to the SVC. Lies immediately adjacent to the thoracic aorta.

Question 44

What are the veins of the azygos venous system?

Answer 44

Azygos - the right of the descending thoracic aorta, drains into the SVC.
Hemiazygos - left side, drains into the azygos vein by crossing left to right at T8/T9.

Question 45

What happens if the mitral valve is incompetent?

Answer 45

Backflow occurs into the LA and pulmonary circulation. Pulmonary pressure increases and pushes plasma out into the alveoli.