Lung (238-248)

Question 1

What structures are found in the hilum of the right and lefts lungs?;

Answer 1

Pulmonarh artery, bronchus, superior and inferor pulmonary veins. Bronchus superior in hilum of right lung however pulmonary artery superior in hilum of left lung.

Question 2

What structures pass in front of and behind the hilum of the lungs?;

Answer 2

Front- phrenic nerve. Behind-vagus nerve, oesophagus, right hilum- azygous vein, left hilum- descending aorta

Question 3

What impressions are formed on the right and the left lungs?;

Answer 3

Right- mostly venous e.g. SVC. Left- mostly arterial e.g. aortic arch and oesophagus

Question 4

What is the function of the pulmonary ligament?;

Answer 4

Allows expansion of pulmonary vessels during breathing & keeps lung attached.

Question 5

What is a bronchopulmonary segment?;

Answer 5

A segment of lung that has pulmonary artery, pulmonary vein , bronchial branch and lymphatics.

Question 6

How many bronchopulmonary segments does each lung have?;

Answer 6

Right lung- at least 10. Left lung- 8 to 10

Question 7

Name the main branches of the right and left cornary arteries;

Answer 7

Right coronary artery (supplies right artium and right ventricle) -> **Right marginal artery ** (anterior surface, supplies right ventricle and apex) and Posterior interventricular artery (Piv) [from RCA in 80% population] (posterior surface, supplies right & left ventricles and the interventricular septum) .

Left coronary artery -> left anterior descending [LAD] (anterior surface, supplies right ventricle, left ventricle and interventricular septum), left marginal artery (anterior surface, supplies left ventricle) and left circumflex artery [give off PIv in 20% population] (posterior surface, supplies left artium and left ventricle)

Question 8

Name the key cardiac (coronary) veins;

Answer 8

Venous drainage mostly through coronary sinus (located on posterior aspect of heart then drains into right atrium).
Main cardiac vein contributaries to coronary sinus are- Great cardiac vein (anterior interventricular vein), Small cardiac vein (anterior surface between right atrium and right ventricle), Middle cardiac vein (posterior interventricular vein), **Posterior cardiac vein ** (posterior surface of left ventricle)

Question 9

What are distinctive features found within the ventricles of the heart?;

Answer 9

Trabeculae carnae (muscular columns- sponge like), Chordae tendinae (fibrous cords attached to the tricuspid valve in right ventricle and mitral valve in left ventricle [3 in right and 2 in left]). Papillary muscles (pull on chordae tendineae to prevent prolapse of valve)

Question 10

What are distinctive features are found in the atrium of the heart?;

Answer 10

Pectinate muscles (rough musclar walls - more prominent right atrium to left [left more smooth]). Fossa ovalis (ovale shaped depression - remnant of foramen ovale). Crista terminalis (rough ridge in right atrium where sinoatrial node is located)

Question 11

Describe the conduction system of the heart;

Answer 11

1. Excitation signal created by SA node.
2. Wave excitation spreads across atria, causing them to contract.
3. Upon reaching AV node signal is delayed.
4. Signal then conduction into bundle of HIS down interventricular septum.
5. Bundle of His and the Purkinje fibres spread the wave impulses along ventricles, causing them to contract.