L42-coronary Circulation

Question 1

Arterial supply

Answer 1

Right and left coronary arteries

Question 2

Venous drainage

Answer 2

Coronary sinus
Anterior cardiac veins
Thebesian veins(venae cordis minmae)

Question 3

Origin of right coronary artery

Answer 3

Anterior superior aortic sinus of ascending aorta

Question 4

Branches of right coronary artery

Answer 4

1-Marginal branches
Supply anterior free wall of RV
2-acute marginal artery
Between anterior and inferior aspect of RV
3-posterior inter ventricular artery(right posterior descending)
4-SAN
5-AVN

Question 5

How does the right coronary artery terminate

Answer 5

70% as right posterior descending/posterior inter ventricular
30% anastomoses with circumflex branch of left coronary artery

Question 6

Describe sick sinus syndrome

Answer 6

Tachy brady syndrome
Damage to sinus nodal artery
Frequency of generation of cardiac AP becomes random or inappropriate

Question 7

What is the result of damage to artery supplying AVN or bundle of his

Answer 7

Complete heart block

Question 8

What does the right posterior descending supply

Answer 8

Inferior aspect of RV,LV interventricular septum and posterior papillary muscle

Question 9

Origin of left coronary artery

Answer 9

Arises from left posterior aortic sinus of ascending aorta

Question 10

Branches of left coronary artery

Answer 10

1-circumflex branch
2-left anterior descending artery (LAD)
Widow maker
Anterior interventricular artery

Question 11

Describe the circumflex artery

Answer 11

▪️Runs in posterior atrioventricular groove
▪️Gives off marginal branches and obtuse marginal
▪️Ends by anastomosing with right coronary artery

Question 12

Describe the left anterior descending artery

Answer 12

Runs in anterior inter ventricular groove to apex then posterior interventricular groove
Ends by anastomosing with termination of posterior interventricular artery

Question 13

What does the LAD supply

Answer 13

Anterior septal
Anterior lateral
Apical portion of left ventricle and anterior papillary muscle

Question 14

What is the variation of coronary artery branches

Answer 14

Right dominance:
Commonest
Posterior interventricular artery is from right coronary artery
Left dominance:
Least common
Posterior interventricular artery is from circumflex artery

Question 15

What is the coronary sinus

Answer 15

Wide vein that lies between left atrium and left ventricle posteriorly
Receives veins from the heart and then opens in to right atrium

Question 16

What are the veins that drain in to the coronary sinus

Answer 16

1-great cardiac vein
(Vein that lies in anterior interventricular groove)
2-middle cardiac vein
(Lies in posterior interventricular groove)
3-small cardiac vein
(Runs along lower border of heart from left to right)
4-oblique vein of left atrium
5-posterior vein of left ventricle

Question 17

What are the anterior cardiac veins

Answer 17

One or two veins from the front of the ventricle and open directly in to right atrium

Question 18

What are the thebesian veins

Answer 18

Small veins that begin in myocardium of any chamber of any chamber and open directly in to right atrium and right ventricle