QS Study

The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. The heart size is estimated by comparing the transverse diameter of the cardiac silhouette with the transverse diameter of the thoracic cage seen on the frontal radiograph.

Blood supply of heart

The heart receives its own supply of blood from the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet. These arteries and their branches supply all parts of the heart muscle with blood.

Arterial supply

By 2 coronary arteries –

  1. Right coronary artery,
  2. Left coronary artery.

Inner 0.5 mm muscle mass is supplied by blood in the cardiac chamber.

Right coronary artery

Arise from anterior aortic sinus. You can see this branch on the right margin of the heart coming off the right coronary artery. This is called the right marginal branch. That’s the first branch.

Branch: Those arise from the 1st segment:

(a) Ventricular rami –

  • Right conus artery — supply infundibulum.
  • Right anterior ventricular rami — supply stembeostal wall of the right ventricle.

Right marginal artery – inferior border of right ventri.

(b) Atricle rami Supply myocardium of right atrium.

S.A. nodal artery belongs to atrial rami in 65% cages.

Those arising from the 2nd segment:

  1. Right posterior ventricular rami: supply diaphragmatic surface of the right ventricle.
  2. Posterior interventricular branch: Anastomoses with an anterior interventricular branch of the left coronary artery.

Septal rami: posterior inferior 1/3 rd of ventricular septum.

  1. Right posterior rami: supply posterior surface of both right & left atria.

Fig: Blood supply of Heart

Left coronary artery

Arises from left posterior aortic sinus. The first branch which you can see running down the anterior interventricular sulcus is the anterior interventricular artery, otherwise known as the left anterior descending artery. It is divided into the following 2 branches.

Anterior interventricular artery: Gives –

Anterior ventricular rami 2 types –

(a) Left ventricular rami: Diagonal and belongs to this.

(b) Right ventricular rami: Supply infundibulum of the right ventricle.

Septal rami: Supply anterior superior 2/3 of ventricular septum.

  1. Circumflex artery: Branches –
  2. Atrial & ventricular rami.
  3. S. A. nodal artery – in 35% cases.
  4. Left marginal artery,
  5. Posterior interventricular artery.
  6. Kugle’s artery.
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