[Music] arterial supply of the heart the heart is mostly supplied by the two coronary arteries which arise from the ascending aorta immediately above the eye or tick valve the coronary arteries and their branches run on the surface of the heart lying within the sub pericardial fibrofatty tissue anatomically coronary arteries are not and arteries but functionally they behave like end arteries right coronary artery origin the right coronary artery arises from the anterior attic sinus of the ascending aorta immediately above the I Arctic valve course after arising from the ascending aorta the right coronary artery first runs forwards between the pulmonary trunk and the right oracle and then it descends almost vertically into the right atrioventricular groove the right anterior coronary sulcus up to the junction of the right and inferior borders of the heart at the inferior border of the heart it turns posteriorly and runs in the posterior atrioventricular groove up to the posterior interventricular groove and terminates by anastomosing with the left coronary artery branches and distribution right CONUS artery it supplies the anterior surface of the pulmonary CONUS anterior ventricular branches they are two or three and supply the anterior surface of the right ventricle the marginal branch is the largest and runs along the lower margin of the sternal costal surface to reach the apex atrial branches they supply the atria one of the atrial branches the artery of the sinoatrial node supplies the SA node in 60% of cases in 40 percent of individuals it arises from the left coronary artery posterior ventricular branches they are usually to and supply the diaphragmatic surface of the right and left ventricles posterior interventricular artery it runs in the posterior interventricular groove up to the apex it supplies the posterior part of the interventricular septum AV node in 60% cases and right and left ventricles left coronary artery origin the left coronary artery arises from the left posterior I Arctic sinus of the ascending aorta immediately above the I Arctic valve course after arising from the ascending aorta the left coronary artery runs forwards and to the left between the pulmonary trunk and the left auricle it then divides into an anterior interventricular artery also known as left anterior descending artery and runs downwards in the anterior interventricular groove to the apex of the heart it then passes posteriorly around the apex of the heart to enter the posterior interventricular groove to terminate by anastomosing with the posterior interventricular artery a branch of the right coronary artery the circumflex artery winds around the left margin of the heart and continues in the left posterior coronary sulcus up to the posterior interventricular groove where it terminates by anastomosing with the right coronary artery branches and distribution anterior interventricular artery also known as left anterior descending artery it supplies and here you're part of interventricular septum greater part of the left ventricle and part of the right ventricle and a part of left bundle branch circumflex artery it gives a left marginal artery that supplies the left margin of the left ventricle up to the apex of the heart diagonal artery it may arise directly from the trunk of the left coronary artery CONUS artery it supplies the pulmonary CONUS atrial branches they supply the left atrium clinical correlation angina pectoris if the coronary arteries are narrowed the blood supply to the cardiac muscles is reduced as a result on exertion the patient feels moderately severe pain in the region of left procore diem that may last as long as 20 minutes the pain is often referred to the left shoulder and medial side of the arm and forearm in angina pectoris pain occurs on exertion and relieved by rest this is because the coronary arteries are so narrowed that ischemia of cardiac muscle occurs only on exertion myocardial infarction a sudden block of one of the larger branches of either coronary artery usually leads to myocardial ischemia followed by the myocardial necrosis which is myocardial infarction the part of heart suffering from myocardial infarction stops functioning and often causes death this condition is termed heart attack or coronary attack the clinical features of myocardial infarction are as follows a sensation of pressure or sinking and pain in the chest that lasts longer than 30 minutes nausea or vomiting sweating shortness of breath and tachycardia pain radiates to the medial side of the arm forearm and hand sometimes it may be referred to jaw or neck sites of coronary artery occlusion the three most common sites of the coronary artery occlusion are as under anterior interventricular artery or left anterior descending artery is 40 to 50 percent right coronary artery is 30 to 40 percent circumflex branch of the left coronary artery is 15 to 20 percent an important point to be noted here is that myocardial infarction mostly occurs at breast where as angina occurs on exertion anterior interventricular artery or left anterior descending artery is most commonly blocked venous drainage of the heart venous blood from the heart is drained into right atrium by the following coronary sinus anterior cardiac veins vena cordis mini-me also known as the Bayesian veins coronary sinus it is the principal vein of the heart most of the venous blood from the walls of the heart is drained into the right atrium through coronary sinus the coronary sinus is the largest vein of the heart and lies in the posterior part of the atrial ventricular groove it develops from the left horn of the sinus venous and a part of the left common Cardinal vein tributaries the coronary sinus receives the following tributaries great cardiac vein it accompanies anterior interventricular and circumflex arteries to join the left end of the coronary sinus middle cardiac vein it accompanies the posterior interventricular artery to join the coronary sinus near its termination small cardiac vein it accompanies the right ventricular artery in the right posterior coronary sulcus and the right end of the coronary sinus posterior Wain of the left ventricle it runs on the diaphragmatic surface of the left ventricle and joins the sinus to the middle cardiac vein oblique vein of left atrium also known as vein of Marshall it is a small wind which runs downwards on the posterior surface of the left atrium to enter the left end of the coronary sinus it develops from the left common Cardinal vein which is also known as a duct of Q veer right marginal vein it accompanies the marginal branch of the right coronary artery and joins the small cardiac vein or drains directly into the right atrium left marginal vein it accompanies the marginal branch of the left coronary artery and drains into the coronary sinus anterior cardiac veins these are a series of small veins which run parallel to each other across the surface of right ventricle to open into the right atrium vena cordis minimize also known as the Bayesian veins these are extremely small veins in the walls of all four chambers of the heart