Coronary arteries Anatomy / Blood supply of Heart / Arterial supply of heart : Animation

Summary

This script delves into the arterial supply of the heart, detailing the coronary arteries' origins, courses, and branches. It explains the distribution of the right and left coronary arteries, their roles in supplying blood to different parts of the heart, and the clinical implications of their obstruction, such as angina pectoris and myocardial infarction. The script also covers the venous drainage of the heart, highlighting the coronary sinus and its tributaries, which are crucial for understanding cardiac function and related pathologies.

Takeaways

• 🌟 The heart is primarily supplied by the right and left coronary arteries, which originate from the ascending aorta above the aortic valve.
• 🔍 The right coronary artery (RCA) runs in the right atrioventricular groove and supplies the anterior surface of the pulmonary trunk, anterior ventricular branches, and atrial branches.
• 📍 The left coronary artery (LCA) branches into the anterior interventricular artery and the circumflex artery, supplying various parts of the heart including the interventricular septum and left ventricle.
• 💊 Angina pectoris is a condition where narrowed coronary arteries reduce blood supply to the heart, causing chest pain during exertion that can radiate to the arm and shoulder.
• 🚑 Myocardial infarction, or heart attack, occurs when a coronary artery is suddenly blocked, leading to ischemia and necrosis of the heart muscle.
• ⚠️ The most common sites of coronary artery occlusion are the anterior interventricular artery, right coronary artery, and the circumflex branch of the left coronary artery.
• 🩺 Clinical features of myocardial infarction include chest pain, nausea, vomiting, sweating, shortness of breath, and pain radiating to the arm and jaw.
• 🌀 The venous drainage of the heart involves the coronary sinus and various cardiac veins, which drain blood from the heart walls into the right atrium.
• 🔄 The coronary sinus is the main vein of the heart, receiving blood from the great cardiac vein, middle cardiac vein, and small cardiac vein, among others.
• 🔎 The small cardiac vein accompanies the right ventricular artery and drains into the right end of the coronary sinus, while the oblique vein of the left atrium drains into the coronary sinus from the posterior surface of the left atrium.
• 🔗 The anterior cardiac veins and venae cordis minimae are small veins that drain blood from the right ventricle and all four chambers of the heart, respectively.

Q & A

What are the two main arteries that supply blood to the heart?

The heart is mostly supplied by the right and left coronary arteries, which arise from the ascending aorta.

Where do the coronary arteries originate from?

The right coronary artery originates from the anterior aortic sinus, and the left coronary artery originates from the left posterior aortic sinus, both located immediately above the aortic valve.

What is the anatomical feature that the coronary arteries lie within?

The coronary arteries and their branches run on the surface of the heart, lying within the subpericardial fibrofatty tissue.

How does the right coronary artery course after arising from the ascending aorta?

The right coronary artery first runs forwards between the pulmonary trunk and the right auricle, then descends vertically into the right atrioventricular groove, turns posteriorly at the inferior border of the heart, and terminates by anastomosing with the left coronary artery.

What are the main branches of the right coronary artery and what do they supply?

The right coronary artery supplies the anterior surface of the pulmonary conus, anterior ventricular branches, marginal branch, atrial branches (including the artery of the sinoatrial node in 60% of cases), and posterior ventricular branches, including the posterior interventricular artery.

What is the course of the left coronary artery after it arises from the ascending aorta?

The left coronary artery runs forwards and to the left between the pulmonary trunk and the left auricle, then divides into the anterior interventricular artery and the circumflex artery, which run in their respective grooves to the apex of the heart.

What is the function of the anterior interventricular artery, also known as the left anterior descending artery?

The anterior interventricular artery supplies the interventricular septum, the greater part of the left ventricle, and part of the right ventricle, as well as a part of the left bundle branch.

What clinical condition is associated with narrowed coronary arteries and how is it manifested?

Angina pectoris is associated with narrowed coronary arteries, causing moderate to severe pain in the region of the left precordium that may last up to 20 minutes, often referred to the left shoulder and medial side of the arm and forearm.

What is a myocardial infarction and what are its clinical features?

A myocardial infarction is a blockage of one of the larger branches of a coronary artery, leading to myocardial ischemia and necrosis. Clinical features include chest pain lasting longer than 30 minutes, nausea, vomiting, sweating, shortness of breath, and pain radiating to the arm, forearm, and hand.

Where do the three most common sites of coronary artery occlusion occur and what percentage do they represent?

The three most common sites of occlusion are the anterior interventricular artery (40-50%), the right coronary artery (30-40%), and the circumflex branch of the left coronary artery (15-20%).

How is the venous blood from the heart drained and what is the principal vein involved?

Venous blood from the heart is drained into the right atrium, primarily through the coronary sinus, which is the largest vein of the heart and receives blood from various tributaries including the great cardiac vein, middle cardiac vein, and small cardiac vein.