Questions and Answers
What is the primary effect of the fight or flight response on the myocardium?
How do coronary arterioles respond to hypoxia?
What term describes the increase in blood flow to the myocardium due to heightened metabolic activity?
What starts the coronary arterial circulation?
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What mainly composes the cardiac veins?
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What primarily controls blood flow through the coronary circulation?
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What is the primary function of coronary circulation?
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Which artery supplies the anterior 2/3 of the interventricular septum?
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What does the left coronary artery primarily supply?
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Which branch of the right coronary artery supplies the right ventricle?
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The posterior descending artery supplies which of the following structures?
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What is an anastomosis in coronary circulation?
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The left circumflex artery primarily supplies which areas?
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Where does the right coronary artery originate?
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Why is coronary circulation essential?
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What type of circulation occurs when the posterior descending artery branches off the right coronary artery?
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During which phase of the heart cycle is blood flow to the coronary arteries briefly occluded?
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Where do the cardiac veins empty their deoxygenated blood?
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What is the function of adenosine in coronary blood flow regulation?
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Which of the following veins runs through the anterior interventricular sulcus?
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What is the primary factor controlling blood flow in the coronary circulation?
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Which variation of coronary artery circulation is the rarest?
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Which artery is responsible for supplying blood specifically to the left side of the heart?
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What happens when the sympathetic nervous system is activated?
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What is the role of the anterior cardiac veins?
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Study Notes
Coronary Circulation Overview
- Movement of blood through vessels supplying the myocardium, the heart muscle.
- Myocardium requires a constant supply of oxygen and nutrients while efficiently eliminating waste.
Coronary Circulation System
- Comprises coronary arteries and veins.
- Left and right coronary arteries branch off from the base of the aorta, delivering oxygenated blood.
Left Coronary Artery
- Follows the left coronary sulcus; essential for supplying blood to the heart.
- Divides into:
- Left Anterior Descending (LAD) Artery: Supplies anterior 2/3 of the interventricular septum and anterior left ventricle.
- Left Circumflex (LCX) Artery: Circles around the left side, supplying the left atrium and posterior left ventricle walls.
Right Coronary Artery
- Travels along the coronary sulcus; crucial in supplying the heart's electrical nodes.
- Branches into:
- Right Marginal Artery: Supplies the right ventricle.
- Posterior Descending Artery (PDA): Supplies the posterior 1/3 of the interventricular septum and posterior left ventricle walls.
Anatomical Variations
- Variability in coronary artery layouts exists.
- Right-Dominant Circulation: PDA branches from the right coronary artery; most common.
- Left-Dominant Circulation: PDA branches from the left circumflex artery; less common.
- Codominant Circulation: PDA branches from both arteries; rare.
Epicardial Vessels
- Coronary arteries located in the epicardium.
- Blood supply to myocardium is affected by cardiac cycles:
- Compression during systole restricts flow.
- Relaxation during diastole allows for enhanced blood flow.
Cardiac Veins
- Responsible for returning deoxygenated blood to the lungs.
- Follow paths similar to coronary arteries:
- Great Cardiac Vein: Anterior interventricular sulcus.
- Middle Cardiac Vein: Posterior interventricular sulcus.
- Small Cardiac Vein: Along inferior right heart margin.
- All drain into the coronary sinus, which empties into the right atrium.
Blood Flow Dynamics
- Primarily regulated by local metabolic factors (adenosine, oxygen levels).
- Sympathetic nervous system has a minor role.
- Increased myocardial activity (e.g., stress) leads to greater oxygen consumption and hypoxia, causing coronary arterioles to vasodilate.
Active Hyperemia
- Caused by an increase in blood flow due to heightened metabolic demand.
Coronary Circulation Summary
- Essential for supplying blood to the myocardium, ensuring heart muscle receives necessary nutrients and oxygen.
- Cardiac veins supplemented by metabolic regulation of blood flow are crucial for maintaining cardiac health.
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Description
This quiz covers the essential concepts of coronary circulation, including the structure and function of coronary vessels. It highlights the importance of myocardial blood supply, the role of cardiomyocytes, and the exchange of substances necessary for heart health. Test your understanding of how blood moves through the heart's vessels.
