Anatomy & Physiology: The Unity of Form and Function, 7th Edition

Published by McGraw-Hill Education
ISBN 10: 0073403717
ISBN 13: 978-0-07340-371-7

Chapter 19 - Section 19.2 - Study Guide - Assess Your Learning Outcomes - Page 740: 11

Answer

The major veins that drain the myocardium play a crucial role in returning deoxygenated blood from the heart muscle to the right atrium of the heart. These veins are collectively referred to as the coronary sinus system. The coronary sinus receives blood from various veins that drain the myocardium. Additionally, smaller veins known as the Thebesian veins, or venae cordis minimae, are scattered throughout the heart muscle and contribute to this drainage. Here's an overview: **Major Veins Draining the Myocardium:** 1. **Great Cardiac Vein:** - The great cardiac vein runs along the anterior interventricular groove (sulcus) and drains the blood from the front of the heart. - It often travels alongside the anterior descending artery (LAD) and merges with the coronary sinus. 2. **Middle Cardiac Vein:** - The middle cardiac vein runs along the posterior interventricular groove (sulcus) and drains the posterior part of the heart. - It often accompanies the posterior descending artery (PDA) and also connects to the coronary sinus. 3. **Small Cardiac Vein:** - The small cardiac vein travels along the right side of the heart, draining the blood from the right ventricle and atrium. - It generally flows into the coronary sinus. **Coronary Sinus:** - The coronary sinus is a larger vein that receives blood from the great cardiac vein, middle cardiac vein, small cardiac vein, and several other smaller veins. - The coronary sinus is located within the coronary sulcus on the posterior surface of the heart, between the left atrium and left ventricle. - It empties into the right atrium, where deoxygenated blood mixes with the systemic venous blood. **Thebesian Veins:** - The Thebesian veins, or venae cordis minimae, are tiny venous channels that are dispersed throughout the heart muscle. - They drain directly into the heart chambers, particularly the ventricles, bypassing the larger coronary vessels. - These veins have variable distribution and contribution to overall venous drainage. **Blood Flow and Function:** The major veins draining the myocardium collect deoxygenated blood rich in waste products from the heart muscle. This blood is eventually transported to the right atrium via the coronary sinus. The right atrium then pumps this deoxygenated blood into the right ventricle to be pumped to the lungs for oxygenation. In summary, the major veins, including the great cardiac vein, middle cardiac vein, and small cardiac vein, along with the coronary sinus, play a critical role in draining deoxygenated blood from the heart muscle. The Thebesian veins supplement this drainage, ensuring effective circulation and waste removal within the heart.

Work Step by Step

The major veins that drain the myocardium play a crucial role in returning deoxygenated blood from the heart muscle to the right atrium of the heart. These veins are collectively referred to as the coronary sinus system. The coronary sinus receives blood from various veins that drain the myocardium. Additionally, smaller veins known as the Thebesian veins, or venae cordis minimae, are scattered throughout the heart muscle and contribute to this drainage. Here's an overview: **Major Veins Draining the Myocardium:** 1. **Great Cardiac Vein:** - The great cardiac vein runs along the anterior interventricular groove (sulcus) and drains the blood from the front of the heart. - It often travels alongside the anterior descending artery (LAD) and merges with the coronary sinus. 2. **Middle Cardiac Vein:** - The middle cardiac vein runs along the posterior interventricular groove (sulcus) and drains the posterior part of the heart. - It often accompanies the posterior descending artery (PDA) and also connects to the coronary sinus. 3. **Small Cardiac Vein:** - The small cardiac vein travels along the right side of the heart, draining the blood from the right ventricle and atrium. - It generally flows into the coronary sinus. **Coronary Sinus:** - The coronary sinus is a larger vein that receives blood from the great cardiac vein, middle cardiac vein, small cardiac vein, and several other smaller veins. - The coronary sinus is located within the coronary sulcus on the posterior surface of the heart, between the left atrium and left ventricle. - It empties into the right atrium, where deoxygenated blood mixes with the systemic venous blood. **Thebesian Veins:** - The Thebesian veins, or venae cordis minimae, are tiny venous channels that are dispersed throughout the heart muscle. - They drain directly into the heart chambers, particularly the ventricles, bypassing the larger coronary vessels. - These veins have variable distribution and contribution to overall venous drainage. **Blood Flow and Function:** The major veins draining the myocardium collect deoxygenated blood rich in waste products from the heart muscle. This blood is eventually transported to the right atrium via the coronary sinus. The right atrium then pumps this deoxygenated blood into the right ventricle to be pumped to the lungs for oxygenation. In summary, the major veins, including the great cardiac vein, middle cardiac vein, and small cardiac vein, along with the coronary sinus, play a critical role in draining deoxygenated blood from the heart muscle. The besian veins supplement this drainage, ensuring effective circulation and waste removal within the heart.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.