Venous drainage of heart

Introduction The venous drainage system of the heart can subdivide into a greater and lesser cardiac venous system (CVS). The Thebesian veins/vessels were first studied by French anatomist Raymond Vieussens and German anatomist Adam Christian Thebesius, from whom they derive their name, who both described the vascular network in their research of the coronary circulation. Structure and Function The Thebesian vessels or veins are embedded in the walls of the heart itself. They serve to drain the myocardium and are present in all four heart chambers. They are more abundant on the right side of the heart and, more specifically, are most abundant in the right atrium. The Thebesian vessels include arteriosinusoidal vessels, venosinusoidal vessels, arterioluminal vessels, and venoluminal vessels. The sinusoidal vessels connect the arterioles and venules with sinusoids first before draining into the chamber lumen. The luminal vessels run perpendicular through the myocardium and provide a direct connection between the arterioles, venules, and the chamber lumen, draining through openings in the endocardial surfacereferred to as the "foramina venarum minimarum," "Vieussens' foramina," or "foramina Thebesii." These vessels are unique to the cardiac circulation, providing an alternative route of nourishment and drainage of the myocardium and contributing to the right to left physiologic shunting of the body's circulation. The Thebesian veins usually measure approximately 0.5 mm in dia...

The blood supplying the tissues of the heart is drained through two main sources: • Coronary sinus and the branches draining to it • Right atrium directly Coronary sinus The main, wide vein that runs from left to right in the posterior part of the coronary sulcus. There are few veins which drain into the coronary sinus: • Small cardiac veins at its right end • Middle cardiac vein • The left posterior ventricular vein and left marginal vein • Oblique vein (of Marshall) • Great cardiac vein at its left Meddists is not endorsed by, directly affiliated with, maintained, authorized, or sponsored by any university. The information displayed is for educational purposes only and does not constitute professional medical advice, diagnosis, treatment, or recommendations of any kind. You should always seek the advice of qualified healthcare professionals with any questions or concerns you may have regarding any medical conditions. Menu • • Preclinical subjects • • • • • • Clinical subjects • • Articles • Introduction • Debrecen study guide (Thorax) • Thoracic wall • Thoracic wall – Introduction • Breasts • Layers and fascia • Muscles of the anterior thoracic wall • Thoracic vertebral column • Ribs • Sternum • Neurovasculature • Neurovasculature • Innervation • Nervous system – Introduction • Vagus nerve • Phrenic nerve • Sympathetic innervation • Great vessels • Azygos-Hemiazygos System • Lymphatics • Respiratory system • Lungs • Pleura • Neurovasculature • Pulmonary circulation • Tra...

Location: The coronary sinus is located in the posterior portion of the coronary sulcus on the diaphragmatic or posterior surface of the heart. The coronary sinus empties directly into the right atrium near the conjunction of the posterior interventricular sulcus and the coronary sulcus (crux cordis area), located between the inferior vena cava and tricuspid valve; this atrial ostium can be partially covered by a Thebesian valve, although the anatomy of this valve is highly variable. The coronary sinus receives drainage from most epicardial ventricular veins, including the oblique vein of the left atrium (and other left and right atrial veins), the great cardiac vein, the posterior vein of the left ventricle, the left marginal vein, and the posterior interventricular vein. The length of the coronary sinus in adults can vary from 15 to 65 mm. Function: The coronary sinus serves as the primary collector of cardiac venous blood. Importance in cardiovascular diseases: The delivery of cardioplegia through the coronary sinus has been proven to be safe and effective in myocardial protection, and even superior to the traditional method of antegrade cardioplegia, especially in patients with coronary artery disease. Importance in device delivery: Balloon catheters can be placed coronary sinus to deliver therapeutics, cardioplegia buffers, or contrast agents, to obtain venograms of the heart. Numerous device have also been deployed in the coronary sinus as a means to structurally rem...

Mnemonic: CAT 1. Coronary sinus (50%): Drains blood from left side of heart → Thebesian valve → Right Atrium • Location: Posterior coronary (atrio-ventricular) sulcus • Tributaries: • Left marginal vein → Great cardiac vein (anterior interventricular sulcus) → Coronary sinus • Right marginal vein → Small cardiac vein (right posterior coronary sulcus) → Coronary sinus • Middle cardiac vein (posterior interventricular sulcus) → Coronary sinus • Oblique vein of left atrium (oblique vein of Marshall) • Posterior vein of left ventricle

When your veins have trouble sending blood from your limbs back to the heart, it’s known as venous insufficiency. In this condition, blood doesn’t flow back properly to the heart, causing blood to pool in the veins in your legs. Your arteries carry blood from your Several factors can cause venous insufficiency, though it’s most commonly caused by Even if you have a Venous insufficiency is most often caused by either blood clots or varicose veins. In healthy veins, muscles pump a continuous flow of blood from the limbs back toward the heart. One-way valves within the veins of the legs help prevent the backflow of blood. The most common causes of venous insufficiency are previous cases of blood clots and varicose veins. When forward flow through the veins is obstructed — such as in the case of a blood clot — blood builds up below the clot, which can lead to venous insufficiency. In varicose veins, the valves are often missing or impaired, and blood leaks back through the damaged valves. In some cases, weakness in the leg muscles that squeeze blood forward can also contribute to venous insufficiency. Venous insufficiency is more common in women than in men. It’s also more likely to occur in adults over the age of 50. Other risk factors include: • • • • • • • • swelling of a superficial vein (phlebitis) • family history of venous insufficiency • sitting or standing for long periods of time without moving Symptoms of venous insufficiency include: • swelling of the legs or ankle...

Veins are a type of blood vessel that return deoxygenated blood from your organs back to your heart. These are different from your arteries, which deliver oxygenated blood from your heart to the rest of your body. Deoxygenated blood that flows into your veins is collected within tiny blood vessels called capillaries. Capillaries are the smallest blood vessels in your body. Oxygen passes through the walls of your capillaries to your tissues. Carbon dioxide can also move into your capillaries from the tissue before entering your veins. The venous system refers to the network of veins that work to deliver deoxygenated blood back to your heart. The walls of your veins are made up of three different layers: • Tunica externa. This is the outer layer of the vein wall, and it’s also the thickest. It’s mostly made up of connective tissue. The tunica externa also contains tiny blood vessels called vasa vasorum that supply blood to the walls of your veins. • Tunica media. The tunica media is the middle layer. It’s thin and contains a large amount of collagen. Collagen is one of the main components of connective tissue. • Tunica intima. This is the innermost layer. It’s a single layer of endothelium cells and some connective tissue. This layer sometimes contains one-way valves, especially in the veins of your arms and legs. These valves prevent blood from flowing backward. Veins are often categorized based on their location and any unique features or functions. Pulmonary and systemic ...

The venous drainage of the cranial cavity differs to the rest of the body as the veins do not run parallel to their corresponding arteries. The dural venous sinuses are the main drainage pathway of venous blood from the cranial cavity to the cardiovascular system via the internal jugular veins. They can be thought of as multiple venous channels that run within the brain, surrounded by walls which are made up of the endosteal and meningeal layers of the dura mater. As mentioned above, the drainage areas of specific intracranial veins differs to the arterial territories of the cerebral arteries. Another important difference to note, is that unlike other veins, these venous sinuses are valveless, which allows for a bidirectional flow of venous blood to and from the intracranial veins. This increased risk of passageway of pathogens or neoplastic cells or thrombus formation. The dural venous sinuses are made up of unpaired sinuses and paired sinuses which mostly drain into the internal jugular veins. In this article, we will explore the anatomy of this drainage pathway. Unpaired Sinuses Fig1. Radiopaedia • Superior sagittal sinus The superior sagittal sinus runs from the foramen caecum of the frontal bone. Within the base of the falx cerebri, it continues along the midline in a sagittal plane in a posterior direction to the internal occipital protuberance, where it joins the confluence of sinuses. Receiving venous blood from many tributaries of the cerebral hemispheres and supe...