Question - What are the Thebesian veins?

Answered by: Roger Parker  |  Category: General  |  Last Updated: 19-06-2022  |  Views: 990  |  Total Questions: 14

The smallest cardiac veins (or Thebesian veins) are minute valveless veins in the walls of all four heart chambers. The veins are sometimes accurately referred to as vessels, but they are frequently confused with a distinct set of artery connections eponymously referred to as the "vessels of Wearn". The coronary veins return deoxygenated blood from the myocardium back to the right atrium. Most venous blood returns via the coronary sinus. Coronary venous anatomy is highly variable, but is generally comprised of three groups: cardiac veins which drain into the coronary sinus: great cardiac vein. The valve of the coronary sinus (Thebesian valve) is a semicircular fold of the lining membrane of the right atrium, at the orifice of the coronary sinus. It is situated at the base of the inferior vena cava. The valve may vary in size, or be completely absent. coronary sinus

There are three systems of the major cardiac veins: tributaries of the coronary sinus, anterior cardiac veins, atrial cardiac veins. Their openings lie in a circle-like arrangement between the ostia of both caval veins and just above the tricuspid valve.

Anterior Veins: Near the left atrium, the great cardiac vein veers to the left and enters the coronary sulcus (= between the left atrium and ventricle), where it extends to the back side of the heart.

Function: The cardiac veins returns deoxygenated blood (containing metabolic waste products) from the myocardium to the right atrium. This blood then flows back to the lungs for reoxygenation and removal of carbon dioxide.

The right coronary artery specifically provides blood to the right atrium, heart ventricles, and the cells in the right atrial wall, which are called the sinoatrial node.

The great cardiac vein (GCV) runs in the anterior interventricular groove and drains the anterior aspect of the heart where it is the venous complement of the left anterior descending artery. It is the main tributary of the coronary sinus.

The small cardiac vein runs in the coronary sulcus between the right atrium and ventricle and opens into the right extremity of the coronary sinus. It receives blood from the posterior portion of the right atrium and ventricle. It may drain to the coronary sinus, right atrium, middle cardiac vein, or be absent.

Coronary venous anatomy is highly variable, but is generally comprised of three groups: cardiac veins which drain into the coronary sinus: great cardiac vein. middle cardiac vein.

The right coronary artery supplies blood to the right ventricle, the right atrium, and the SA (sinoatrial) and AV (atrioventricular) nodes, which regulate the heart rhythm. Together with the left anterior descending artery, the right coronary artery helps supply blood to the middle or septum of the heart.

The thebesian veins are most abundant in the right atrium and least in the left ventricle. They drain the myocardium and run a perpendicular course to the endocardial surface, directly connecting the heart chambers to the medium-sized, and larger coronary veins.

The pulmonary valve (sometimes referred to as the pulmonic valve) is the semilunar valve of the heart that lies between the right ventricle and the pulmonary artery and has three cusps.

The valves present in the mammalian heart are tendinous cords. (2) Haversian valve: Present in human but absent in rabbit. It is present over the opening of precaval vein and allows the passage of blood in right auricle.

The fossa ovalis is a depression in the right atrium of the heart, at the level of the interatrial septum, the wall between right and left atrium. The fossa ovalis is the remnant of a thin fibrous sheet that covered the foramen ovale during fetal development.

Koch's triangle, named after the German pathologist and cardiologist Walter Karl Koch, is an anatomical area located in the superficial paraseptal endocardium of the right atrium, which its boundaries are the coronary sinus orifice, tendon of Todaro, and septal leaflet of the right atrioventricular valve.

The anterior cardiac veins are a group of parallel coronary veins that course over the anterior surface of the right ventricle, draining it and entering directly into the right atrium. They may occasionally drain into the small cardiac vein.