The right heart consists of two chambers, the right atrium and the right ventricle, separated by a valve, the tricuspid valve.[9] The right atrium receives most of the blood continuously from the body’s two main veins, the superior vena cava and the inferior vena cava. A small amount of blood remaining from the coronary circulation also drains into the right atrium through the coronary sinus, which opens just above the opening of the inferior vena cava and into the middle.[9] In the wall of the right atrium is an oval-shaped impression known as the fossa ovale, which is the remnant of an opening in the fetal heart called the foramen ovale.[9] Most of the inner surface of the right atrium is smooth, the fossa ovale medial. As for the anterior surface of the right atrium, it has muscular edges called the metatarsal muscles, and these muscles are also present in the right atrial appendage.[9]
The right atrium is connected to the right ventricle by the tricuspid valve.[9] The walls of the right ventricle are lined with trabeculae meatis, which are projections of cardiac muscle covered by the endocardium. In addition to these muscular letters, there is also a bundle of cardiac muscle also covered by the endocardium called the modified striate, which reinforces the thin walls of the right ventricle and plays a crucial role in cardiac transmission. 9] The right ventricle tapers into the pulmonary trunk, where it ejects blood as it contracts. The pulmonary trunk branches into the left and right pulmonary arteries, which carry blood to each lung. The pulmonary valve is located between the right heart and the pulmonary trunk.[9]
