Synonyms
Cardia, pericardium, epicardium, myocardium, endocardium Medical: Cor
- Pericardium
- Epicardium
- Myocardium
- Endocardium.
The next and by far the thickest layer is the heart muscle (myocardium). It is the actual motor of the cardiovascular system. The muscles are separated from the blood only by a very thin layer of cells (endocardium), which is very smooth on the side facing the cavities (lumen, heart cavities).
The heart comprises four cavities, one right and one left atrium (atrium) as well as one right and one left chamber (ventricle). The cavities are separated from each other by musculature. There is an atrial septum (with the foramen ovale closed after birth), an atrial-ventricular septum on the right and left between the atrium and the ventricle, and the ventricular septum between the two ventricles.
As in the veins of the body, the direction of blood flow in the heart is determined by the heart valves (sail valves, between the atrium and the ventricle, and pocket valves, between the ventricle and the outflow tract). The used (low-oxygen) venous blood from the great circulation of the body enters the right atrium via the superior and inferior vena cava (vena cava superior and inferior vena cava), then through the right sail valve (tricuspid valve = valvula atrioventricularis dexter) into the right ventricle and is pumped from here through the right pocket valve (pulmonary valve) into the pulmonary circulation (small circulation). After it has absorbed oxygen there, it returns to the heart in the left atrium.
From there, it takes the same route as on the right, only through the left valves: through the left sail valve (mitral valve = valvula atrioventricularis sinister) into the left chamber, and is then pumped through the aortic valve into the large circulation of the body. All valves allow blood flow in one direction only. Sail valves are called sail valves because they are shaped like the sails of a sailboat and are attached to the chamber muscles by tendons (papillary muscles, chordae tendinae) – this prevents them from swinging too far back.
The pocket flaps function somewhat differently: they are built in such a way that they are pressed against each other when the blood flow is reversed and therefore cannot penetrate. All four heart valves lie in one spatial plane.
- Main artery (aorta)
- Ventricle
- Coronary arteries
- Atrium (Atrium)
- Vena cava (vena cava)
- Carotid artery (carotid artery)
- Main artery (aorta)
- Left atrium
- Left atrial valve = mitral valve (closed)
- Left heart valve = aortic valve (open)
- Left ventricle
- Right ventricle
- Inferior vena cava (inferior vena cava)
- Right heart valve= pulmonary valve (open)
- Right atrium (atrium)
- Superior vena cava (vena cava superior)
