Diagram of the heart

External configuration:

• circumferential groove: divides the heart into 2 parts, one-third posterior and two-thirds anterior (atrium level, ventricular level)
• longitudinal groove: divides the heart into right and left halves

Internal configuration: the heart is divided into 4 cavities forming two parts without any communication

• right heart: the right atrium receives blood and passes it into the right ventricle through the tricuspid valve, the right ventricle ejects blood into the pulmonary artery trunk through the pulmonary valve
• left heart: the left atrium receives blood coming from the pulmonary veins and ejects it into the left ventricle through the mitral valve, the left ventricle will eject it into the aorta through the aortic valve

Structure of the heart:

• endocardium: lines the heart cavities and all the elements contained within them
• myocardium: muscular layer whose thickness is not uniform
• pericardium: visceral layer and parietal layer that encircle a completely closed virtual cavity