𝐍𝐀𝐓'🤿 :
The heart works as a double, continuous muscular pump that beats approximately 100,000 times a day to keep blood constantly moving throughout the body. Physiologically, this organ is divided into four cavities: two upper ones called atria, which receive blood, and two lower ones called ventricles, which expel it. The cycle begins when deoxygenated blood from throughout the body returns to the heart through the vena cavae and enters the right atrium. This cavity contracts and pushes the blood through the tricuspid valve into the right ventricle, which, upon contracting, sends the blood to the lungs via the pulmonary artery; there, the blood releases carbon dioxide and is recharged with fresh oxygen. Once oxygenated, the blood returns to the heart through the pulmonary veins and enters the left atrium. From there, it passes through the mitral valve into the left ventricle, which is the thickest and most powerful cavity of the heart, responsible for pumping blood with great force into the aorta to distribute it throughout the body. All this mechanical movement is perfectly coordinated by an intrinsic electrical system that generates its own impulses; the electrical journey begins at the sinoatrial node, the natural pacemaker located in the right atrium, which sends a signal for both atria to contract simultaneously. This current then travels to the atrioventricular node and spreads rapidly through the ventricles via the bundle of His and the Purkinje fibers, causing ventricular contraction. This cyclical process consists of two main phases: diastole, which is the moment of relaxation when the cavities fill with blood, and systole, which is the phase of contraction and emptying, thus ensuring a vital, uninterrupted flow. Copy and paste 🤍🥹
2026-10-10 16:32:16