The heart

The heart is a muscular organ at the center of the circulatory system, responsible for pumping blood throughout the body. It supplies oxygen and nutrients to tissues and removes carbon dioxide and waste products.🫀
Structure of the Heart:
Four Chambers: Two atria (upper chambers) and two ventricles (lower chambers).

Valves: Tricuspid, pulmonary, mitral, and aortic valves ensure one-way blood flow.

Layers: The heart wall has three layers—epicardium (outer), myocardium (muscular middle), and endocardium (inner).

Pericardium: A protective sac surrounding the heart, containing lubricating fluid.

🔁 How It Works:
Deoxygenated blood enters the right atrium from the body.

It moves to the right ventricle and is pumped to the lungs via the pulmonary artery.

Oxygenated blood returns to the left atrium from the lungs.

It flows into the left ventricle and is pumped out to the body through the aorta.

❤️ Key Facts:
The heart beats about 72 times per minute at rest.

It pumps around 6,000–7,500 liters of blood daily.

It’s roughly the size of a clenched fist and sits slightly left of center in the chest.