A fist-sized pump that beats three billion times and never asks for rest
Your heart is really a double pump. The right side sends oxygen-poor blood to the lungs; the left side sends oxygen-rich blood to the body. Four chambers, four valves, one relentless rhythm. Tap any part of the model to open its story.
Blue, oxygen-poor blood returns from the body into the right atrium, drops into the right ventricle, and is pushed to the lungs to collect oxygen and dump carbon dioxide.
Fresh red blood returns from the lungs into the left atrium, fills the powerful left ventricle — the heart's strongest chamber — and is blasted out to the entire body through the aorta.
Four one-way valves (tricuspid, pulmonary, mitral, aortic) snap shut to stop backflow. That closing is the "lub-dub" you hear through a stethoscope.
The heart makes its own electricity. A patch of cells — the SA node — fires ~72 times a minute, a natural pacemaker that keeps the beat even with every nerve cut.
Blood carries oxygen and fuel to 37 trillion cells and hauls away their waste. Stop the pump and the brain fades in seconds — the whole body is built around keeping this one muscle going.
The heart beats about 100,000 times a day, every day, for a lifetime — roughly 3 billion beats — resting only in the split second between beats.
The heart has its own dedicated supply — the coronary arteries. When those clog, the muscle starves: that is a heart attack.
Each day your heart pumps around 7,500 litres of blood — enough to fill a small tanker — through some 100,000 km of vessels, more than twice around the Earth.
Across the Upaniṣads and the yogic tradition, the heart is far more than a pump — it is the dwelling of the Self. Offered here as contemplative wisdom, sitting beside, not inside, the anatomy.
In tantric yoga the Anāhata chakra sits at the centre of the chest — a twelve-petalled lotus, the meeting point of the lower and higher energies, the centre of love, compassion and balance. Anāhata means "unstruck" — the sound that sounds without two things striking, heard in deep stillness.
The Chāndogya Upaniṣad speaks of the hṛdayākāśa, the "space within the heart" — as vast within as the cosmos without, and the place where the Ātman (the Self) is said to dwell. The heart, not the head, is the traditional seat of consciousness.
The pulse and the breath were seen as the visible motion of prāṇa, the life-force. Āyurveda and yoga watched the pulse (nāḍī parīkṣā) as a window onto the whole body's balance — an old, careful clinical art.
In good faith: the Anāhata and the hṛdaya of the Upaniṣads are a spiritual and energetic centre — a map of inner experience, not of blood and muscle. The pumping heart the model shows is the anatomical organ that Harvey and others mapped by measurement. That a tradition placed the seat of love and self at the chest, where we still feel grief and joy as a physical ache, is a beautiful convergence — offered as poetry beside the biology, not as a claim that one is the other.
For 1,400 years, the West believed the liver made blood and the body burned it like fuel. The truth — that it circulates — was fought for hard.
Galen taught that blood was made in the liver and seeped through invisible pores in the heart's wall. Wrong on nearly every count — yet his authority froze medicine for over a millennium.
The Arab physician Ibn al-Nafis correctly describes pulmonary circulation — that blood must pass from the right heart through the lungs to the left — three centuries before Europe. His work went largely unread for 700 years.
By careful measurement, Harvey shows the heart pumps far too much blood for it to be constantly made and consumed — it must circulate, out through arteries and back through veins. Modern physiology is born.
Willem Einthoven builds the first practical electrocardiograph (ECG), recording the heart's own electrical signature — the tracing every hospital still watches today.
Christiaan Barnard performs the first human-to-human heart transplant. The patient lived 18 days — but the impossible had been done, and cardiac surgery was changed forever.
times your heart will beat across an average lifetime — around 100,000 beats every single day, without a day off.
The left ventricle can generate enough pressure to squirt blood several metres across a room. It is the strongest muscle you have, for its size.
Because it runs on its own electrical pacemaker, a heart can keep beating for a while even after being removed from the body, as long as it has oxygen.
The heart sits almost in the centre of the chest, only tilted slightly left. It feels left-sided because the powerful left ventricle thumps against that wall.
of blood vessels thread through your body. Laid end to end they would wrap more than twice around the Earth.
Your heart started beating about three weeks after conception — before you had a brain to know it, and it hasn't paused since.