Cardiovascular system
Heart
The heart is a muscular pump about the size of a fist that pushes blood around the body. It beats around 100,000 times a day, delivering oxygen and nutrients to every cell.
What it is
The heart is a hollow, muscular organ with four chambers — two upper (atria) and two lower (ventricles). It sits between the lungs and is the engine of the circulatory system.
Where it is
In the chest, slightly left of centre, between the two lungs and behind the breastbone.
What it does
Pumps blood continuously around the body: sending oxygen-poor blood to the lungs to collect oxygen, and pumping oxygen-rich blood out to supply every organ and tissue.
How it works
The heart works as two pumps side by side. The right side receives blood returning from the body and sends it to the lungs to pick up oxygen; the left side receives the oxygen-rich blood and pumps it out to the body. Four valves keep blood flowing one way, and the heart's own electrical system sets the rhythm of the heartbeat.
When things go wrong
Common conditions affecting the heart
- Coronary heart disease and heart attack
- Heart failure
- Abnormal heart rhythms (arrhythmias) such as atrial fibrillation
- Heart valve problems
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. Sudden severe symptoms — such as severe chest pain, breathlessness or collapse — are an emergency; call 999.
Looking after it
Keeping your heart healthy
Not smoking, staying active, eating a heart-healthy diet, keeping blood pressure and cholesterol in check, and limiting alcohol all protect the heart.
Did you know?
An interesting fact
The heart beats around 100,000 times a day and pumps roughly 7,000 litres of blood — enough to fill a small swimming pool over a few days.
Answers
Heart: frequently asked questions
What does the heart do?
The heart is a muscular pump that pushes blood around the body, delivering oxygen and nutrients and carrying away waste.
What are the warning signs of a heart attack?
Central chest pain or pressure that may spread to the arm, jaw or back, often with sweating, breathlessness or nausea. It is a medical emergency — call 999 immediately.
Sources
Where this is drawn from
- NHS — Anatomy and body systems
- Gray's Anatomy for Students
- TeachMeAnatomy / TeachMePhysiology
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