Facts about the heart


Fun Facts About the Heart You Didn’t Know

How the heart works

The heart is part of your body’s circulatory system. It’s made up of the atria, ventricles, valves, and various arteries and veins. The main function of your heart is to keep blood that’s full of oxygen circulating throughout your body. Because your heart is crucial to your survival, it’s important to keep it healthy with a well-balanced diet and exercise, and avoid things that can damage it, like smoking.

While you’re probably familiar with a few heart-healthy tips, there are some fun facts about the heart that you may not know.

24 fun facts about the heart

  1. The average heart is the size of a fist in an adult.
  2. Your heart will beat about 115,000 times each day.
  3. Your heart pumps about 2,000 gallons of blood every day.
  4. An electrical system controls the rhythm of your heart. It’s called the cardiac conduction system.
  5. The heart can continue beating even when it’s disconnected from the body.
  6. The first open-heart surgery occurred in 1893. It was performed by Daniel Hale Williams, who was one of the few black cardiologists in the United States at the time.
  7. The first implantable pacemaker was used in 1958. Arne Larsson, who received the pacemaker, lived longer than the surgeon who implanted it. Larsson died at 86 of a disease that was unrelated to his heart.
  8. The youngest person to receive heart surgery was only a minute old. She had a heart defect that many babies don’t survive. Her surgery was successful, but she’ll eventually need a heart transplant.
  9. The earliest known case of heart disease was identified in the remains of a 3,500-year-old Egyptian mummy.
  10. The fairy fly, which is a kind of wasp, has the smallest heart of any living creature.
  11. The American pygmy shrew is the smallest mammal, but it has the fastest heartbeat at 1,200 beats per minute.
  12. Whales have the largest heart of any mammal.
  13. The giraffe has a lopsided heart, with their left ventricle being thicker than the right. This is because the left side has to get blood up the giraffe’s long neck to reach their brain.
  14. Most heart attacks happen on a Monday.
  15. Christmas day is the most common day of the year for heart attacks to happen.
  16. The human heart weighs less than 1 pound. However, a man’s heart, on average, is 2 ounces heavier than a woman’s heart.
  17. A woman’s heart beats slightly faster than a man’s heart.
  18. The beating sound of your heart is caused by the valves of the heart opening and closing.
  19. It’s possible to have a broken heart. It’s called broken heart syndrome and can have similar symptoms as a heart attack. The difference is that a heart attack is from heart disease and broken heart syndrome is caused by a rush of stress hormones from an emotional or physical stress event.
  20. Death from a broken heart, or broken heart syndrome, is possible but extremely rare.
  21. The iconic heart shape as a symbol of love is traditionally thought to come from the silphium plant, which was used as an ancient form of birth control.
  22. If you were to stretch out your blood vessel system, it would extend over 60,000 miles.
  23. Heart cells stop dividing, which means heart cancer is extremely rare.
  24. Laughing is good for your heart. It reduces stress and gives a boost to your immune system.

The takeaway

Your heart affects every part of your body. That also means that diet, lifestyle, and your emotional well-being can affect your heart. Emotional and physical health are both important for maintaining a healthy heart.

Read more: Healthy heart tips “

  • The heart is one of the most important organs in the human body, continuously pumping blood around our body through blood vessels.

  • Your heart is located in your chest and is well protected by your rib cage.

  • The study of the human heart and its various disorders is known as cardiology.

  • The heart is made up of four chambers, the left atrium, right atrium, left ventricle and right ventricle.

  • There are four valves in the human heart, they ensure that blood only goes one way, either in or out.

  • Blood that leaves the heart is carried through arteries. The main artery leaving the left ventricle is the aorta while the main artery leaving the right ventricle is the pulmonary artery.

  • Blood going towards the heart is carried through veins. Blood coming from the lungs to the left atrium is carried through the pulmonary veins while blood coming from the body to the right atrium is carried through the superior vena cava and inferior vena cava.

  • You might have felt your own heart beating, this is known as the cardiac cycle. When your heart contracts it makes the chambers smaller and pushes blood into the blood vessels. After your heart relaxes again the chambers get bigger and are filled with blood coming back into the heart.

  • Electricity going through your heart makes the muscle cells contract.

  • You might have watched television shows or movies where a patient in a hospital is attached to an electrocardiogram (ECG). You might recognize it as the machine with a line moving across a screen that occasionally spikes (or remains flat when a patient is dying). This machine can measure the electricity going through a patient’s heart. A doctor can use the information to know when a patient is having heart rhythm problems or even a heart attack.

  • Heart attacks cause scar tissue to form amongst normal heart tissue, this can lead to further heart problems or even heart failure.

We have compiled a small collection of amazing facts about the heart for you to impress your loved one with!

The heart is a truly amazing part of the human body.

Without a working heart, we would stand no chance of living.

The heart starts to beat before we are born, and will beat right up until our death.

The average heart beats 80 times a minute! This adds up to around 115,000 times a day, or 42 million times a year!

Every day the heart creates enough energy to drive a truck 20 miles.

The heart starts to beat at around four weeks after conception, and continues to do so until your death.

You’re more likely to have a heart attack on a Monday then on any other day of the week.

There’s a one in three chance that your first heart attack will be your last.

A babies heart contains the same number of cells as an adult heart but is only one-sixteenth the size!

A newborn has a much faster heartbeat, beating from 70 to 190 beats per minute.

A females heart is smaller than a males by about 25%. Because of this, the female heart has to beat around six times more than a male heart to pump the correct amount of blood around the body.

The ‘thud-thud’ a heartbeat makes is the sound made by the four valves of the heart opening and closing.

The ancient Egyptians believed that the heart, along with other major organs, had wills of their own and could move around inside the body!


Ours hearts are essential to our survival. They are part of our circulatory system and they are responsible for pumping oxygen-rich blood throughout our body, but how much do we really know about our heart?

Here are 10 interesting facts about the human heart that you may not have known:

  • The average heart is the size of an adult fist.
  • Your heart will beat about 115,000 times each day.
  • The beating sound your heart makes is caused by the opening and closing of its valves.
  • Each day, your heart pumps about 2,000 gallons of blood.
  • If you were to stretch out your blood vessel system, it would extend over 60,000 miles.
  • The human heart weighs less than one pound, but a man’s heart is typically two ounces heavier than a woman’s.
  • A woman’s heart beats slightly faster than a man’s.
  • There is such a thing as a broken heart. Symptoms are similar to a heart attack but the cause is usually stress and not heart disease.
  • Laughing is good for your heart. It reduces stress and gives a boost to your immune system.

While these facts are meant to be light and fun, the most important thing to understand is how important it is to maintain proper heart health. By eating right and exercising, you can remain heart healthy.

To speak with a doctor at Flushing Hospital about your heart health, please call 718-670-5486.

All content of this newsletter is intended for general information purposes only and is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. Please consult a medical professional before adopting any of the suggestions on this page. You must never disregard professional medical advice or delay seeking medical treatment based upon any content of this newsletter. PROMPTLY CONSULT YOUR PHYSICIAN OR CALL 911 IF YOU BELIEVE YOU HAVE A MEDICAL EMERGENCY.

Matters of the Heart

(Image credit: Credit: Dreamstime)

Matters of the heart have baffled humans since the dawn of time, with sonnets and entire books devoted to the meaning of love. Now scientists are finding that the blood pump in your chest is just as complex. You can’t live or love without it. Find out the sappy scoop on the heart, including how sex and laughter are indeed good for it, and how bad news really can break it.

Love Sign

(Image credit: Dreamstime)

Weighing in at 10 ounces, the blood-filled muscle called the heart has become the universal symbol of love. The Greeks believed the heart was the seat of the spirit, the Chinese associated it with the center for happiness and the Egyptians thought the emotions and intellect arose from the heart. No one is sure the exact origin of the love association, however. One idea is that the heart got its “love mark” in the ancient Greek city of Cyrene, now in modern-day Libya. The colony was known for a plant called Silphium, with heart-shaped seed pods. Silphium had medicinal properties, and possibly also was used as an herbal contraceptive.

Broken Heart

(Image credit: Dreamstime)

Alas, a broken heart can cause one to swoon. A breakup with a loved one or news of a family death literally can lead to broken hearts in the form of heightened risk for heart attack, studies have shown. Such trauma can also trigger the release of stress hormones into the bloodstream that temporarily “stun” the heart. The resulting symptoms mimic those of a heart attack – chest pain and shortness of breath – but this type of achy heart can bounce back in days with some TLC and rest.

Powerful Pump

In under a minute, your heart can pump blood to every cell in your body. And over the course of a day, about 100,000 heart beats shuttle 2,000 gallons of oxygen-rich blood many times through about 60,000 miles of branching blood vessels that link together the cells of our organs and body parts. That’s a hefty job for a fist-sized muscle.

Drink to Your Heart

(Image credit: Dreamstime)

A glass of Merlot can go straight to the heart, and recent research shows that so too can the white variety. Scientists have attributed the heart benefits of reds to grape skins, which are chock full of certain antioxidants. Since the purple-hued skins get removed to make Chardonnays, many scientists had assumed white wine likely wouldn’t do the heart any good. A lab experiment on rats showed that a grape’s pulp conceals cardio-protective compounds that rival those found in reds. Red or white? Just follow your heart.

LOL: It’s Good for You

(Image credit: dreamstime)

A hearty laugh – the kind that sends a stream of tears from your eyes – does more than warm the soul. Research has shown the guffaw can cause the lining of blood vessel walls called endothelium to relax, increasing blood flow for up to 45 minutes after the laugh attack. Damage to the endothelium can lead to the narrowing of blood vessels and eventually cardiovascular diseases. That’s no laughing matter … or maybe it is…

Big Hearts

(Image credit: © Dawn Hudson | Dreamstime.com)

Some people really do have bigger hearts than others. Rather than a sign of affection, an enlarged heart can signal underlying heart disease. The most common type, called dilated cardiomyopathy, occurs when the heart’s chambers stretch out and enlarge. The bulging saps the heart’s pump power, depriving the body’s organs of enough blood. If left untreated, a big heart can lead to heart failure.


(Image credit: Mark Philbrick | BYU)

A seemingly sheepish look from Fido or that endearing brush-by from your cat can make you wonder if your pet could possibly communicate with you. A recent study adds equine friends to the list of emotionally-responsive animals. A scientist found that horse’s heart rates mirror those of human subjects touching them. The horse emotion-detector could someday replace procedures used to measure a patient’s stress hormones. Next, the researcher will study service dogs to better match them with humans.

Heart Mend

A love-torn heart can be painful enough to make you wish you could get a new heart or at least a cardio repair kit. Both of the latter options could some day be realities. Scientists are studying the red-spotted newt to help them develop cell therapies for humans with physically damaged hearts. This amphibian can turn its cells back in time, as if they were stem cells, in order to build up new heart muscle. In another study, scientists engineered a beating heart from embryonic stem cells in the lab.

Female Hearts

(Image credit: Credit: Alane Basco-Yu)

Girls rule in some matters of the heart, but when it comes to research into cardiovascular disease it’s the guys who come into the spotlight. For decades, heart disease and heart attacks have been viewed as a man’s illness. But this is far from the truth. Heart disease kills 500,000 American women each year, topping male numbers by 50,000. Another gender gap: Women don’t tend to experience the Hollywood-standard heart attack in which gripping chest pain sends you keeling over. Instead, women have reported tightness, aching or pressure in the heart, plus other symptoms like nausea, back and jaw pain.

Sex Appeal

(Image credit: Credit: Dreamstime)

If you can’t make it to the gym, try fooling around. Your heart might thank you. A study of 2,500 men aged 49 to 54 found that having an orgasm at least three times a week cut in half the likelihood of death from coronary heart disease. And barring underlying health issues and the possibility of contracting a sexually transmitted disease, sex can give you a workout. By some estimates, a vigorous sex session can double a person’s heart rate and burn up about 200 calories, or the equivalent of a brisk 15-minute run. So staying in bed might be just what the doctor orders.

February is the month dedicated to hearts… and no, we don’t just mean the ones on your Valentine’s Day card!

It’s also National Heart Month, a time dedicated to spreading education, awareness, and even some fun facts. Here are 15 interesting bits of information you may not know about your body’s hardest working muscle.

1) Positivity is Good for Your Heart

Feeling a strong sense of emotional vitality and overall happiness has been shown to decrease your risk of heart disease.

2) A Lifetime Worth 2.5 Billion Heart Beats

According to the American Heart Association, an adult heart beats approximately 100,000 times per day. That’s about 60 to 100 beats per minute, or at least one beat per second. In an average lifetime, a human heart will beat over 2.5 billion times.

3) Early Pacemakers Had Plugs

The first pacemakers plugged into a wall socket! Of course, they’ve come a long way since then…

4) Fitness Can Help Slow Your Heart Rate

Heart rate is affected by age and fitness level. Typically the heart rate slows as children get older or adults get fitter. This chart from the National Institutes of Health can give you an idea of how time affects those cardiovascular changes:

  • Newborn: 70 to 160 bpm
  • One to four years: 80 to 120 bpm
  • Five to nine years: 75 to 110 bpm
  • Children 10+ years and non-athletic adults: 60 to 100 bpm
  • Athletic adults: 40 to 60 bpm

5) Modesty Led to the Creation of the Stethoscope

The invention of the stethoscope was prompted by modesty. Before physicians had stethoscopes, they had to put their ear directly on the patient’s chest.

6) Your Heart is Actually a Handful

An adult heart is about the size of that person’s hands clasped together in a double first. Since people vary in size, your most realistic assessment is made using your own hands. However, a heart can also enlarge because of certain illness and conditions, such as congestive heart failure.

7) That First Beat is at Four Weeks

The heart begins beating at four weeks after conception.

8) Heart Attack Symptoms Differ Based on Your Sex

Men and women typically experience different heart attack symptoms.

Men usually report:

  • Sweating
  • Crushing chest pain
  • Nausea

Women often report:

  • Shortness of breath
  • Fainting or lightheadedness
  • Dizziness
  • Pain in the lower chest
  • Pain in the upper abdomen
  • Upper back pressure

9) The True Source of That Heart Beat Sound

A normal heart valve is about the size of a half dollar. The beating sound your heart makes is a result of its four valve leaflets closing.

10) Heart Disease is an Equal Opportunity Killer

Though we often talk about heart disease being our country’s number one killer of men, it’s also the leading killer of women. According to James Beckerman, MD, director of the Center for Prevention and Wellness at the Providence Heart and Vascular Institute in Portland, “Heart disease is an equal opportunity buzz kill.” In fact, more women pass due to heart disease than most cancers combined. Over one in three women is living with heart disease, and every minute one American woman dies from:

  • Heart disease
  • Stroke
  • Other cardiovascular disease

11) Enough Blood to Fill a Truck

Each minute, your heart pumps an impressive 1.5 gallons of blood. Over the average lifetime, it will pump enough blood to fill more than three super tanker trucks.

12) Depression is Hard on the Heart

Depression increases heart attack risk, especially in women. If you’re a woman under 55 with moderate or severe depression, you are over twice as likely to:

  • Require an artery-opening procedure
  • Suffer a heart attack
  • Die of heart disease

13) Your Heart Supports Trillions

Your body has about 75 trillion cells, and your heart pumps blood to almost all of them. Just your corneas don’t receive blood!

14) All You Need is a Little O2

The heart has its own electrical impulse and can continue to beat when separated from the body– as long as it’s receiving oxygen!

15) Stay Active for Your Heart

The last (and arguably most important!) fact for the day is that YOU are in control of the greatest potential risk factor for heart disease. That risk factor is your activity level! The American Heart Association recommends getting at least a weekly 150 minutes of moderate-intensity exercise, or 75 minutes of vigorous exercise, or a combination of the two. Other ways to lower your risk include:

  • Quitting smoking
  • Eating better
  • Controlling cholesterol
  • Reducing blood sugar
  • Managing blood pressure
  • Losing weight

Your heart is your hardest-working muscle! It only catches a break when you’re resting or sleeping, and even then it’s still ticking. Educating yourself on heart health is a crucial part of your overall wellness. You already took an excellent first step by reading this article. We recommend keeping the proactivity flowing with healthy food and physical activity this month–and beyond!

The heart. Undeniably the most important organ in the human body, but what do you know and what don’t you know about the beating muscle that keeps working even when we’re resting?

Here’s our top 50 facts about the heart that you don’t know… probably.

  1. Of all the hearts in the world, the Blue Whale’s is the largest – weighing in at 1,500 pounds
  2. Your heart is about the size of your two hands clasped together
  3. If you’re a child, your heart is about the same size as your fist
  4. Your heart beats 100,000 times a day
  5. Regular exercise is the single most important key to heart health
  6. Heart disease is your single greatest health threat
  7. The ‘thump-thump’ of a heart beat is the sound made by the four valves of the heart closing
  8. Each minute your heart pumps 1.5 gallons of blood around the body
  9. The right side of the heart pumps blood into your lungs, the left side pumps it back into your body
  10. Heart cancer is very rare, because heart cells stop dividing early in life
  11. A woman’s average heartbeat is faster than a man’s by almost 8 beats a minute
  12. Your heart pumps about 1 million barrels of blood during an average lifetime – enough to fill more than 3 super tankers
  13. A kitchen faucet would need to be turned on all the way for at least 45 years to equal the amount of blood pumped by the heart in an average lifetime
  14. Because the heart has its own electrical impulse, it can continue to beat even when separated from the body – as long as it has an adequate supply of oxygen
  15. The heart begins beating at four weeks after conception
  16. The heart of an average man beats approximately 70 times a minute
  17. The heart of an average woman beats approximately 78 times a minute
  18. 75 trillion cells in the body receive blood from the heart – only the corneas don’t
  19. Research has indicated that owning a cat can reduce the risk of heart attacks and strokes by more than a third
  20. Your heartbeat changes and mimics the music you listen to
  21. Your left lung is smaller than your right lung to make room for your heart
  22. Vegetarians are 19% less likely to die from heart disease, a study found
  23. Eating dark chocolate every day reduces the risk of heart disease by one-third
  24. The human heart is not on the left hand side of the body, it’s in the middle
  25. The heart has the ability to beat over 3 billion times in a person’s lifetime
  26. The heart pumps out 2 ounces of blood at every heartbeat
  27. Heart break can be literal, in a recent study of nearly 2000 heart attack survivors – attacks were far more likely to happen soon after the death of a family member or close friend than other times
  28. Coffee drinkers are less likely to be hospitalized or worried about heart rhythm disturbances, even though the caffeine in coffee can make the heart beat faster
  29. A sneeze stops the heart? Simple a myth!
  30. The fetal heart is approximately twice as fast as an adult’s, at about 150 beats per minute, by the time a fetus is 12 weeks old, it’s heart pumps an amazing 60 pints of blood a day
  31. Approximately 5% of blood supplies the heart, 15-20% goes to the brain and central nervous system, and 22% goes to the kidneys
  32. Early Egyptians believed that the heart and other major organs had wills of their own and would move around inside the body
  33. Plato theorised that reasoning originated with the brain, but that passions originated in the ‘fiery’ heart
  34. The term ‘heartfelt’ originated from Aristotle’s philosophy that the heart collected sensory input from the peripheral organs through the blood vessels
  35. Prolonged lack of sleep can cause irregular jumping heartbeats also known as Premature Ventricular Contractions (PVCs)
  36. Some heavy snorers may have a condition called Obtrusive Sleep Apnea (OSA) which can negatively affect the heart
  37. Drug use, particularly cocaine, affects the heart’s electrical activity and causes spasm of the arteries, which can lead to a heart attack or stroke, even in healthy people
  38. Galen of Pergamum, who was a prominent surgeon to Roman gladiators, demonstrated that blood, not air, filled arteries – as Hippocrates had concluded, way back when
  39. ‘Atrium’ is latin for ‘entrance hall’ and ‘ventricle’ is latin for ‘little belly’
  40. Physician Erasistratus of Chios (304-250 B.C.) was the first person to discover that the heart functioned as a natural pump
  41. Grab a tennis ball and squeeze it tightly, that’s how hard the beating heart works to pump blood around the body
  42. In 1903, physiologist Willem Einthoven (1860-1927) invented the electrocardiograph, which measures the electric current which flows through the heart
  43. The walls of the heart’s left atrium are three times thicker than the right atrium
  44. The human heart is not ‘heart shaped’, in fact a cow’s heart is closer to the heart shape we use to indicate the heart
  45. A normal heart valve is about the same size of a 50cent piece
  46. The first heart pacemakers plugged into a wall socket, you couldn’t go very far!
  47. Every day, your heart creates enough energy to drive a truck for 20 miles (32KM for our American friends)
  48. Worldwide, 17.3 million people die each year from heart disease or stroke, which accounts for 31% of all deaths
  49. When the body is resting, it takes just 6 seconds for blood to travel from the heart to the lungs and back – and only 8 seconds for it to go to the brain and back
  50. Happiness and a strong sense of emotional vitality helps lower your risk of heart disease

If you would like to learn more about the heart, cardiac arrest, defibrillators and everything in between, our FAQ page is packed full of useful information whilst our friendly and impartial defibshop team are always on hand to help.

You can contact the team on 0845 071 0830 or alternatively you can fill out one of our contact forms and a member of the team will get back to you as soon as possible.

9 Unusual Facts About Your Heart

Your heart is a wondrous organ, beating around 100,000 times a day and filling your body with oxygen-rich blood. We all know it is approximately the size of a fist, and women’s hearts beat faster than men’s, but here are some more unusual facts about your heart and the things it can do.

It can beat when separated from the body.

Since the heart has its own electrical impulse, it is not regulated by the brain, but within the heart itself. Therefore, it can beat even when it’s separated from the body as long as it has an adequate oxygen supply.

Heart attacks peak around Christmas.

Oddly enough, the most wonderful time of the year is also the most common time of the year for heart attacks. Many factors contribute to this unfortunate truth, so take care of yourself during all the holiday preparations.

Heart cancer is rare.

Because heart cells stop dividing early in life, cancer-causing mutations are rare. Other cancers, however, can spread to your heart and chemotherapy can damage its tissue.

The only body part that doesn’t receive blood is the corneas.

Most tissues in the body contain blood vessels to receive nourishment and protect against infection, but the corneas are the only body part that lack blood vessels and therefore do not receive blood. Blood vessels in the corneas would compromise its transparency so they are nourished in other ways, such as from tear fluid.

Blood is actually a tissue.

It is thick because it’s made up of cells, and is roughly 80% water and 20% solid. It also contains hormones, fats, carbohydrates, proteins and gases.

Going up a shoe size could indicate a heart problem.

If your heart is not pumping correctly, your body will retain water. This causes swelling in the legs and feet, which can make your shoes not fit correctly. If you notice swelling and you need larger shoes, it’s a good idea to check in with your doctor.

Sneezing doesn’t stop your heart.

This is an old myth. When you sneeze, the blood flow back to the heart decreases. The heart rhythm adjusts to accommodate this, but the heart itself does not actually stop.

A bigger heart can indicate a problem.

Some people have bigger hearts than others — and physically speaking, this is not a good thing. This can indicate heart disease or high blood pressure, both of which can lead to heart failure, abnormal heart rhythm or other issues.

Your heartbeat changes based on music you’re listening to.

Have you noticed if you are stressed, music can calm you down? Studies have shown that listening to fast-paced music can increase your heart rate, while slow-paced music decreases it.

So there you have it — some unusual heart facts that prove your heart can do amazing things and keep you alive! Be sure to take care of your ticker for a long life. If you or a loved one think they may be experiencing heart issues, contact us today at the Fisher-Titus Snyder/White Heart & Vascular Center by calling 419-660-6946.

The human heart is an organ that pumps blood throughout the body via the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes.

“The tissues of the body need a constant supply of nutrition in order to be active,” said Dr. Lawrence Phillips, a cardiologist at NYU Langone Medical Center in New York. “If is not able to supply blood to the organs and tissues, they’ll die.”

Human heart anatomy

In humans, the heart is roughly the size of a large fist and weighs between about 10 to 12 ounces (280 to 340 grams) in men and 8 to 10 ounces (230 to 280 grams) in women, according to Henry Gray’s “Anatomy of the Human Body.”

The physiology of the heart basically comes down to “structure, electricity and plumbing,” Phillips told Live Science.

The human heart is about the size of a fist. (Image credit: tlorna )

The human heart has four chambers: two upper chambers (the atria) and two lower ones (the ventricles), according to the National Institutes of Health. The right atrium and right ventricle together make up the “right heart,” and the left atrium and left ventricle make up the “left heart.” A wall of muscle called the septum separates the two sides of the heart.

A double-walled sac called the pericardium encases the heart, which serves to protect the heart and anchor it inside the chest. Between the outer layer, the parietal pericardium, and the inner layer, the serous pericardium, runs pericardial fluid, which lubricates the heart during contractions and movements of the lungs and diaphragm.

The heart’s outer wall consists of three layers. The outermost wall layer, or epicardium, is the inner wall of the pericardium. The middle layer, or myocardium, contains the muscle that contracts. The inner layer, or endocardium, is the lining that contacts the blood.

The tricuspid valve and the mitral valve make up the atrioventricular (AV) valves, which connect the atria and the ventricles. The pulmonary semi-lunar valve separates the right ventricle from the pulmonary artery, and the aortic valve separates the left ventricle from the aorta. The heartstrings, or chordae tendinae, anchor the valves to heart muscles.

The sinoatrial node produces the electrical pulses that drive heart contractions.

Human heart function

The heart circulates blood through two pathways: the pulmonary circuit and the systemic circuit.

In the pulmonary circuit, deoxygenated blood leaves the right ventricle of the heart via the pulmonary artery and travels to the lungs, then returns as oxygenated blood to the left atrium of the heart via the pulmonary vein.

In the systemic circuit, oxygenated blood leaves the body via the left ventricle to the aorta, and from there enters the arteries and capillaries where it supplies the body’s tissues with oxygen. Deoxygenated blood returns via veins to the venae cavae, re-entering the heart’s right atrium.

Of course, the heart is also a muscle, so it needs a fresh supply of oxygen and nutrients, too, Phillips said.

The cardiovascular system circulates blood from the heart to the lungs and around the body via blood vessels. (Image credit: The BioDigital HumanTM developed by NYU School of Medicine and BioDigital Systems LLC)

“After the blood leaves the heart through the aortic valve, two sets of arteries bring oxygenated blood to feed the heart muscle,” he said. The left main coronary artery, on one side of the aorta, branches into the left anterior descending artery and the left circumflex artery. The right coronary artery branches out on the right side of the aorta.

Blockage of any of these arteries can cause a heart attack, or damage to the muscle of the heart, Phillips said. A heart attack is distinct from cardiac arrest, which is a sudden loss of heart function that usually occurs as a result of electrical disturbances of the heart rhythm. A heart attack can lead to cardiac arrest, but the latter can also be caused by other problems, he said.

The heart contains electrical “pacemaker” cells, which cause it to contract — producing a heartbeat.

“Each cell has the ability to be the ‘band leader’ and have everyone follow,” Phillips said. In people with an irregular heartbeat, or atrial fibrillation, every cell tries to be the band leader, he said, which causes them to beat out of sync with one another.

A healthy heart contraction happens in five stages. In the first stage (early diastole), the heart is relaxed. Then the atrium contracts (atrial systole) to push blood into the ventricle. Next, the ventricles start contracting without changing volume. Then the ventricles continue contracting while empty. Finally, the ventricles stop contracting and relax. Then the cycle repeats.

Valves prevent backflow, keeping the blood flowing in one direction through the heart.

Facts about the human heart

  • A human heart is roughly the size of a large fist.
  • The heart weighs between about 10 to 12 ounces (280 to 340 grams) in men and 8 to 10 ounces (230 to 280 grams) in women.
  • The heart beats about 100,000 times per day (about 3 billion beats in a lifetime).
  • An adult heart beats about 60 to 80 times per minute.
  • Newborns’ hearts beat faster than adult hearts, about 70 to 190 beats per minute.
  • The heart pumps about 6 quarts (5.7 liters) of blood throughout the body.
  • The heart is located in the center of the chest, usually pointing slightly left.

Editor’s Note: If you’d like more information on this topic, we recommend the following book:

  • Human Body: Anatomy, Facts & Functions

Systems of the human body

  • Circulatory System: Facts, Function & Diseases
  • Digestive System: Facts, Function & Diseases
  • Endocrine System: Facts, Functions and Diseases
  • Immune System: Diseases, Disorders & Function
  • Lymphatic System: Facts, Functions & Diseases
  • Muscular System: Facts, Functions & Diseases
  • Nervous System: Facts, Function & Diseases
  • Reproductive System: Facts, Functions and Diseases
  • Respiratory System: Facts, Function & Diseases
  • Skeletal System: Facts, Function & Diseases
  • Skin: Facts, Diseases & Conditions
  • Urinary System: Facts, Functions & Diseases

Parts of the human body

  • Bladder: Facts, Function & Disease
  • Human Brain: Facts, Anatomy & Mapping Project
  • Colon (Large Intestine): Facts, Function & Diseases
  • Ears: Facts, Function & Disease
  • Esophagus: Facts, Function & Diseases
  • How the Human Eye Works
  • Gallbladder: Function, Problems & Healthy Diet
  • Kidneys: Facts, Function & Diseases
  • Liver: Function, Failure & Disease
  • Lungs: Facts, Function & Diseases
  • Nose: Facts, Function & Diseases
  • Pancreas: Function, Location & Diseases
  • Small Intestine: Function, Length & Problems
  • Spleen: Function, Location & Problems
  • Stomach: Facts, Function & Diseases
  • The Tongue: Facts, Function & Diseases

Additional resources

  • The National Institutes of Health has information about heart and vascular diseases.
  • The American Heart Association has tips about how to keep your heart healthy.

Follow Tanya Lewis on Twitter. Follow us @livescience, Facebook & Google+.

10 Amazing Facts About Your Heart

Your heart isn’t only your most critical muscle — it’s what keeps you alive, after all — but also one of the hardest working. It ticks 24-7 and except for the times when you’re relaxing or sleeping, it rarely gets a break. Below, find fascinating facts about your heart that might inspire you to give it a little more TLC every day.

1. Your adult heart beats about 100,000 times each day. Do the math, and that’s at least one beat every second, or 60 to 100 times a minute, according to the American Heart Association. For people whose heart rate is closer to 60 beats per minute (bpm), that’s about 86,000 times a day. And it’s 144,000 times a day if your heart rate is closer to 100 bpm.

2. Age and fitness level affect your heart rate. Generally, as children grow or adults get fitter, the heart rate gets slower. See how it changes throughout the decades with this chart from the National Institutes of Health:

  • Newborn (0 to 11 months): 70 to 160 bpm
  • One to four years: 80 to 120 bpm
  • Five to nine years: 75 to 110 bpm
  • Children 10 years and up and adults (non-athletes): 60 to 100 bpm
  • Adults (athletes): 40 to 60 bpm

3. Heart disease isn’t only the number one killer of men, it’s also the top killer for women. Your heart doesn’t care if you’re from Mars or Venus. “Heart disease is an equal opportunity buzz kill,” says James Beckerman, MD, director of the Center for Prevention and Wellness at the Providence Heart and Vascular Institute in Portland, Oregon, and author of Heart to Start (2015). More women die of heart disease than from most cancers combined, notes Dr. Beckerman.

According to the American Heart Association (AHA), more than one in three women is living with heart disease. Every minute in this country, one woman dies from heart disease, stroke, or another form of cardiovascular disease.

4. Want to know how big your heart is? Make a fist. Heart size depends on the size of the person as well as the condition of their heart. Generally speaking, a healthy heart is about the size of the person’s fist.

That’s only a healthy heart, though. “Hearts can enlarge in response to certain conditions,” says Kathryn Boling, MD, a family medicine physician with Lutherville Personal Physicians in Lutherville, Maryland. For instance, congestive heart failure can cause the heart to enlarge, explains the American College of Cardiology.

5. Your heart rate drops while you sleep. At night, it’s common for heart rates to drop below 60 bpm. Some people even have rates in the 40s while sleeping. Why? “It’s because your metabolism slows and the parasympathetic nervous system, which slows your heart and relaxes you, is more active,” Boling says.

6. Heart attack symptoms are different in men and women. Although heart disease is an equal opportunity killer, symptoms of heart attack show up differently in men versus women. Whereas men often report crushing chest pain, sweating and nausea, women might instead experience shortness of breath, dizziness, lightheadedness or fainting, pain in the lower chest or upper abdomen,a nd upper back pressure, notes the AHA.

7. Your activity level is the greatest potential risk factor for heart disease. People with low fitness levels have double the risk of heart disease as their more active counterparts, Beckerman says. The AHA recommends logging at least 150 minutes of moderate-intensity exercise, or 75 minutes of vigorous activity, or a combination of the two, every week.

RELATED: 6 Heart-Health Benefits of Yoga

The good news is, “whether you’re on the treadmill, in the weight room, or in a yoga studio, your heart benefits from every type of activity,” he says. And 80 percent of heart disease is preventable with healthy lifestyle choices and management of risk factors, he adds. Other ways to lower heart disease risk include quitting smoking, controlling cholesterol, eating better, managing blood pressure, losing weight, and reducing blood sugar, according to the AHA.

8. Depression increases your risk for a heart attack, especially if you’re a woman. If you’re a woman under 55 with moderate or severe depression, listen up. This group of women are more than twice as likely to suffer a heart attack, die of heart disease, or require an artery-opening procedure, Boling says.

9. Excessive amounts of sitting have been linked to an increased risk of heart disease. You may have heard that sitting is the new smoking. Numerous studies show that spending most of the day on your duff has been linked to chronic health conditions, including heart disease.

“When we’re more active, even with smaller movements like when we stand or shift from side to side, our muscles turn on genes that create chemicals and proteins that not only help us process blood sugar and cholesterol more efficiently but also create a healthier atmosphere in the walls of our blood vessels,” Beckerman says. That then leads to a lower heart disease risk, which is why you should stand up and move around at least every hour for a few minutes.

10. Your heart is one giant pump. Every minute, your heart pumps about five quarts of blood through a system of blood vessels that’s over 60,000 miles long, according to the Cleveland Clinic. That translates to about 2,000 gallons of blood every day.

The heart: All you need to know

The heart contracts at different rates depending on many factors. At rest, it might beat around 60 times a minute, but it can increase to 100 beats a minute or more. Exercise, emotions, fever, diseases, and some medications can influence heart rate. For more information on what is “normal,” read this article.

The left and right side of the heart work in unison. The right side of the heart receives deoxygenated blood and sends it to the lungs; the left side of the heart receives blood from the lungs and pumps it to the rest of the body.

The atria and ventricles contract and relax in turn, producing a rhythmical heartbeat:

Right side

  • The right atrium receives deoxygenated blood from the body through veins called the superior and inferior vena cava (the largest veins in the body).
  • The right atrium contracts and blood passes to the right ventricle.
  • Once the right ventricle is full, it contracts and pumps the blood through to the lungs via the pulmonary artery, where it picks up oxygen and offloads carbon dioxide.

Left side

  • Newly oxygenated blood returns to the left atrium via the pulmonary vein.
  • The left atrium contracts, pushing blood into the left ventricle.
  • Once the left ventricle is full, it contracts and pushes the blood back out to the body via the aorta.

Each heartbeat can be split into two parts:

Diastole: the atria and ventricles relax and fill with blood.

Systole: the atria contract (atrial systole) and push blood into the ventricles; then, as the atria start to relax, the ventricles contract (ventricular systole) and pump blood out of the heart.

When blood is sent through the pulmonary artery to the lungs, it travels through tiny capillaries on the surface of the lung’s alveoli (air sacs). Oxygen travels into the capillaries, and carbon dioxide travels from the capillaries into the air sacs, where it is breathed out into the atmosphere.

The muscles of the heart need to receive oxygenated blood, too. They are fed by the coronary arteries on the surface of the heart.

Where blood passes near to the surface of the body, such as at the wrist or neck, it is possible to feel your pulse; this is the rush of blood as it is pumped through the body by the heart. If you would like to take your own pulse, this article explains how.

5 Things Your Heart Wants You to Know

Sure, you may hear a lot about heart health, but what does keeping your heart healthy really mean? In short, it means eating right, getting physical activity and knowing your risks for heart disease.

Get the Facts

Here are five facts your heart would tell you about staying healthy…if it could.

1. Heart disease is the leading cause of death for both men and women in the U.S.

Most people fear cancer or diabetes. These are serious illnesses, but it’s heart disease that kills more people year after year.

Good news—you can take action to reduce your risk of heart disease.

2. Heart disease is not just for old people.

Although aging increases our risk for heart disease, it’s a myth that young people are not impacted by this condition.

When you have your annual exam, talk to your doctor about your risk for heart disease and how you can work with him or her to monitor it.

3. Certain foods promote heart health.

You probably already know that eating more fruits and vegetables is good for your heart health. But, did you know that salmon, nuts and dark chocolate can also help reduce your risk of heart disease?

By incorporating a variety of heart healthy foods in your meals, you create a heart-healthy diet.

4. High blood pressure makes your heart work harder.

If plaque collects in your arteries, then your heart has to pump harder to move blood throughout your body. This extra effort causes high blood pressure and puts stress on your heart.

Help your heart by eating low cholesterol foods, such as fruits, vegetables and multi-grain items. Foods lower in cholesterol reduce your risk of high blood pressure and heart disease because they don’t create plaque in your arteries.

Know your numbers. Check your blood pressure regularly. Talk to your primary care doctor to get checked.

5. Quit smoking and your heart will thank you

Of course, your lungs are grateful if you stop smoking, but your heart is grateful too. Smoking is a risk factor for heart disease and quitting will help reduce your risk.

Show your heart some love. Schedule a heart health screening today.

About the author

Leave a Reply

Your email address will not be published. Required fields are marked *