It’s the week of hearts and flowers, so how about putting the spotlight on the human heart?

A kind person is sometimes described as“having a heart as big as all outdoors.” In reality? The average heart is about the size of an adult fist and weighs somewhere between 7 and 15 ounces (200 to 425 grams), less than 0.5% of a person’s total body weight.    The male heart typically weighs about 2 ounces (57 grams) more than a female one.

      The heart sits between the lungs at the front of the chest, slightly behind and to the left of the breastbone. In order to make room for the heart, the left lung is a little smaller than the right lung. The body’s ribs provide extra protection for the organ.

The heart is divided into two parts, separated by a wall of muscles known as a septum. Each part holds an atrium and a ventricle. The atria, from the Latin word for “entrance hall,” are the two upper chambers, while the ventricles, translating “little belly,” are toward the bottom of the heart. Blood inside the heart flows in only one direction, with four one-way valves to prevent blood from flowing backward. Blood enters the heart through the right atrium, then moves to the right ventricle. Blood is then pumped to the lungs where it picks up oxygen, then moves to the left atrium, to the left ventricle, exiting there to supply the body.

The ventricles have thicker walls than the atria, generating higher blood pressure. In fact, the blood pressure in the left ventricle is high enough to squirt blood to a height of 30 feet!

    The “thump-thump” sound of a heartbeat is from the four valves of the heart opening and closing. Each heartbeat fills all four chambers with a fresh round of blood. All the body’s blood travels through the heart once a minute.

An adult body weighing 150 to 180 lbs. will contain between 1.2 and 1.5 gallons (4.7 and 5.5 liters) of blood. Nearly all the body’s 75 trillion cells receive blood. The only exceptions are the eyes’ corneas.

    Normal hearts beats upwards of 100,000 times a day. With each beat, the heart pumps about 4 tablespoons of blood, enough to fill an Olympic-sized swimming pool in less than a year. About 2,000 gallons of blood are pumped through 60,000 miles of blood vessels every day.    Turn on your kitchen faucet full blast and leave it on for 45 years, and the amount of water would equal the amount of blood pumped by the heart over an average lifetime.

    A woman’s heart beats slightly faster than a man’s, with the average woman’s heart rate at 78 beats per minute, and the man’s at 70 bpm.

•    The human heart begins beating four weeks    after conception. By the time a baby has been delivered, his/her heart has already beat about 50 million times.   

Do you know the difference between a heart attack and cardiac arrest? A heart attack occurs when blood flow to the heart is blocked, usually because of coronary artery disease. A cardiac arrest takes place when the heart’s rhythm and electrical system malfunction and the heart stops beating.    Every year, more than two million people have open-heart surgery to correct various heart conditions.