The human heart is truly a marvel, tirelessly pumping blood day and night, year after year, for an average of 80-90 years. This remarkable muscle is the source of life and vitality, and for centuries, it has been associated with the soul due to its unwavering rhythm and life-sustaining power. To commemorate Valentine's Day, let's delve into some fascinating facts about the human heart.
1. The Mighty Human Heart Pumps Blood with Precision
Every beat of the human heart sends out a surge of blood to all parts of the body, ensuring that vital organs receive the oxygen and nutrients they need to function properly. With an average resting heart rate of 60 to 100 beats per minute, the human heart can pump up to 5 liters of blood every minute. That's a lot of blood! Elite athletes have been known to have a much higher cardiac output, pushing up to 35 liters of blood during a 100-meter dash. The amount of blood pumped per beat is determined by multiplying the number of beats per minute and the volume of blood pumped per beat, making the human heart a truly remarkable organ.
2. A Timeless Link Between Heart and Soul
Throughout history, the heart has been viewed as the center of the human body and the dwelling place of the soul. In ancient Egypt, the heart was deemed so important that it was the only organ left in place during the mummification process. The Greek physician Galen believed that the heart was the source of life and warmth, while in Norse culture, the size and temperature of one's heart were thought to determine their bravery. Despite William Harvey's discovery of the heart's true role in circulation in 1628, the connection between the heart and soul continues to be held close to many hearts today.
3. The Landmark Moment of the First Successful Human Heart Transplant
The idea of heart transplantation was explored by surgeons on animals in the early 20th century, but it was not until 1964 when the first human heart transplant took place. Unfortunately, the recipient, a critically ill man, did not survive long with a chimpanzee heart as a replacement. However, three years later, history was made at a South African hospital when Dr. Christaan Barnard and his team performed the first successful human-to-human heart transplant. The news quickly spread globally, with Barnard gracing the covers of prominent magazines such as TIME, LIFE, and Newsweek, as the world closely followed the recovery of patient Louis Washkansk. Sadly, Washkansk passed away after 18 days, but the historic procedure will always be remembered as "one of the most famous events of the 20th century" and "the most publicized event in world medical history.
4. The Human Heart Operates on Electrical Signals
The heart's electrical system, comprised of specialized cells, controls the timing and speed of heartbeats. The sinoatrial (SA) node initiates the process with an electrical impulse that spreads throughout the atria, causing them to contract and push blood into the ventricles. Another group of pacemaker cells in the atrioventricular (AV) node then signals the ventricles to contract, propelling the blood through the body. This cycle is repeated as the SA node emits fresh electrical signals
5. The Heart Rate Does Not Determine the Gender of an Unborn Fetus
The heart is the first organ to start developing in a human fetus. During the earliest stage of pregnancy, the heart starts beating in its basic form, known as the tubular heart, approximately three weeks after conception. However, a recent study suggests that this process may start even earlier, around 16 days after conception. The heart rate of a healthy fetus averages around 110 beats per minute at the fifth week of gestation, but increases to 170 beats by the ninth week. By the 13th week of pregnancy, it decreases to an average of 150 beats per minute. There was a belief that the heart rate of an unborn baby could reveal its gender through an ultrasound, however, multiple studies have shown that there is no noticeable difference in heart rate between male and female fetuses.
6. A Lab-Grown Beating Heart is Now a Reality
Researchers in Austria made a groundbreaking discovery in 2015 by successfully creating a functional "mini-heart" in a laboratory setting. This tiny, seed-sized heart was designed to imitate the activity of a 25-day-old human embryo's heart, providing scientists with a superior model to study the formation of congenital heart defects. The development of this lab-grown heart marked a shift from previous experiments which solely relied on animal subjects.
7. Mary Shelley Possessed Her Late Husband's Heart in Her Writing Desk
The author of the renowned novel "Frankenstein," Mary Shelley, had a strange connection to a detached heart. Upon the death of her husband, poet Percy Bysshe Shelley, his remains were cremated, but his heart reportedly refused to burn. It was recovered from the ashes and given to Mary, who treasured it within her writing desk. Decades later, the heart was finally laid to rest alongside the body of their son, Percy Florence Shelley, in 1889.