This geocache can be found close to the HEART of Loveland. I hope you enjoy a look back at the Scientists who first discovered what our beating hearts actually do.
Our Circulatory System is an amazingly complex interconnected system of vessels that distribute oxygen and nutrients to the trillions of cells in our body. The heart is a powerful muscle that pumps the blood to the extremities through the arteries and then returns to the heart through the veins. Our red blood cells re-stock with oxygen in the lungs and export Carbon Dioxide. After eating we get the energy from our food through the connection between the digestive and circulatory systems. It’s hard to imagine that the basics of the circulatory system weren’t understood for centuries of humanity’s existence.
In the 2nd century AD, famous Greek physician and Philosopher Galen of Pergamon established the earliest theories about our circulatory system. Galen was born in Modern day Turkey in 129 AD. He establishing himself in Rome and became a prominent member of roman society, serving as physician to several emperors. Galen’s contributions to Medicine were mis-informed, owing largely to the long-held theory of Humors, in which physicians believed that a person’s mood was affected by 4 body fluids including yellow bile, black bile, phlegm, and blood. Galen was the first to notice a difference between arterial blood and venous blood. Unfortunately, the conclusions he came to were totally wrong. He proposed that there were TWO separate one-way tracks for blood in the body. He believed that Venous blood was made by the Liver and arterial blood by the heart. Additionally he proposed that all of the blood was “consumed” by the tissues of the body. His theories were of course largely incorrect and could not be used to implement any practical medical advances.
Following his death, it would only seem logical that the understanding of the circulatory system would have increased through the centuries. Unfortunately when Rome fell, the Middle Ages brought very few scientific advances. In fact, 1500 years after Galen’s death modern medicine’s understanding of the Circulatory System hadn’t advanced at all. AT ALL!!!
In the mid 1500s new ideas surrounding the circulatory system started popping up throughout Europe. It wasn’t until William Harvey’s 1628 publication “De Motu Cordis” that it became clear that the heart pumps blood in a circuit returning to the heart, refuting the long held belief that blood was consumed by the tissues then remade. Harvey also squashed Galen’s proposal that the Liver produced blood. Harvey calculated the amount of blood the Liver would have to be constantly producing using Galen’s theory, and it quickly made no sense. Additionally he used math to confirm his theory that blood travels in a circuit. The heart pumps between 55 and 80ml(⅓ cup) of blood per beat. The average heart pumps 250-312 liters an hour… 6,000-7,500 liters of blood a day. There is no logical way that the ~3 pound liver and one pound heart could produce this amount of blood so quickly. He concluded that the blood wasn’t being consumed at all, but was instead being re-circulated.
William Harvey grew up in an upper-class family and was the oldest of Nine siblings, six brothers and two sisters. His early education all occurred in Folkshire then Cambridge England. After earning his Bachelor’s degree in 1597. After graduation he traveled through France, Germany,then Italy. He earned his Doctorate from the University of Padua in 1602. Right after graduation Harvey returned to England and earned another Doctorate of Medicine from the University of Cambridge. Harvey took a position at St. Bartholomew’s Hospital, and worked there for most of his remaining years. He was taking only 33 pounds a week for compensation and lived in a humble home. He took pride in providing for the poor and underserved.
Harvey began an extended period of lecturing on Anatomy in 1616 while still working at St. Bartholomew. His fame grew and even became the Physician to James I the King of both Scotland and England. William Harvey was cemented in the history books with his breakthrough publication De Motu Cordis in 1628. In this text he was the first to describe that blood leaves and returns to the heart in a circuit as it pumps. He also describes that there are valves in veins that only allow blood to move ONE-WAY back to the heart. Most of his work was initially done in fish and snakes. He dissected them while they were still alive. He noticed that if he tied-off veins, the heart would empty, and if he tied off arteries the heart would swell. He further confirmed his theories in humans, forever changing the world’s understanding of the circulatory system.
The England Witch trials were in full swing during Harvey’s years as a doctor. William was an outspoken critic of the trials in the 1620s and 30s. Being of very high stature in the medical community, he inserted himself as an “examiner” of many accused witches, resulting in the acquittal of many women. In 1632 William became the day-to-day Physician for King Charles I. This wasn’t a great position, as England found itself in a civil war, forcing Charles I to flee to Oxford with Harvey in-tow. Harvey remained with Charles until his eventual surrender and Charles’ execution. Following the surrender William was 68 years old and largely retired from working in the medical field.
He died in London on June 3rd 1657 at his Brother Elijah’s home. He died as a result of a malfunction in the same system that made him famous. He had a cerebral hemorrhage due to years of weakened vasculature from gout.
N40 AB.CDE W105 FG.HJK
A = William Harvey’s famous De Motu Cordis was published in 16__8.
B = Dr. Harvey died in 16__7.
C = The Liver weighs about ____ pounds.
D = Harvey was the Physician for King Charles ____ until Charles surrendered in Oxford during Civil War.
E = Galen was a Greek physician, scientist, and philosopher producing his most influential work during the ___ Century.
F = The number of physicians or scientists before 1628 that described the circulatory system as a circuit.
G = The long debunked theory of Humorism suggested that the amounts of____ main bodily fluids were responsible for the health and temperament of humans.
H = William Harvey earned his Bachelor’s degree in 15__7
J = William had ____ sisters.
K = Galen was born in 1__9 AD.
This Geocache was created and is maintained by Stanley Polley, a Science teacher at Mackintosh Academy.
You can check your answers for this puzzle on GeoChecker.com.
