Ancient Greeks, including Hippocrates and Galen viewed the cardiovascular system as two distinct networks of arteries and veins. The very first conception comes from Erasistratus who believed that arteries and veins were separate. Veins contain blood, while arteries contain air. The portal veins take up food in the intestines, food is then delivered to the liver, transformed into blood and then transported to the vena cava by way of the hepatic vein. He hypothesized that, from the vena cava, venous blood was delivered to all parts of the body. Some of the blood would enter the right ventricle from where it was thought to be diverted to the pulmonary artery to nourish the lungs. In his model, air is taken up in the lungs by pulmonary veins, …show more content…
He was the first person to challenge the classic Galen School convention that blood could pass through the cardiac interventricular system (John B. West, Ibn al-Nafis, the pulmonary circulation, and the Islamic Golden Age). He believed that all the blood that reached the left ventricle passed through the lung and he introduced the concept of capillary circulation by stating there must be small communications or pores between the pulmonary artery and vein. Yet his work remained forgotten until 1924, the discovery of the vascular system is attributed to the English physicist William Harvey who described in 1628 the existence of the systemic circulation and properties of blood being pumped to the brain through physiological experiences led on dogs (De Motus Cordis). This was a major revolution to understand blood circulation (Fig). The presence of valves in the veins cued to the existence of unidirectional blood flow. In Harvey’s conception, the heart drives the mechanics of blood circulation and not the liver. Transfer of blood from arteries to veins in the lung and periphery may occur through direct connections or anastomoses or through porosities in the flesh (the latter mechanism being favored by
Although populations in ancient societies suffered attacks, invasions, starvation, and persecution, there was a more efficient killer that exterminated countless people. The most dreaded killers in the ancient world were disease, infections and epidemics. In many major wars the main peril was not gunfire, nor assault, but the easily communicable diseases that rapidly wiped out whole divisions of closely quartered soldiers. Until the time of Hippocrates, in the struggle between life and death, it was, more often than not, death that prevailed when a malady was involved. In the modern world, although illness is still a concern, advances in thought and technique have led to the highest birth rates in recorded history. No longer is a fever a cause for distress; a quick trip to the store and a few days of rest is the current cure. An infection considered easily treatable today could have meant disablement, even death to an ancient Greek citizen.
The circulatory system and respiratory system share a highly important relationship that is crucial to maintaining the life of an organism. In order for bodily processes to be performed, energy to be created, and homeostasis to be maintained, the exchange of oxygen from the external environment to the intracellular environment is performed by the relationship of these two systems. Starting at the heart, deoxygenated/carbon-dioxide (CO2)-rich blood is moved in through the superior and inferior vena cava into the right atrium, then into the right ventricle when the heart is relaxed. As the heart contracts, the deoxygenated blood is pumped through the pulmonary arteries to capillaries in the lungs. As the organism breathes and intakes oxygenated air, oxygen is exchanged with CO2 in the blood at the capillaries. As the organism breathes out, it expels the CO2 into the external environment. For the blood in the capillaries, it is then moved into pulmonary veins and make
In 1615 at the age of 37 Harvey became the Lumleian Lecture specializing in Surgery. William Harvey discovered his finding of the Circulation of Blood by ignoring medical textbooks and dissecting animals. He gained all or most of his learnings from observations of cutting open veins and arteries of living animals. Many people of this modern time thought because there weren’t any anesthetics that Harvey was cruel for cutting open living animals. I think that if it wasn’t for William Harvey and all of his studies and dissections that we wouldn’t be able to learn teach and save as many people as we can today. We as people have learned a lot from the many studies and dissections throughout Harvey’s lifetime. We have learned that blood, arteries, and veins are all within the same origin, blood in the arteries sent to the tissues are not stay there, the body‘s circulation mechanism was designed for the movement of liquid and that blood carrying air is still blood, the heart moves all movements of blood not the liver, hearts contract the same time as the pulse is felt, ventricle’s squeeze blood into main arteries, the pulse is formed by blood being pushed into arteries making them bigger, there are no vessels in the heart’s septum, lastly there is no to in from of blood in the veins there is only
The Mayo Clinic’s book on High Blood Pressure was full of detailed facts about blood pressure and what it is. This is extremely significant to the experiment because blood pressure is one of the variables being tested. Understanding blood pressure is one of the key components to receiving accurate results from this experiment. Most of the book is on high blood pressure, which is not necessary for the experiment, but the book still had plenty of useful information about blood pressure itself. The book explains that when the heart beats, a surge of blood is released from the left ventricle. It also tells of how arteries are blood vessels that move nutrients and oxygenated blood from the heart to the body’s tissues. The aorta, or the largest artery in the heart, is connected to the left ventricle and is the main place for blood to leave the heart as the aorta branches off into many different smaller
There he inspired many students and tutored them to become professionals in the medical field. Many of these students included Fabricius ab Aquapendente (gave the first clear description of the semi lunar valves of the veins, which later provided many people with a crucial point in his famous argument for circulation of the blood) and Volcher Coiter (described human embryology as well as the comparative osteology of animals and illustrated his own work.... ... middle of paper ...
Furthermore, Aristotle and Galen’s theories contributed to the Renaissance revival of heart anatomy. This reawakening made it possible for physicians to indicate the basic arrangement of the heart. It became commonly accepted that the heart was divided into four parts: two ventricles (lower chambers that pump blood out) and two auricles (upper chamber that r...
The cardiovascular system is divided into two systems a pulmonary and a systemic. Pulmonary division- blood flows from the heart to alveolar capillaries and back to the heart. Systemic division- blood flows from heart to every capillary “except alveolar” and back to heart.
The Structure and Functions of the Arteries Arteries are blood vessels that convey blood from the heart to the tissues of the body. The arteries expand and then constrict with each beat of the heart, a rhythmic movement that may be felt as the pulse. Arteries are usually named from the part of the body that they are found, for example; brachial artery found in the arms, metacarpal artery found in the wrist; or from the organ which they supply as the hepatic artery supplies the liver, pulmonary artery brings deoxygenated blood the lungs. The facial artery is the branch of the external carotid artery that passes up over the lower jaw and supplies the superficial portion of the face; the haemorrhoidal arteries are three vessels that supply the lower end of the rectum; the intercostal arteries are the arteries that supply the space between the ribs; the lingual artery is the branch of the external carotid artery that supplies the tongue. The structure of the artery enables it to perform its function more efficiently.
The pattern of blood flow starts in the left atrium to right atrium, then into the left ventricle and right ventricle. During its course, blood flows through the mitral and tricuspid valves. Simultaneously, the right atrium is granted blood from the veins through the superior and inferior vena cava. The job of the superior vena cava is to transport de-oxygenated blood to the right atrium. When your heart beats, the first beat represents the AV valves closing to prevent the backflow of blood into the atrium.
The heart serves as a powerful function in the human body through two main jobs. It pumps oxygen-rich blood throughout the body and “blood vessels called coronary arteries that carry oxygenated blood straight into the heart muscle” (Katzenstein and Pinã, 2). There are four chambers and valves inside the heart that “help regulate the flow of blood as it travels through the heart’s chambers and out to the lungs and body” (Katzenstein Pinã, 2). Within the heart there is the upper chamber known as the atrium (atria) and the lower chamber known as the ventricles. “The atrium receive blood from the lu...
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William Harvey was born on April 1, 1578, in Folkestone, England. At the age of sixteen, Harvey enrolled in Gonville and Caius College in Cambridge where he obtained a bachelor's degree in 1597. He went on to study medicine under Hieronymus Fabricius at the University of Padua in Italy. Fabricius was involved in the study of blood flow in the body, which motivated Harvey to research this branch as well. After moving to England, William Harvey was appointed as a personal physician to King Charles (Britannica). Within his study of blood, Harvey was able to form the theory of the circulation of blood through the body, which he published in ‘On the Motion of the Heart and Blood in Animals', in 1628. The book brought Harvey fame and made him a respected name in science. During his experiments, William Harvey became skeptical of pr...
Scientific interest in the heart goes back centuries. Some of the most basic understandings about the operation and specifically the electrical currents of the heart were discussed during the May 17, 1888 Proceedings of the Royal Society of London by Professor J.A. McWilliam of the University of Aberdeen. The following conclusions were based on his studies of mammalian hearts in cats, dogs, rabbits, rats, hedgehogs, and guinea-pigs.
of the air spaces and drops the air pressure in the lungs so that air