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In the US, heart attacks kill more people than any other single cause. Many of the deaths are caused by electrical disturbances in a damaged heart that cause it to fibrillate (Pool). Despite current overwhelming interest in the operations of the human heart, for most of history the human heart has been regarded as a "forbidden organ too delicate to tamper with" (NOVA). In fact, it might have remained so, were it not for World War II where military doctors, faced with massive numbers of injuries ushered the world into our current medical trajectory.
Your body has about 5.6 liters of blood. All of this blood circulates through the body three times every minute. In one day, the blood travels a total of 12,000 miles (NOVA). Rhythmic contractions of the heart pump blood occur in response to electrical control pulse sequences. Active cells in the sinoatrial node in the heart trigger a sequence of electrical events that control muscle contractions, which pump the blood.
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.
* An all or nothing approach to heart contraction
o If a stimulus was strong enough to excite contraction, it produced a maximal contraction
* The application of interrupted currents induces fibrillar contractions which can be recovered from even after long period under the combined influence of artificial respira...
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...n that prevents the heart from immediately contracting again.
Bibliography
1. "Cactus Picture" March 16, 2005.
2. Campbell, Neil A. (2002) "Biology" 6th edition. Benjamin Cummings. San Francisco, CA.
3. Kay, Ian. (1998) "Introduction to Animal Physiology" Springer-Verlag New York Inc.
4. McWilliam, J.A. (1888) "On the Rhythm of the Mammalian Heart" Froceedings of the Royal Society of London, Vol. 44, pages 206-208.
5. NOVA. " Cut to the Heart” PBS Online 1997.
6. Pool, Robert. (1990) “Heart Like a Wheel” Science, Vol. 247, No. 4948, pages 1294-1295.
7. Putnam, Jeremiah L. "Heart Diagram" Professor of Biology. Davidson College.
8. Schmidt-Nielsen, Knut. (1997) "Animal Physiology: Adaptation and environment" Fifth Edition. Cambridge University Press. New York, NY.
1.2 & 1.3 Explain The Cardiac Cycle And Describe How The Heart Rate Is Modified According To The Needs Of The Body
O’Rourke [13] describes the pulse wave shape as: “A sharp upstroke, straight rise to the first systolic peak, and near-exponential pressure decay in the late diastole.” Arteries are compliant structures, which buffer the pressure change resulting from the pumping action of the heart. The arteries function by expanding and absorbing energy during systole (contraction of the cardiac muscle) and release this energy by recoiling during diastole (relaxation of the cardiac muscle). This function produces a smooth pulse wave comprising a sharp rise and gradual decay of the wave as seen in Figure 5. As the arteries age, they become less compliant and do not buffer the pressure change to the full extent. This results in an increase in systolic pressure and a decrease in diastolic pressure.
of the heart: one chamber is on the top and one chamber is on the
The science and history of the heart can be traced back as far as the fourth century B.C. Greek philosopher, Aristotle, declared the heart to be the most vital organ in the body based on observations of chick embryos. In the second century A.D, similar ideas were later reestablished in a piece written by Galen called On the Usefulness of the Parts of the Body. Galen’s thesis was that the heart was the source of the body’s essential heat and most closely related to the soul. Galen made careful observations of the physical properties of the heart as well. He said “The heart is a hard flesh, not easily injured. In hardness, tension, in general strength, and resistance to injury, the fibers of the heart far surpasses all others, for no other instrument performs such continues, hard work as the heart”(Galen, Volume 1).
Chua, John. "An overview of 'The Tell-Tale Heart,'." Gale Online Encyclopedia. Detroit: Gale, 2010. Literature Resources from Gale. Web. 7 Dec. 2010.
VanPutte, C., Regan, J., & Russo, A. (2014). Seeley's anatomy & physiology(10th ed.). NEW YORK, NY: MCGRAW-HILL.
Approximately one million Americans suffer a heart attack annually. Four hundred thousand of these victims die as a result. Many of the heart attack deaths are due to ventricular fibrillation of the heart that occurs before the victim can reach any medical assistance or the emergency room. These electrical disturbances of the heart can be treated with medications once the patient reaches the hospital. Therefore, 90% to 95% of heart attack victims who make it to the hospital survive. The 5% to 10% who later die are those who have suffered major heart muscle damage.
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...
The cardiovascular system is made up of the heart which pumps blood to the lungs through pulmonary circulation, the heart muscle through cardial circulation and the body systems through systematic circulation. It is made up of various chambers and valves and its cycle is controlled by an electrical signal originating in the heart itself. There are various different vessels which control the blood flow throughout the body. Which include high pressure arteries and arterioles originate from the heart. Capillaries which have a semipermeable membrane that allows the exchange of gasses, nutrients and wastes between the blood and the tissues. Also veins which are low pressure and contain valves that prevent backflow. All of these together perform the main functions of the cardiovascular system; protection, transportation and regulation.
Martini, Nath, Bartholomew. (2012). Fundamentals of Anatomy and Physiology Ninth Edition. In N. B. Martini, Fundamentals of Anatomy and Physiology Ninth Edition (pp. Chapter 25; 917-952). San Francisco: Pearson Education.
The Heart is a very important organ in the body. It is what keeps your blood flowing and your organs going. It is a tireless muscle that pumps more than two thousand gallons of blood every day. The blood that is pumped is filled with nutrition and oxygen (Colombo 7). It travels through out your body in less than sixty seconds. So it needs to be taken extra good care of. When abuse is put on the body, the heart’s performance is not at its best. The Heart is a major organ that needs loving and care. Everyone has only one and by abusing it, they are cutting their live span little by little. People can live their lives freely but how they choose to live them could be the difference between life and death.
Works Cited Bates, D. (1957, December 17). Letter from Roy Wilkins. Little Rock, Arkansas, United States of America. Beals, M. P. (1994). The Species of the World.
The heart is not hard to imagine in ones mind because it is simply a two sided, four chambered pump. The heart is mostly made of muscle and is very unique because it is the only muscle that does not become tired like other muscles. . Imagine what would happen if every 15 minutes or so ones heart becomes tired and decides to take a little break! If this were to happen it basically means that in a few moments ones circulatory system will shut down since the heart is the powerhouse of this system. Since it never rest, the heart muscle is always expanding and contracting, usually at between 60 and 100 beats per minute.
The circulatory system consists of many different components and structures for specific functions. For example controlling the blood flow to go one direction, for one blood vessel to hold more blood than another, and even a system that decides when the heart beats. As the circulatory system was studied and observed, questions were raised of how the blood flow goes only one way. In the heart and between each chamber, there are four valves that control the amount of blood flow in the heart. As the oxygen poor blood flows into the right atrium through the respective vena cava’s, it is stopped until the heart contracts and the tricuspid valve opens, letting the blood flow into
The human heart is one, if not the most, vital organ in the human body. The heart pumps blood through the circulatory system. It is what provides the body with oxygen and nutrients. Of course, without this important, muscular, organ there would be no way to survive. “Everyday your heart beats about 100,000 times, sending 2,000 gallons of blood surging through your body. Although it is no bigger than your fist, your heart has a mighty job of keeping blood flowing through 60,000 miles of blood vessels that feed your organs and tissues” (Watson n.pag.). Any type of damage or restriction to the heart or its valves can reduce pumping. Cardiovascular diseases are examples that cause damage to the heart and blood vessels. Cardiovascular disease is the most common cause of death globally, accounting for thirty percent of deaths. Since the heart has such an important role in the human body, it is critical that it is functioning and working properly. An important medical test used to observe the heart is called transesophageal echocardiography, also known as TEE.