What do u know about working of human heart ?
606273
I know much about the heart. It's one of the most important organs in your body. (probably the most important if you want to stay alive). It is a very complicated system.\n\nYour question is too broad, I don't understand what you're trying to ask. Your question is more of an opinion one. If you have a particular question, I'd would be glad to answer.
1057101
Why study it?\nThere can hardly be a more fascinating subject to study than the human body. How do our muscles work? What makes us male or female? Why do some people sleep six hours a night and others nine? We study Human Biology in order to answer these and a host of other questions. Despite rapid advances in science there is still much to discover and learn about the body and the way it works. It is a very broad and richly varied subject that encompasses physiology, biochemistry, anatomy and cell biology. There is much in the course to choose from, depending on your own aims and interests. It has been structured to enable you to develop a good knowledge of our core areas, physiology and biochemistry, at the same time as allowing you to develop specialisms of your own. It will prepare you for a wide range of careers within industry, research and teaching.
19912
The entire heart is a pump. The whole thing contracts and expands 72 times a minute on average.  What is it's source of energy? Same thing as every other organ's source of energy. . .the food you eat, with the help of oxygen, food broken down into its constituent parts is what fuels the body.
848153
heart rate is defined as the number of beats( systoles) the heart produces per unit of time( ussually per minute).\nBlood pressure is the pressure exert by the blood to the vessel´s walls( the arteries and the veins).
467229
In the human body, the heart is normally situated slightly to the left of the middle of the thorax, underneath the sternum (breastbone). It is enclosed by a sac known as the pericardium and is surrounded by the lungs. The apex is the blunt point at the base of the heart. A stethoscope can be placed directly over the apex and count the beats. In normal adults, its mass is 250-350 g, but extremely diseased hearts can be up to 1000 g in mass. It consists of four chambers, the two upper atria (singular: atrium) and the two lower ventricles.\n\nA septum divides the right atrium and ventricle from the left atrium and ventricle, preventing blood from passing between them. Valves between the atria and ventricles (atrioventricular valves) maintain coordinated unidirectional flow of blood from the atria to the ventricles.The ventricular systole consists of the contraction of the ventricles and flow of blood into the circulatory system. Again, once all the blood empties from the ventricles, the pulmonary and aortic semilunar valves close. Finally complete cardiac diastole involves relaxation of the atria and ventricles in preparation for refilling with circulating blood.\n\nThe function of the right side of the heart (see right heart) is to collect deoxygenated blood from the body and pump it into the lungs so that carbon dioxide can be dropped off and oxygen picked up. This happens through a process called diffusion. The left side (see left heart) collects oxygenated blood from the lungs and pumps it out to the body. On both sides, the lower ventricles are thicker than the upper atria.\n\nOxygen-depleted or deoxygenated blood from the body enters the right atrium through two great veins, the superior vena cava which drains the upper part of the body and the inferior vena cava that drains the lower part. The blood then passes through the tricuspid valve to the right ventricle. The right ventricle pumps the deoxygenated blood to the lungs, through the pulmonary artery. In the lungs gaseous exchange takes places and the blood releases carbon dioxide into the lung cavity and picks up oxygen. The oxygenated blood then flows through pulmonary veins to the left atrium. From the left atrium this newly oxygenated blood passes through the mitral valve (also called the bicuspid valve) to enter the left ventricle. The left ventricle then pumps the blood through the aorta to the entire body. Even the lungs take some of the blood supply from the aorta via bronchial arteries.\n\nThe left ventricle is much more muscular (1.3 - 1.5 cm thick) than the right (0.3 - 0.5 cm thick) as it has to pump blood around the entire body, which involves exerting a considerable force to overcome the vascular pressure. As the right ventricle needs to pump blood only to the lungs, it requires less muscle.\n\nEven though the ventricles lie below the atria, the two vessels through which the blood exits the heart (the pulmonary artery and the aorta) leave the heart at its top side.\n\nThe contractile nature of the heart is due to the presence of cardiac muscle in its wall which can work continuously without fatigue. The heart wall is made of three distinct layers. The first is the outer epicardium which is composed of a layer of flattened epithelial cells and connective tissue. Beneath this is a much thicker myocardium made up of cardiac muscle. The endocardium is a further layer of flattened epithelial cells and connective tissue which lines the chambers of the heart.\n\nThe blood supply to the heart itself is supplied by the left and right coronary arteries, which branch off from the aorta.
1114301
Through veins, artilleries and capillaries powered by the pumping motion of the heart. \n☆
791319
look at the noted citation\n \n   \nWhat Is ...  \nHow the Heart Works  \nCauses  \nSigns & Symptoms  \nDiagnosis  \nTreatments  \nLiving With  \nKey Points  \nLinks  \n \n    What Is Atrial Septal Defect? \nAn atrial septal defect (ASD) is a hole in the wall (septum) that separates the two upper chambers (atria) of the heart. The defect allows blood to flow from one atrium to the other, usually from the left side to the right side. This causes extra blood flow:\n\nIn the right atrium \nIn the right ventricle \nTo the lungs \n\n\nFigure A shows the normal anatomy and blood flow of the interior of the heart. Figure B shows a heart with an atrial septal defect, which allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood from the right atrium. \n\nIn a normal heart, oxygen-poor (blue) blood returns from the body to the right atrium. From the right atrium, the blue blood flows to the right ventricle—one of the two lower chambers of the heart—and is pumped to the lungs to pick up oxygen. After traveling through the lungs, the blood is now oxygen-rich and red. The red blood returns from the lungs to the left atrium and goes to the left ventricle, where it is pumped to the body. The right and left sides of the heart are normally completely separated by the septum. The septum keeps the blue blood from mixing with the red blood. The later section "How the Heart Works" explains the process in greater detail.\n\nASD is the second most common congenital heart defect.\n\nMore than 3,000 babies are born with ASD each year in the United States. \nASD occurs twice as often in girls as in boys. \nEffects of Atrial Septal Defect\nOver time, the extra blood flow to the right side of the heart and the lungs can cause:\n\nEnlargement of the right atrium and the right ventricle. \nRight heart overload. The right side of the heart has to work harder to pump extra blood to the lungs, especially as resistance in the pulmonary (PULL-mun-ary) artery increases. Over time, the heart may become overworked, and function may become impaired. This is exceedingly rare with modern methods of diagnosis and treatment. \nIrregular heartbeats or rhythms (arrhythmias). Extra blood flowing into the right atrium through the ASD can cause the atrium to stretch and enlarge. When this occurs, a fast heartbeat can develop with symptoms such as dizziness, fainting, or chest discomfort. \nStroke. Occasionally a blood clot in a vein or in the right side of the heart can pass through the ASD and enter the blood stream, where it can block an artery supplying the brain and cause a stroke. \nPulmonary artery hypertension. This is when high blood pressure exists in the arteries that carry blood to the lungs. The extra blood being pumped to the lungs can increase the pressure in the pulmonary arteries. Over time, high pressure can damage the arteries and the small blood vessels in the lungs. They thicken and become stiff, making it harder for blood to flow through them (pulmonary vascular disease). \nUsually, most of these effects don’t show up until adulthood, often around age 30 or later. They are rare in infants and children.\n\nCharacteristics\nAn ASD is classified by its size and location.\n\nSize\nThe size of an ASD can range from small to large.\n\nMost small defects close on their own as the heart grows during childhood. They usually allow only a small amount of blood to flow between the atria. \nModerate to large defects are much less likely to close on their own. They allow two or more times the normal amount of blood to flow through the right side of the heart. Large holes sometimes cause symptoms during infancy or childhood. \nLocation\nThree major types of ASD exist, based on the location of the defect on the septum:\n\nSecundum. This defect is in the middle of the septum. It is the most common form of ASD. About 7 out of every 10 babies born with ASD have this type. This type often closes on its own, unless it is large. \nPrimum.
338856
Heart Hands Head Health.
31165
* Cardiovascular system: blood circulations with heart and blood vessels\n    * Digestive system: processing food with mouth, stomach and intestines\n    * Endocrine system: communicating within the body using hormones\n    * Immune system: defending against disease-causing agents\n    * Integumentary system: skin, hair and nails\n    * Lymphatic system: structures involved in the transfer of lymph between tissues and the bloodstream\n    * Muscular system: moving the body\n    * Nervous system: collecting, transferring and processing information with brain and nerves\n    * Reproductive system: the sex organs\n    * Respiratory system: the organs used for breathing, the lungs\n    * Skeletal system: structural support and protection through bones\n    * Urinary system: the kidneys and associated structures involved in the production and excretion of urine
1163412
It is theoropy related to breating and heart beating.
67467
No.  The heart is just a muscle.  If you exercise, it beats more, but gets stronger and lasts longer.
278754
I believe the primary reason for the slow development of the artifical heart is the power pronblem.\n\nThe human heart is a very ppowerful pump.  It has been very difficult to creat something small enough to fit in the space where the heart is located and still provide the same power curve that the normal human heart displays.\n\nEarly artifical hearts were powered externally (outside the body).  Later artifical hearts were powered internally but the pumping action was ;icated outside the hearst compartment.\n\nMy explantion above is my own personal knowledge, here is a link that might help...\n\nhttp://en.wikipedia.org/wiki/Artificial-heart\nhttp://www.chron.com/content/chronicle/metropolitan/heart/heart-history.3-0.html\nhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6729956&dopt=Abstract\n\n\nI hope this gives you a good start.\n\nBest of luck,\nJeffrey
947204
Look up \nhttp://drchander.com/heartmurmurfaq.html
1098733
The average human heart beats approximately two billion times in a lifetime.
915974
http://www.rjmatthewsmd.com/Definitions/anatomy_ofthe_heart.htm
537540
Objectives: to identify the heart as the largest muscle in the body, to describe the heart's role in pumping blood to the lungs and to all parts of the body \n\n \nProcedures:  \nStudent Information: Ask students to identify the strongest muscle of the body. Allow students to give their ideas and then explain that the correct answer is the heart. Show students diagram of the heart and share the background information with them.  \nThe heart works day and night to pump blood through the circulatory system. \nThe heart consists of two pumps. \nThe pump on the right side of the heart sends blood to the lungs where the blood obtains oxygen. \nThe blood which has obtained oxygen then travels back to the heart where it is pumped to all parts of the body. \n\nI hope this helps...
1003119
look at this 3D pic then read\n\nhttp://library.thinkquest.org/C003758/rotate.htm\n\nIn the human body, the heart is normally situated slightly to the left of the middle of the thorax, underneath the sternum (breastbone). The heart is usually felt to be on the left side because the left heart (the left part of the heart) is stronger (it pumps the blood out). The heart is enclosed by a sac known as the pericardium and is surrounded by the lungs.Betwen the pericardium and the heart there is a serous fluid to reduce friction during heart contractions. The apex is the blunt point at the base of the heart. A stethoscope can be placed directly over the apex and count the beats. In normal adults, its mass is 250-350 g (8-11 oz), but extremely diseased hearts can be up to 1000 g (2 lb) in mass. It consists of four chambers, the two upper atria (singular: atrium ) and the two lower ventricles. On the right is a picture of a fresh human heart which was just removed from a 64 year old British gentleman. The mass for a thin white male is usually 270-300 grams (9-11 ounces) with little fat.\n\nA septum divides the right atrium and ventricle from the left atrium and ventricle, preventing blood from passing between them. Valves between the atria and ventricles (atrioventricular valves) maintain coordinated unidirectional flow of blood from the atria to the ventricles. The ventricular systole consists of the contraction of the ventricles and flow of blood into the circulatory system. Again, once all the blood empties from the ventricles, the pulmonary and aortic semilunar valves close. Finally complete cardiac diastole involves relaxation of the atria and ventricles in preparation for refilling with circulating blood.\n\nThe function of the right side of the heart (see right heart) is to collect deoxygenated blood from the body and pump it into the lungs (pulmonary circulation)so that carbon dioxide can be dropped off and oxygen picked up. This happens through a process called diffusion. The left side (see left heart) collects oxygenated blood from the lungs and pumps it out to the body (systemic circulation). On both sides, the lower ventricles are thicker than the upper atria.\nOxygen-depleted or deoxygenated blood from the body enters the right atrium through two great veins, the superior vena cava which drains the upper part of the body and the inferior vena cava that drains the lower part which drains the portal cyrculation too full with nutrients to nourish the body. The blood then passes through the tricuspid valve to the right ventricle. The right ventricle pumps the deoxygenated blood to the lungs, through the pulmonary artery. In the lungs gaseous exchange takes places and the blood releases carbon dioxide into the lung cavity and picks up oxygen which is called external respiration. The oxygenated blood then flows through pulmonary veins to the left atrium. From the left atrium this newly oxygenated blood passes through the mitral valve (also called the bicuspid valve) to enter the left ventricle. The left ventricle then pumps the blood through the aorta to the entire body. Even the lungs take some of the blood supply from the aorta via bronchial arteries.\n\nThe left ventricle is much more muscular, which is 1.3 - 1.5 cm (.5-.6 in) thick, than the right, 0.3 - 0.5 cm ( .1-.2 in) thick, as it has to pump blood around the entire body, which involves exerting a considerable force to overcome the vascular pressure. As the right ventricle needs to pump blood only to the lungs, it requires less muscle.\n\nEven though the ventricles lie below the atria, the two vessels through which the blood exits the heart (the pulmonary artery and the aorta) leave the heart at its top side.\n\nThe contractile nature of the heart is due to the presence of cardiac muscle in its wall which can work continuously without fatigue. The heart wall is made of three distinct layers. The first is the outer epicardium which is composed of a layer of flattened epi