Heart

The valves have to open to let blood flow into a chamber, and close before the blood flows back. If the valves do not open and close precisely on schedule, or if they fail to open or close completely, the blood will not flow efficiently. This can cause fluctuations in blood pressure, lack of flow to organs, or damage to the muscles of the heart.

For example, if the aortic valve between the heart and the aorta does not close after the left ventricle contracts, there will be back pressure into the ventricle, less blood pumped out of the heart, and lower pressure in the arteries.

Transplanting organs from animals to humans (xenotransplantation, pronounced "zee-no-transplantation") is rarely performed in real life. However the "theme" of xenotransplantation seems to be quite prevalent in fictional novels/tv series which to some extent spreads the public misconception that it is a common occurrence.

Xenotransplantation is rarely performed, since at a basic level, it just does not work. The organs do not perform nearly as well as a human-to-human transplanted organ (referred to as "allotransplantation", but often shortened to just "transplantation". "Allo" indicates that the organ is from the same species as the recipient). Is the vast majority of cases, a xenograft (the organ used in a xenotransplant) will either fail to function, or reject within a few days of the operation. This is one reason why they are extremely rarely used.

The situation in which you may hear of an animal organ being used is when a patient is absolutely critically ill, and a time-gap (of around 2 or 3 days) has to be bridged until a suitable human organ can be found. These cases happen exceedingly rarely; in many cases skilled transplant surgeons would not even contemplate/ be given the official clearance to perform this procedure, due to the problems with medical ethics and sourcing of the suitable animal organ at short notice. Even in situations with critically-ill patients, xenotransplantation is an incredibly uncommon occurrence.

Xenotransplantation is currently never used as a "permanent" solution - that's what allotransplantation is used for.

To answer your question specifically, with current medical advances it still would not be a good idea to have a xenotransplant of a pig heart, since there is a huge risk of it not functioning properly, or rejecting. For the time being, stick to human organs.

There is currently research into how to make organs from animals (mainly pigs and sheep) "humanised" for use in transplantation, so that the rate of organ rejection is minimised. But this is still very early research. These organs are nowhere near ready for any practical use in transplantation. And even if they were of practical use, the option of an allotransplant would still be around for a long time subsequently.

For more information, please see related link.

Out of all transplant-able organs, hearts deteriorate the quickest without a blood supply. This means that time between harvesting the organ and it being stitched into the recipient needs to be as small as possible, in order to guarantee the best chance of success. Often, this means that the time the organ can stay in transit is very minimal, so the organ does not always get to the person most in need of it - instead it goes to the person within easiest geographical reach.

The average adult human heart weighs about 300 grams in men, and about 200 grams in women although it varies with the size and weight of the person as well as how muscular the heart is.

The approximate weight of the human heart is 0.5% of a person's weight.

yes

As you probably know, the heart has 2 sides, and 4 parts, 2 atrium's and ventricle's, the right side of the heart is responsible for taking in the de-oxygenated blood, and transferring it to the lungs, the lungs pump the newly oxygenated blood to the left side of the heart and then the heart pumps it everywhere around the body. I hope this helps you, i know this info helped me get an A+ in my science test!!!!

OK, if its a nautical star I have heard tell it means anti-racism and the love of man as a brotherhood. But I cant say that for a fact.

If it a solid blue star it could mean the love and care for a family member in the services. A blue star in a window signified a son over seas in a war zone.

Hope I helped....TatuBaron

In the nautical world, a red star symbolizes a passage around the Cape of Good Hope on a sailing ship, and a blue star signifies passage of Cape Horn, which was much more difficult.... Seadog

Blood coming back from the body via the Vena Cava enters the right atrium. Blood coming back from the lungs enters the left atrium

Every single part of your body is made up entirely of cells or pseudo cells. The heart is made up of Cardiac Muscle cells. These are similar to skeletal muscle in that they are stirated but have many differences, most importantly a very unstable Membrane Potential.

Death is medically defined as cesation of the heart beating. Once the heart has stopped beating, you have between 2-6 minutes to get the heart restarted before mild to severe brain damage occurs. During this time, performing CPR can stave off the effects to some extent. In other words, if a person has a heart attack and their heart has stopped, performing CPR on the downed person will sustain the brain getting the necessary oxygen to stay alive as well the allow the heart to perfuse or send blood to vital organs throughout the body. However if the heart is not able to be restarted during this time, then the person is dead. So to Answer the question, if someone is "down" for 20 minutes, with their heart stopped, and it is restarted, there is an extremely high probability of irreversible brain damage/persistent vegetative state. In other words, they are brain dead and not alive even though their heart is still beating. So . . . NO a person cannot live again after their heart has been stopped for 20 minutes.

The 'lub' is the S1 sound. It occurs due to normal closure of the mitral and tricuspid (atrioventricular) valves. With these valves closed, systole commences and blood is actively squeezed from the ventricles. The second sound is the 'dub' or S2 sound. It occurs as the aortic (to LV) and pulmonary (to RV) valves close to prevent backflow from the blood ejected from the ventricles and marks the beginning of diastole (or filling) of the heart.

Myocardium

The muscles used to produce a heartbeat are called the "heart."

the heart is an organ while it is a part of the circulatory system

Start in the superior and inferior vena-cava, moves to the right atrium, goes through the tricuspid valve to the right ventricle. The blood then goes through the pulmonary semi-lunar valve to the pulmonary artery (which contains oxygen poor blood). This then goes to the lungs where the oxygen poor blood is oxygenated and comes back to the heart via the pulmonary vein (which contains oxygen rich blood).

It pumps blood all around the body.

-Anonymous

Right ventricle and pulmonary artery

If one of the arteries attached to your heart started to "leak", it would not cause high blood pressure. The rest of your arteries would clog up with too much blood, and would cause your heart to pump double time, and if your heart pumped double time, you would be at risk for a heart attack. Depending on how fast your heart is beating, you would have to be opperated on. If this ever happens, you should be rushed straight to the emergency room.

Dr. Robert Jarvik, invented the artificial heart.

Calf Muscles is called as the peripheral heart as its action pumps the deoxygenated blood back to the heart against the gravity. it is composed of soleus, medial and lateral gastrocnemius muscles situated in the posterior part below the knee or the upper leg.

Right Atrium, right ventricle, lungs, left atrium, left ventricle, then it goes all over the body, comes back to the heart and repeats the process. For the heart to function properly, the four chambers must beat in an organized manner. The four heart chambers fill with and pump blood. The right and left atria pump blood to the right and left ventricles respectively. The four heart valves are: 1. the tricuspid valve, located between the right atrium and right ventricle; 2. the pulmonary or pulmonic valve, between the right ventricle and the pulmonary artery; 3. the mitral valve, between the left atrium and left ventricle; and 4. the aortic valve, between the left ventricle and the aorta. Each valve has a set of flaps (also called leaflets or cusps). The mitral valve has two flaps; the others have three. Under normal conditions, the valves permit blood to flow in only one direction. Blood flow occurs only when there's a difference in pressure across the valves that causes them to open. Blood returning to the heart from the body (venous blood that has already had oxygen taken from it) enters the right atrium. Blood flows and is pumped from the right atrium across the open tricuspid valve into the right ventricle. As the right ventricle starts to contract the tricuspid valve closes (blood can only be pumped forward) the pulmonic valve opens and blood pumped into the pulmonary arteries. These arteries carry blood to the lungs to be oxygenated.Oxygenated blood is returned to the heart by pulmonary veins. This oxygenated blood enters the left atrium. Blood from the left atrium flows across an open mitral valve to enter the left ventricle. As the left ventricle starts to contract the mitral valve closes and the aortic valve opens as blood is pumped across it into the aorta.The aorta and arteries that branch from it carry blood to the entire body. The left ventricle is the largest and most forcefully contracting chamber of the heart. It must pump oxygen rich blood to the whole body.

Stroke-Volume

This happens when a patient's heart stops beating and the oscilloscope measuring their heartbeat shows nothing but a static line - hence "flatlined."

Water around the heart is also called a pericardial effusion. The pericardium is a sac that surrounds the heart. If this sac fills with fluid, a pericardial effusion, then the ability of the heart to contract normally is compromised.

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