How does the human heart work?

Answer 1

The horse's heart works basically the same as ours. Four chambers and valves between them. We are not that different at that level - humans and horses are both mammals and all mammals have similar hearts.

Answer 2

In mammals, the function of the right side of the heart is to collect de-oxygenated blood, in the right atrium, from the body (via superior and inferior vena cavae) and pump it, via the right ventricle, into the lungs (pulmonary circulation) so that carbon dioxide can be dropped off and oxygen picked up (gas exchange). This happens through the passive process of diffusion. The left side collects oxygenated blood from the lungs into the left atrium. From the left atrium the blood moves to the left ventricle which pumps it out to the body (via the aorta). On both sides, the lower ventricles are thicker and stronger than the upper atria. The muscle wall surrounding the left ventricle is thicker than the wall surrounding the right ventricle due to the higher force needed to pump the blood through the systemic circulation.

Starting in the right atrium, the blood flows through the tricuspid valve to the right ventricle. Here, it is pumped out the pulmonary semilunar valve and travels through the pulmonary artery to the lungs. From there, blood flows back through the pulmonary vein to the left atrium. It then travels through the mitral valve to the left ventricle, from where it is pumped through the aortic semilunar valve to the aorta. The aorta forks and the blood is divided between major arteries which supply the upper and lower body. The blood travels in the arteries to the smaller arterioles and then, finally, to the tiny capillaries which feed each cell. The (relatively) deoxygenated blood then travels to the venules, which coalesce into veins, then to the inferior and superior venae cavae and finally back to the right atrium where the process began.

The heart is effectively a syncytium, a meshwork of cardiac muscle cells interconnected by contiguous cytoplasmic bridges. This relates to electrical stimulation of one cell spreading to neighboring cells.

Some cardiac cells are self-excitable, contracting without any signal from the nervous system, even if removed from the heart and placed in culture. Each of these cells have their own intrinsic contraction rhythm. A region of the human heart called the sinoatrial node, or pacemaker, sets the rate and timing at which all cardiac muscle cells contract. The SA node generates electrical impulses, much like those produced by nerve cells. Because cardiac muscle cells are electrically coupled by inter-calated disks between adjacent cells, impulses from the SA node spread rapidly through the walls of the artria, causing both artria to contract in unison. The impulses also pass to another region of specialized cardiac muscle tissue, a relay point called the atrioventricular node, located in the wall between the right artrium and the right ventricle. Here, the impulses are delayed for about 0.1s before spreading to the walls of the ventricle. The delay ensures that the artria empty completely before the ventricles contract. Specialized muscle fibers called Purkinje fibers then conduct the signals to the apex of the heart along and throughout the ventricular walls. The Purkinje fibres form conducting pathways called bundle branches. The impulses generated during the heart cycle produce electrical currents, which are conducted through body fluids to the skin, where they can be detected by electrodes and recorded as an electrocardiogram (ECG or EKG).

The SA node is found in all amniotes but not in more primitive vertebrates. In these animals, the muscles of the heart are relatively continuous and the sinus venosus coordinates the beat which passes in a wave through the remaining chambers. Indeed, since the sinus venosus is incorporated into the right atrium in amniotes, it is likely homologous with the SA node. In teleosts, with their vestigial sinus venosus, the main centre of coordination is, instead, in the atrium. The rate of heartbeat varies enormously between different species, ranging from around 20 beats per minute in codfish to around 600 in hummingbirds.

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Cardiac arrest is the sudden cessation of normal heart rhythm which can include a number of pathologies such as tachycardia, an extremely rapid heart beat which prevents the heart from effectively pumping blood, fibrillation, which is an irregular and ineffective heart rhythm, and asystole, which is the cessation of heart rhythm entirely.

Cardiac tamponade is a condition in which the fibrous sac surrounding the heart fills with excess fluid or blood, suppressing the heart's ability to beat properly. Tamponade is treated by pericardiocentesis, the gentle insertion of the needle of a syringe into the pericardial sac (avoiding the heart itself) on an angle, usually from just below the sternum, and gently withdrawing the tamponading fluids.

Answer 3

The human heart works by first having blood flowing into the right atrium. Then the blood is moved to the right ventricle where the blood is pumped to the lungs through the pulmonary artery. Next in the lungs blood that is rich in carbon dioxide is switched with blood that is rich in oxygen. The blood then flows back into the heart through the pulmonary veins which leads to the left atrium. Then the blood is pumped from the left ventricle to the aorta which pushes all that blood to every part of the body. In the body, the blood that is rich in oxygen is given to the body so that cellular respiration can occur. Next, the blood from the body that is rich in carbon dioxide is pushed back to the heart through the superior and inferior vena cava which flows back to the right atrium.

Answer 4

They're not very different at all, a horse heart is just much larger, but we both have a mammalian 4-chambered heart that beats warm blood. Secretariat had the largest horse heart ever recorded, 12 pounds, if memory serves.

Answer 5

Blood is sent to the heart's right atrium through the superior vena cava, inferior vena cava, and pulmonary veins. This blood is deoxygenated. The walls of the atria contract and sends blood to the ventricle through the atrioventricular valve, which closes when the blood fills the right ventricle to prevent backflow. The sinoatrial node then sends a signal to the atrioventricular node to contract the walls of the ventricles 0.1 seconds after the atria contract. Blood is then sent through the semilunar valve and to the lungs through the pulmonary arteries. Blood then goes through the gas exchange process in the alveoli located within the lungs. It then returns to the heart as oxygenated blood through the pulmonary veins, which go through a similar process as the deoxygenated blood in the right atrium and ventricle. Blood enters the left atrium through the pulmonary veins. The left atrium contracts and sends blood to the left ventricle through the atrioventricular valve, which closes after blood has completely entered the left ventricle to prevent backflow. The walls of the ventricle then contract 0.1 seconds after the atrium contracts, and sends blood to the rest of the body through the aorta after flowing through the semilunar valve.

Answer 6

(how does the heart work)

well the heart pumps blood through the body and the heart also helps you live.

There are many different ways that the heart works....

Answer 7

Yes, the function of a horse's heart is to pump blood. Pumping blood is the function of all animals' hearts.