Question

Write an essay about the mechanism of heart, 100-150 words.

Answer 1

The following points can be used to write an essay.

The first paragraph of an essay should be an introduction about the heart and its structure. Following a few pointers can be used for introduction.

* Heart is a pump, it's a muscular organ about the size of a fist and is located slightly left of centre in the chest.

*Heart is divided into the right and left side. The division protects oxygen-rich blood from mixing with the oxygen-poor blood.

*Together the heart and blood vessels comprise the cardiovascular system, which circulates blood and oxygen around the body.

*The heart pumps about five quarts of blood every minute and it beats about 100,000 times in a day that's about 35 million times a year.

The body of an essay should contain all the working of the heart and the cardiovascular system in detail. Following are fa ew points that can be used.

*Oxygen poor blood, blue blood, returns to the heart after circulating through the body.

*The right side of the heart composed of the right atrium and ventricle collects and pumps the blood to the lungs through the pulmonary arteries. The lungs refresh the blood with a new supply of oxygen making it turn red. Oxygen-rich blood, red blood then enters the left side of the heart composed of the left atrium and ventricle and is pumped through the aorta through the body to supply tissues with oxygen for valves within the heart keep the blood moving the right way.

*The tricuspid, mitral, pulmonary and aortic valves work like gates on q fence. They open only one way and only when pushed on. Each valve opens and closes once per heartbeat or about once every second.

*A beating heart contracts and relaxes. Contraction is called systole and relaxing is called diastole.

*During systole, the ventricles contract forcing blood into the vessel going to the lungs and body. The right ventricle contracts a little bit before the left ventricle does. The ventricles then relax during diastole and are filled with blood coming from the upper chambers, the left and right atria them the cycle starts over again.

*The heart is nourished by blood to blood vessels called coronary arteries extend over the surface of the heart and branch into smaller capillaries.

*The heart also has electrical wiring which keeps it beating. Electrical impulses begin high in the right atrium and travel through specialised pathways to the ventricles delivering the signal to pump.

The last paragraph should be a concluding paragraph and should contain overall knowledge and result of working of the heart. Following points can be used for the conclusion.

*The condiction system keeps the heart beating in a coordinated and normal rhythm which in turn keeps blood circulating. The continuous exchange of oxygen-rich blood with oxygen-poor blood is what keeps humans alive.