One of the prior
purposes of the organ named as heart in a human body is to pump oxygen, i.e. the fresh new
blood throughout the body. So that, the organs, tissues and the cells can maintain their
existence and function properly.
A point of vital importance in this event is the oxygenated blood is provided and
carried out by two types of circulation; the systematic circulation and the pulmonary
circulation. The oxygenated blood is used mostly by the brain. Because, the functioning of
the brain can endure a deoxygenated environment only for a few seconds.
Anatomically, the heart is divided into four parts, two of them are small, upper
atriums which convey the blood; and the other two are the lower ventricles that carry on
the pumping function. The newly oxygenated blood is pumped around the body via the
arteries, whereas the deoxygenated blood is carried by the veins. The following verse of
the Quran also points out this matter as
follows: We are even closer to you than your aorta.
The main arteries and veins are joined and united with many branches of smaller
blood vessels and capillaries, arteriole and venule, which are located in the limbs of the
body. Moreover, they carry the oxygenated
blood, as well as conveying the deoxygenated blood. In some parts of the body, there are
packages of vein systems available as centers
for collection.
Deoxygenated blood, flowing from the right atrium to the right ventricle through
the tricuspid valve, is carried to the lungs via truncus pulmonalis, the main arterial
trunk. Developing into the aorta and pulmonary artery, truncus pulmonaris carries the
deoxygenated blood to the alveolar capillaries of the lungs where the gaseous exchange
takes place. The oxygen that enters the lungs with each breath, passes through the alveolar walls and cleans the
blood. Newly oxygenated blood then passes into small veins leading to the pulmonary veins,
which leave the lungs and return blood to the left atrium of the heart. Then the blood
flows from the left atrium passing through the mitral valve to the left ventricle, so that
the blood can be pumped around the body. The pumping,which becomes apparent to us as a
pulsation, circulates the blood around the body via aorta, the main artery of the body
coming out from the heart.
During the exchange between the arteriole and the venule located in the limbs,
the deoxygenated blood passes to the veins. The oxygen is carried to the tissues by the
aorta and the deoxygenated blood, collected from the various parts of the body, is
conveyed into the right atrium via the superior vena cava. The deoxygenated blood again
flows into the right ventricle through the tricuspid valve and then joins the pulmonary circulation. All this system repeats
itself during every inhalation and heart beat. Thus, the oxygen is carried to all the
organs and the tissues of the body, primarily to the brain.
