Know Your Heart

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Know Your Heart
We all know that Heart is a crucial organ in our
body that constantly and tirelessly pumps blood
to all parts of our body. It starts functioning
at about 6 weeks of Intrauterine Life. From then
it functions continuously till the very end of
life. Normal functioning of every other organ is
dependent on the normal functioning of heart.
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Chambers Of Heart Heart has 4 chambers- two Atria
(atrium-singular) and two Ventricles. The atria
have thinner walls compared to those of
ventricles which are thick and muscular. The
atria receive blood and ventricles pump blood.
The wall that separates left and right atria is
known as Inter Atrial Septum (IAS) and the one
that separate ventricles is called Inter
Ventricular Septum(IVS) Blood Vessels Attached
To Heart Right Atrium has two large veins
bringing blood to it. Superior Vena Cava (SVC)
Major Vessels Of Heart Right Atrium receives
blood from all over the body through two large
veins. Superior Vena Cava (SVC) brings blood from
upper body while Inferior Vena Cava (IVC) drains
the lower body. IVC
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contributes 60 of the blood return. Apart from
this, one major route of blood return is the
Coronary Sinus (CS), which returns blood from the
veins of heart itself. Left Atrium receives pure
blood from the lungs via 4 pulmonary veins. Two
on Right (Right Superior and Inferior pulmonary
veins) and two on the left (Left Superior and
Inferior pulmonary veins). The right ventricle
pumps its blood into large pulmonary Artery while
left ventricle ejects into Aorta- the biggest
artery in the body. Coronary Arteries Heart
muscles too require oxygenated blood, which is
supplied through Coronary arteries which are the
first two branches of aorta. These are Left (LCA)
and Right (RCA) coronary arteries.
The left Coronary Artery after a short broad stem
(Left main artery) divides into two major
branches- Left Anterior Descending Artery (LAD)
which supplies the front of heart and
interventricular Septum (IVS) and Left Circumflex
Artery (LCA) which supplies the lateral and
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posterior part of the left ventricle. Right
Coronary Artery mainly supplies the Right
Ventricle, Inferior (lower) part of the Left
ventricle and part of IVS. How Heart Beats
Regularly? Have you ever wondered what makes our
heart beat so efficiently and regularly? What
decides rhythm of heart? The secret is the
internal pacemaker (timer) and the conducting
system of the heart (Electrical circuit).
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The natural pacemaker is situated at the junction
of Right Atrium and SVC. It is called SA note.
There is a network of special fibres starting
from the pacemaker and going all over the heart
muscles. This is called the conduction system.
The pacemaker is capable of producing regular
stimuli of electrical activity which travels
along the conduction system to the entire heart
making the muscles contract.