THE HEART

Structure of the Heart

The heart is a muscular organ located just to the left of the breast bone
(sternum). It is about the size of your fist, and this amazing muscle pumps
4300 gallons of blood a day. The heart has four chambers:
 

• Atria. The top two chambers that receive blood from the body

• or lungs.

• Ventricles. The bottom two chambers. The right ventricle pumps

• blood to the lungs to pick up oxygen, The left ventricle pumps blood to the rest of the body and is the strongest chamber.

• Valves. There are four valves in the heart that help to direct blood flow. As they open and close, the valves produce sounds that can be heard with a stethoscope. The heart sounds can often tell your doctor about your hearts function.

Function of the Heart

Every cell in your body needs oxygen in order to live and function. The role
of the heart is to deliver the oxygen-rich blood to every cell in the body.
The arteries are the passageways through which the blood is delivered.
The largest artery is the aorta, which branches off the heart and then
divides into many smaller arteries. The veins carry the deoxygenated blood
back to the lungs to pick up more oxygen, and then back to the heart once
again. Blood flows continuously through the circulatory system, and the
heart muscle is the pump which makes it all possible!

Coronary Arteries

Your heart, just like all other muscles in the body, needs its own supply of
oxygen in order to function properly. Although its chambers contain blood,
the heart receives no nourishment from the blood inside the chambers.
The heart gets its blood supply from the coronary arteries. The two major
coronary arteries (the right coronary artery and the left main coronary
artery) branch off the aorta, and then divide into many smaller arteries
that lie in the heart muscle and feed the heart.