The heart is located between the two lungs in the thoracic cavity. The
purpose of the heart is to distribute oxygen and nutrients to all systems by the
pumping blood throughout the body.
main parts of the heart
The heart is composed of the right and left sides which are separated
by a thin muscular wall referred to as the septum. More specifically, the wall
separating the left and right atria (the upper compartments of the heart) are
called the inter-atrial septum separates, while the thick wall separating the
left and right ventricles (the lower compartments of the heart) is called the
inter-ventricular septum. As previously stated, the right and the left sides
consist of an atrium and ventricle. The atrium and ventricles are separated by
thick fibrous tissues called atrio-ventricular septums. The atrium, located
above the ventricle, receives blood from the body and pumps it to the
ventricle. Deoxygenated blood travels through the right side of the heart while
oxygenated blood travels through the left side. The pumping of oxygenated blood
to the bodies various tissues and organs is referred to as systemic
circulation, while the pumping of blood to the lungs is referred to as pulmonary
circulation. The heart muscle is also protected by a double walled membrane.
The superior vena cava, inferior vena cava, pulmonary artery, pulmonary veins, and aorta are referred to as the four great vessels since these are the vessels that directly connect to the heart. There are there main types of blood vessels, including the arteries, capillaries, and veins. Arteries are responsible for carrying blood away from the heart, while veins carry waste and deoxygenated blood back to the heart. The capillaries simply serve as intermediate, connecting arteries and veins.
The superior vena cava, inferior vena cava, pulmonary artery, pulmonary veins, and aorta are referred to as the four great vessels since these are the vessels that directly connect to the heart. There are there main types of blood vessels, including the arteries, capillaries, and veins. Arteries are responsible for carrying blood away from the heart, while veins carry waste and deoxygenated blood back to the heart. The capillaries simply serve as intermediate, connecting arteries and veins.
This video is a useful and easy to understand visual representation of the process of blood circulation.
How the process works
Deoxygenated blood enters the right side of heart by means of the vena cava.
The upper vena cava is referred to as the superior vena cava while the lower
one is referred to as the inferior vena cava. The blood is then pumped from the
right atrium to the right ventricle by passing through the tricuspid valve,
which consists of three muscular flaps that allow for one way movement of blood
from the atrium to the ventricle. Then, the pulmonary artery transfers this
blood from the right ventricle to the lungs. The deoxygenated blood obtains oxygen
from the lungs and returns to the left atrium through the pulmonary veins. Afterwards,
the oxygenated blood is pumped from the left atrium to the left ventricle by
passing through the bicuspid, or mitral, valve. The mitral valve is similar to
the tricuspid value, but is only composed of two muscular flaps rather than
three. Finally, the aorta pumps this oxygen rich blood to the head and rest of
the body.
Interesting Fact
If all the
blood vessels in an average child were laid out in a line, the line would be
over 60,000 miles long. If an adult's vessels were laid out similarly, they
would be almost 100,000 miles long.