When talking about the blood circulation, heart is considered to be one of the most important organs. It is responsible for the circulation of blood in our body. The circulatory system in our body consists of systemic circulation and pulmonary circulation.
Systemic circulation is related to the blood flow from the heart to different parts of the body and pulmonary circulation consists of the purification of blood in the lungs.
Hence the heart will come under systemic circulation and to trace the pathway of blood through the heart, we first need to know about various parts of the heart and the organ related to its working.
Various Parts of the Heart
Heart is a four chambered organ which is located slightly left to the chest.
Its size is approximately the size of one's fist. It pumps blood normally 72 times per minute and hence we can hear rhythmic heart beats every time. Let's find out the anatomy of the human heart and its participation in the blood circulation process.
Atrium and Ventricle
Heart is divided into four chambers known as left atrium and right atrium and left ventricles and right ventricles. Atrium are the upper chambers of the heart and the ventricles are the lower chambers of the heart. These chambers are divided by a layer known as septum. Left ventricle is the largest chamber in the heart.
Valves are like the gates which stop the back flow of the blood. There are four valves in the heart known as the pulmonary valve, aortic valve, bicuspid valve and tricuspid valve. These valves facilitate the flow of blood in one direction.
The pulmonary valve helps in stopping the blood flow from the right ventricle to the left pulmonary artery which takes impure blood to the lungs. The aortic valve helps in preventing the pure blood flow from left ventricles to the aorta which further supplies the blood to different parts of the body.
The bicuspid valve separates the left atrium and the left ventricles and the tricuspid valve is present between the right atrium and right ventricles.
The blood vessels are the carrier of blood to different parts of the body. There are two types of blood vessels - arteries and veins. The arteries (except pulmonary artery) carry oxygenated or pure blood from the heart and supply it to different parts of the body.
Whereas veins (except pulmonary veins) carry deoxygenated blood from different parts of the body to the heart for purification or oxygenation. Pulmonary artery carries impure blood from heart to the lungs and pulmonary vein carries pure blood from lungs to the heart.
What is the Pathway of Blood Through the Heart?
Now that you have understood about the various parts of the heart which participate in the circulatory system, let's go further to know about the pathway of blood. The blood is pumped or controlled by the heart using electrical signals which can be seen as contraction and relaxation of heart walls.
Contraction of the heart walls results in the pumping of the blood to different parts of the body. The blood flow can be divided into deoxygenated blood flow and oxygenated blood flow.
Deoxygenated Blood Flow
The blood is carried by veins and small venules from different parts of the body to the major veins known as superior vena cava and inferior vena cava. These major veins carry the blood to the heart. The blood enters the right atrium from the veins and then it is sent to the right ventricle through the tricuspid valve.
The tricuspid valve prevents the back flow of the blood and maintains the direction of the blood flow. Then the blood is sent to the left pulmonary artery through the pulmonary valve where the blood is carried further to the lungs for purification or oxygenation.
Different Parts of the Body → Major Veins → Right Atrium → Right Ventricle → Pulmonary Artery → Lungs
Oxygenated Blood Flow
Now after the purification or the oxygenation of the blood, the blood comes back to the heart for the further process. Oxygenated blood from lungs is brought to the heart by the pulmonary veins. Blood enters the left atrium first and through the bicuspid valve it enters the left ventricle.
Bicuspid valve prevents the back flow of the blood. The left ventricle is the largest and strongest chamber of the heart. It has the capacity to pump the blood to the aorta. The blood from the left ventricles is pumped to the aorta through the aortic valve which prevents the back flow of blood.
Then the aorta further divides into two arteries one goes up and supplies blood to the shoulder and head and the other goes down which supplies blood to the liver, stomach, kidney, genital organs, etc.
Lungs → Pulmonary Veins → Left Atrium → Left Ventricle → Aorta → Different Parts of the Body
The function of heart and its ability to circulate the blood to various parts of the body, makes it one of the most important organs. Any problems in the blood circulation may lead to life-threatening conditions. So, take care and stay healthy!