If you close your fist tightly, you could figure out the size of this muscular organ. The heart is located just behind and slightly left of the breastbone. Being the core of the circulatory system, it pumps blood through our entire body via arteries and veins.
In humans, along with other mammals and birds, this organ is divided into 4 chambers:
- Right atrium - receiving blood from the veins and pumping it to the right ventricle.
- Right ventricle - receiving blood from right atrium and pumping it to the lungs to get it oxygenated.
- Left atrium - receiving oxygenated blood from the lungs and pumping it to the left ventricle.
- Left ventricle - pumping oxygenated blood to the rest of the body; it is known as the strongest chamber as it contracts vigorously to create blood pressure.
Over the surface of the heart, there are coronary arteries that provide oxygenated blood to the muscle itself. Along with this, there is a web of nerve tissue running through the heart that gives it signals to contract and relax. And, surrounding the heart, there is a protective sac named pericardium that contains a small amount of fluid.
Structure of Human Heart
Given below is a detailed heart diagram. Observe each section carefully and try to remember the names. Along with an unlabeled diagram, we have also provided information of different functions of these parts.
Heart is essentially a muscle that expands and contracts continuously and we call it pumping. The primary function of the heart is to pump oxygen rich blood throughout the body. It beats for 72 times per minute. It is situated between the lungs in the chest cavity and weighs around 10 to 15 ounces.
The heart wall consists of three layers known as epicardium, myocardium and endocardium. Epicardium is the outer layer, myocardium is the middle layer, and endocardium is the innermost layer. Myocardium makes up for the bulk of the heart and is responsible for the pumping and beating of the heart.
Atria and Ventricles
As you can see in the diagram of the heart, that heart is divided in four chambers, namely, right atrium, left atrium, right ventricle and left ventricle. Each of the chambers is separated by a muscle wall known as Septum. The left side of the heart receives oxygen rich blood from the lungs and pumps it out the whole body. The right side of the heart receives deoxygenated blood from the body that is sent to the lungs to purify.
A valve connects each atrium to the ventricle below. The mitral valve connects the left atrium with the left ventricle and tricuspid valve connects right atrium with right ventricle. Apart from this, there are two more valves, known as pulmonary valves and aortic valves. Pulmonary valve separates the right ventricle from the left pulmonary artery. And aortic valve separates left ventricle from the aorta.
Blood Vessels and Blood Veins
Blood vessels play a major role in carrying purified blood from the heart to the rest of the body. They are connected to the upper half of the heart. Aorta is one of the largest blood vessels that carries purified nutrient rich blood away from the body. The left and right pulmonary arteries take the oxygen depleted blood from heart to the lungs. The superior vena cava and inferior vena cava are the two main veins that carry blood back to the heart. The veins generally carry the deoxygenated blood to the heart but pulmonary vein is an exception as it carries oxygenated blood from lungs to the left side of the heart. On the other hand, arteries carry purified blood to the rest of the body but pulmonary artery is the exception. It carries deoxygenated blood from the right side of the heart to the lungs for purification.
From the above information it is clear how crucial the heart is so it is important for everyone to pay attention to the heart health to avoid any kind of heart diseases.
Now you know how complicated yet very smooth is the design of the heart. We hope this diagram helped you understand the structure of the heart well. Now there is a small exercise for you. Given below is the same diagram that you need to observe carefully. The diagram is provided with blank spaces that you need to fill in with right names. Instead of copying from the above labeled diagram of the human heart, try to recall the names and fill in the blanks. As you fill in the blank also try to recall the function of that part. This would be a fun activity for you that would help you learn about the heart in a profound manner.
Holding the left mouse button, drag and drop the image on to your desktop. Later on, once you have properly studied the diagram, you can label this one.
We hope you enjoyed working on the above heart diagrams. Now the next time you go the school, surprise your teacher and classmates with your knowledge about heart and its structure. All the best!