Welcome to Softilmu, a knowledge blog that shares sincere knowledge. This time we will share knowledge about the Heart, some of the main points we will discuss are Definition, Structure, and Function of the Heart.
The heart is a muscular organ that has four chambers located in the chest cavity under the protection of the ribs, slightly to the left of the sternum (breastbone). Its mechanism of action is similar to that of a pump to put pressure on the blood vessels so that blood can always flow in the body. The size of the heart is approximately the size of the right hand grip.
The heart is one of the vital organs that plays an important role in the balance of the hemodynamic system of the human body.
Anatomically there are several parts of the heart that are important for us to know, including:
1. Heart Shape and Size
The heart is the main organ in the cardiovascular system. The heart is formed by muscular organs (muscle), apex (peak) and base cordis (base of the heart), right and left atria and right and left ventricles.
The size of each heart is sequentially length, width, and thickness is 12 cm, 8-9 cm and 6 cm. Approx. heart weight 7-15 ounces or equivalent to 200-425 grams and slightly larger than the right fist. Every day the heart beats 100,000 times and during that period the heart pumps 2000 gallons of blood or the equivalent of 7,571 liters of blood. The position of the heart is located between the two lungspulmonary) and in the center of the chest cavitythorax).
The heart has three layers and each layer has a different function, including:
a. Pericardium, are the membranes that surround the heart which consists of two layers, namely:
  • Parietal pericardium (outer layer attached to the sternum and the lining of the lungs).
  • Visceral pericardium (surface layer of the heart called the epicardium).
  • Between the two layers above, there are 50 cc of pericardial fluid which functions as a lubricant to prevent friction between the pericardium and epicardium arising from the heart’s motion when pumping.

b. Myocardium, is the middle layer (core layer) of the heart and is the thickest and consists of the heart muscle. Its function is to contract the heart;

c. Endocardium, is the outermost layer consisting of endothelial tissue.

The heart consists of four chambers, namely the right atrium (right atrium), the left atrium (left), the right ventricle (right ventricle), and the left ventricle.

The atria are the chambers above the heart and are thin-walled, while the ventricles are the chambers below the heart and have thicker walls because they have to pump blood throughout the body. The following is a function of each of the chambers in the heart:
  • Right atrium serves as a reservoir of low oxygen (O2) blood from the whole body.
  • Left atrium (atrium) It receives oxygen-rich blood from the lungs and carries it to the lungs.
  • Right ventricle (ventricle) It receives blood from the right atrium and pumps it to the lungs.
  • Left ventricle (ventricle) functions to pump oxygen-rich blood (O2) throughout the body.

In each part of the heart, the atria and ventricles are separated by a septum. The two atria are separated by a septum between the atria (septum interariorum), while the two ventricles are separated by a septum between the ventricles (septum inter ventriculorum).

Between the right atrium and right ventricle there is a valve that separates the two, namely the valve (valvula). tricuspidalis, while the left atrium and left ventricle also have valves called valves mitral/ bicuspid. Both of these valves function as a barrier that can open and close when blood enters from the atria to the ventricles.

The tricuspid valve is located between the atrium (atrium) and the right ventricle (ventricle) and consists of three cusps. When this valve is open, blood will flow from the right atrium to the right ventricle. The tricuspid valve prevents the return of blood to the right atrium by closing during contraction of the ventricles.
After the tricuspid valve is closed, blood will flow from the right ventricle through the pulmonary trunk. At the base of the pulmonary trunk, there is a pulmonary valve consisting of three leaflets that open when the right ventricle contracts and closes when the right ventricle relaxes, allowing blood to flow from the right ventricle to the pulmonary artery.
The bicuspid valve is also known as the mitral valve and consists of two cusps. This valve plays a role in regulating blood flow from the left atrium to the left ventricle. Like the tricuspid valve, this valve closes when the ventricles contract.
The aortic valve consists of three cusps located at the base of the aorta. When the left ventricle contracts, this valve opens, allowing blood to flow throughout the body. On the other hand, the valve closes when the left ventricle relaxes, preventing blood from re-entering the left ventricle.
The main function of the heart is to provide oxygen (O2) throughout the body and to rid the body of metabolic products in the form of carbon dioxide (CO2). The heart performs this function by collecting oxygen-depleted blood from the rest of the body and pumping it into the lungs, where it picks up oxygen and removes carbon dioxide (called pulmonary circulation). Then the heart collects oxygen-rich blood from the lungs and pumps it to tissues throughout the body (called the systemic circulation).
During a beat, each heart chamber relaxes and fills the heart with blood (called the diastole period). Instead the heart contracts to empty its contents (called the systole period). The two atria (atria) relax and contract simultaneously, and the two chambers (ventricles) also relax and contract simultaneously to carry out this mechanism.
When doing a contraction, the heart beats “rhythmically”, this is the result of an action potential generated by the activity of the heart itself. This event is caused because the heart has a mechanism to conduct its own generated electricity to contract or pump and relax or is known as the electrical system of the heart. The mechanism of electric current that causes this action is influenced by several types of electrolytes such as K+, Na+, and Ca2+. So that if there is a disturbance in the electrolyte levels in the body, it will also cause disturbances in the mechanism of electricity flow in the human heart.

So that’s the discussion this time with the title Definition, Structure, and Function of the Heart. Hopefully the knowledge can be useful. If there is still something you don’t understand, you can ask it through the comments, we will try to respond quickly and accurately. Thank you for visiting softscience.