Discover the THREE LAYERS of the HEART

The heart is one of the vital organs of the human body. The heart is the main organ of the circulatory system and is considered by many to be the core of the body. human body since, when they stop working, the basic functions of the human body begin to fail within a few minutes. To function properly, the heart is made up of a series of cells and tissues that are arranged in different concentric layers. In this lesson from a TEACHER we will review the three layers of the heart: endocardium, myocardium and pericardium, its main features and how they work. If you want to know more, we invite you to continue reading!

Index

1. The heart: structure and layers
2. Endocardium, one of the layers of the heart
3. Myocardium
4. Pericardium, another layer of the heart

The heart is a muscular organ that, in birds and mammals (including man), it has four cameras: two atria and two ventricles. Therefore, the heart is said to be a hollow muscular organ. Furthermore, despite its important function in the human body, it is about the size of a fist and

To pump blood, the heart has a great contraction force it must push blood from the center of the chest, where it is, to places as far away as the tips of the toes. If it fails, the blood would be retained at one point and there would be an accumulation similar to when we bend a hose through which water circulates. So that the heart can contract but, at the same time, be elastic enough to return to its initial situation and not deform, this organ is made up of three layers with different functions and characteristics: the endocardium, the myocardium and the pericardium.

In this other lesson we will discover all the parts of the heart and their functions.

Image: Lifeder

The endocardium is a delicate membrane found inside the heart and cover the chambers of the heart: atria and ventricles. In turn, the endocardium is made up of five layers: endothelial layer (innermost), inner connective tissue layer, layer smooth muscle tissue, outer connective tissue layer and subendocardial layer (outermost and closely related to the myocardium).

The role of the custodian is monitor myocardial function, the muscular layer of the heart that we will see next. In addition, it also intervenes in the development of the heart during the embryonic stage but also during the adult stage. In addition, it also helps to maintain the electrophysiologically correct and conducive environment for cardiomyocytes to be contractile. In addition, they also create a barrier between the heart and the blood, controlling the ionic composition of the fluid that bathes the kradiomyocytes.

Image: Heart Structure

The myocardium is the middle layer of the heart and she is in charge of produce and maintain contraction of the heart during the cardiac cycle (contractions and strains of the heart). Due to its function, the myocardium is, along with the brain, one of the body regions that consumes more energy, so it has many blood vessels. In addition, the myocardium has a number of very special characteristics:

• It is excitable. The myocardium is one of the few tissues that is excitable, that is, its cells are capable of receiving and reacting to a stimulus (action potential). This property is also held by neurons.
• It is autonomous. The myocardium is an autonomous muscle, that is, it is the cells of the myocardium itself that generate the electrical impulse that leads to its contraction. The generation of this electrical impulse can be modified by factors external to the heart such as hormones. In fact, if we isolate the heart from the body and put it in a saline solution that allows it to remain, but that does not generate external stimuli, the heart will continue to beat autonomously and following a rhythm suitable.
• It is capable of conducting impulses. Cells in a region of the heart, called the sinoatrial node, located above the right atrium, produce the electrical impulses responsible for the contraction of the heart and myocardial cells are capable of transmitting this impulse to the entire organ.
• It is able to contract and relax. The myocardium, upon arrival of the electrical impulse generated in the sinoatrial node (pacemaker), is able to overcome the resistance exerted by the chambers and blood vessels of the heart and contract, emptying out. Once the electrical impulse has passed, the contraction force ceases and the resistance force of the chambers and blood vessels gains and the heart fills with blood again.

Image: SlideShare

The pericardium is a set of two layers of heart that cover the myocardium externally: serous pericardium and fibrous pericardium.

• The serous pericardium It is the innermost layer of the pericardium and is in contact with the myocardium. The serous pericardium can be divided into two layers, a visceral (epicardium) and a parietal, separated by a chamber (pericardial cavity).
• The fibrous pericardium It is the outermost layer of the pericardium. It is basically a bag that covers the heart and whose fundamental function is to protect it, limit its distension and join it to nearby structures. The fibrous pericardium is attached to: the diaphragm, at its base and to the sternum, by means of a ligament, in the ventral part. This allows it to stay in position within the chest cavity.

Image: DocPlayer

If you want to read more articles similar to Layers of the heart, we recommend that you enter our category of biology.

• Aaronson, P.I., Ward, J.P. & Connolly, M.J. (2012) The cardiovascular system at a glance. John Wiley & Sons.
• Endocardium (s.f). On Wikipedia. Retrieved on May 22, 2019 from https://es.m.wikipedia.org/wiki/Endocardio
• Myocardium (s.f). On Wikipedia. Retrieved on May 22, 2019 from https://es.m.wikipedia.org/wiki/Miocardio
• Pericardium. (s.f). On Wikipedia. Retrieved on May 22, 2019 from https://es.m.wikipedia.org/wiki/Pericardio