What is the heart?

The heart is located in the chest, between the lungs and slightly to the left of the breastbone. It is the first body to be formed and begin to exercise its functions. It has four cavities, a muscular wall and two ventricles.

In the work “Anatomy of the heart” by Dr. Paloma Aragoncillo, it is explained how the heart is inside a bag that is called the pericardium, which has an inner and an external leaf. Between them there is a significant amount of fluid (even if it is small), to prevent the heart from rubbing during its beat.

The heart acts as an aspirant and impellant pump and is responsible for correctly propelling blood through its circulation system. In the same way, there are other systems in our bodies that complement its functioning and are: hepatic, gastrointestinal, arterial and lymphatic.

Heart functions

The heart is incredibly complex. Each of its elements work together for the fulfillment of specific and absolutely indispensable functions for our body.

Part of these functions will be described below to further understand the importance of this vital organ.

pump blood throughout the body

The heart works like two pumps, the right side pumps blood to the lungs and the left to the peripheral organs. It is the rhythmic and automatic movements of the heart that allow the ventricles to contract and the contained blood to move to the arteries.

In an article by Rady Childrens, San Diego Hospital, entitled: “Your heart and circulatory system” , they explain that it takes 60 seconds for blood to circulate through each cell in our system, since it needs a constant supply to function properly.

In addition to that, it is also responsible for eliminating waste and detoxifying the body through each lap.

Distribute nutrients and oxygen to all organs

One of the main tasks of the heart is to transport oxygen to the body through the blood, and with this, due to its great reach, it is also responsible for mobilizing nutrients and distributing them in our system. Even hormones are transported this way.

At the Texas Heart Institute , they explain how the blood through a complex network of arteries, arterioles, and capillaries returns to the heart through the venules, and the veins are in charge of this hard work.

Remove waste compounds from the blood

It is then when all the carbon dioxide that has been collected in its journey through the body is discharged into the pulmonary alveoli and through the oxygenation of hemoglobin it is loaded again with blood to return to the heart.

Carry out the cardiac cycle

The cardiac cycle is the one that carries out all electrical and mechanical phenomena, within each of the heartbeats. Each cycle consists of atrial systole and diastole, to move blood from areas of lower to higher pressure.

It also consists of certain phenomena, which are:

  • Atrial systole: flow of blood volume into the ventricles.
  • Ventricular systole: the ventricles contract and the atria relax. They produce the first sound of the heartbeat.
  • Ventricular diastole: the speed of the blood decreases and the aortic and pulmonary valves close. Produces the second sound of the heartbeat.

Release the hormone atrial natriuretic peptide

It’s a venodilator. It is produced, stored, and released by cardiac myocytes from the atria of the heart. And it is important to mention that it is usually a response of the organism to the increase in blood pressure levels.

Likewise, a blood test with a positive BNP (acronym in English for atrial natriuretic peptide hormone), identifies heart failure with 90% certainty, and these are evaluated with values above 100 pg/mL. The greater the heart condition, the higher the numbers obtained.

Parts of the heart and their functions

Each of the parts of the heart has a particular function. Together, they form an indispensable and precise system for our body. All these different structures lead to the proper function of this organ.

Below we mention and explain them with greater emphasis to recognize their importance.

right atrium

According to the research carried out by the Virtual Nurse of Barcelona, entitled:Cardiovascular system: anatomy , it is defined as a narrow, thin-walled cavity that forms the right edge of the heart and receives blood from three vessels.

It is where the blood enters the heart from the vena cava, both inferior and superior. She performs a contractile function and is located specifically to the back and to the right.

In addition to that, it is in charge of sending an electrical signal to start the contraction of the heart muscle. The sinus node is located in the right atrium.

left atrium

The blood that is newly oxygenated on its way through the lungs reaches the left atrium. This atrium is smaller than the right and is the most distant cavity of all those that make up this cardiac muscular organ. In fact it is related to the esophagus and the spine.

It receives blood through the only four pulmonary veins and its inner and outer faces are smooth, this is because the pectineal muscles are only located in the appendage.

Right ventricle

The right ventricle is an elongated, thick-walled cavity that forms the anterior face of the heart. It is separated from the right atrium by a valve called the atrioventricular or tricuspid valve.

According to Dr. Paloma Aragoncillo, the right ventricle has a triangular shape and its surface shows muscles called papillae. These protrude from it and serve as an anchor for a valve called the tricuspid.

Left ventricle

It is longer and narrower than the left. It has a thick wall and tendon cords. It is the largest and strongest chamber of the heart.

It is therefore considered the main chamber and is responsible for driving blood, which will leave through the aortic valve for the aorta with enough force to travel throughout the body.

Tricuspid valve

It is through which blood passes to the right ventricle. It is the atrioventricular valve, but it is known as tricuspid because it has three leaflets or leaves of different sizes.

According to Ivan Sastre and Ricardo Pérez in Anatomy and Physiology of the Heart , the tricuspid valve controls blood flow between the right atrium and the right ventricle.

Mitral valve

It allows oxygen-rich blood from the lungs to pass from the left atrium to the left ventricle. Being a valve, it is important to mention that they are capable of allowing the passage of blood in one direction, but never in the opposite direction.

This valve also has two leaflets, anterior and posterior, and shows two commissures. It is round in shape with a circumference between 90 and 101 mm, which is directed obliquely forwards to the left and then downwards.

sigmoid valve

The aortic sigmoid valve is responsible for regulating the flow of blood to the aortic artery from the left ventricle. The pulmonary sigmoid valve is what prevents blood from returning from the pulmonary artery to the right ventricle.

Both consist of a union zone and compose between them three veils located one after the other. They are pocket-shaped with an opening into the cavity of the pulmonary or aortic artery.

Interatrial Septum

It is in charge of dividing the right and left chambers of the heart. In this septum, approximately 2.5 mm thick, a thin, muscleless, oval-shaped area can be seen as a curtain. The atrioventricular node is located in it.

Septum interventricular

It is approximately 10 mm thick, although at its base there is a thinner fibrous tissue of approximately 2 mm.

In the AnatomyArticle they explain the importance of this septum, being essential in the early diastolic movement, being the one that produces a large part of the ventricular contraction with its structure.

His bundle and Purkinje fibers

The bundle of his are fibers that carry electrical impulses to the center of the heart. Defects that exist with these various components lead to problems with the heartbeat.

Purkinje fibers are myocardial fibers, which conduct the electrical stimuli that intervene in the nervous reaction of the heart, to allow it to contract in the correct and adequate way for its functioning.

Both fibers are conducted at high speeds and are located in the ventricular walls. They are in charge of conducting the electrical impulses that also allow the opening of the valves, in addition to the passage of blood to the only aortic and pulmonary arteries.

Pulmonary arteries

They have an approximate size of 50 mm and are divided into two large trunks, where the blood takes oxygen. They are responsible for transporting deoxygenated blood to the lungs and later mobilize it to the pulmonary veins that carry it to the left atrium.

Aortic artery

It is the main artery that distributes blood throughout the body when diastole occurs. It is approximately 67 mm in circumference and is the largest artery in our entire body, precisely because of the important function it performs.

venas cava

They constitute, in their upper and lower form, the longest veins in the body. InAnatomy and Physiology of the Heart, “ they explain that blood from the head and arms returns to the heart through the superior vena cava, and blood from the lower parts of the body returns through the inferior vena cava.

myocardium, epicardium and endocardium

The endocardium is a membrane that lines the chambers of the heart, and the epicardium is the outermost layer of the heart.

The myocardium is the muscular tissue of the heart made up of a network of muscle fibers linked together.

The endocardium, for its part, is a whitish membrane that covers the internal surface of the heart in its entirety. And, the epicardium, also known as the visceral pericardium, is a fibrous tissue that forms a kind of sac.

Foramen oval

Under this name is known the opening that exists between the auricles of the heart, when we are formed during pregnancy.

It is a hole that allows blood to bypass and bypass the lungs and closes over time after birth.

Papillary Muscle

These cone-shaped muscles located inside the heart ventricles. They are responsible for providing chordae tendineae to the mitral leaflets.

Furthermore they contract during ventricular systole and act as tensors.

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