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Circulatory system

The work of the circulatory system in the body is one of the most complete and important, since it is in charge of transporting the blood together with the nutrients and oxygen that keep the body functioning. This system is made up of several relevant organs such as the heart, arteries, veins, and blood vessels.

It all starts with the work of the heart, which is in charge of pumping oxygenated blood and with all the necessary nutrients to feed the tissues. Blood begins its journey through the aorta vein, which leaves the heart and branches to the extremities. Throughout the journey there is an exchange of nutrients through the capillary veins that are permeable and flexible, conditioned for this purpose. This process is cyclical, therefore the blood must return to the place of origin to be oxygenated again.

The return occurs from the superior and inferior cava arteries, the superior one comes from the arms and the thorax and the inferior one is in charge of collecting the blood from the feet and legs. Blood returns to the lungs where it is oxygenated again and goes to the heart to be pumped through the body again.

Organs of the circulatory system

The heart

It is the main organ located in the thorax that is responsible for receiving and pumping the blood that circulates through the body . Its composition is muscular and its constant movement, it is formed by four cavities, the right and left atrium and the right and left ventricle. The aorta and vena cava connect to the heart to fulfill the blood cycle.

This organ regulates and controls itself by beating continuously to keep the body and tissues oxygenated. Although the lungs are also involved in the process, the heart is responsible for emitting or propelling the blood.

The aorta

It is the main artery of the human body that collects all the blood that is in the heart or circulates through it to transfer it to the tissues through every corner of the body. In developed adults, this artery reaches up to 2.5 cm in diameter and divides into the descending aorta and the aortic arch.

This artery gives life and origin to all the other arteries in the body with the exception of the pulmonary and also transfers them to the capillaries so that, from there, they supply the oxygen and nutrients required.

In the descent , the so-called aortic arch is formed, which is where it changes direction to go from the heart to the abdomen and becomes the descending aorta that supplies the abdomen, trunk, lymph nodes , stomach and ribs; his work does not end there because it continues to descend to the arms and legs to complete the circulatory cycle.

Superior Vena Cava

To complete the circulatory system, the blood must return to its origin and that is where the vena cava begins its work . It is called superior to the extension of the vein that collects all the blood from the upper part of the body that includes the head, neck, arm and thorax. It reaches the right atrium where it deposits the blood that it transfers so that it begins to be pumped again.

Inferior vena cava

Like its superior pair, it is responsible for collecting all the blood that has already deposited oxygen and nutrients in the body, but this time from the lower organs and extremities. Its journey begins below the abdomen and pelvis to the legs and feet. Back, the blood enters the right atrium after returning from the kidneys . Its measurements can vary depending on where it is located since its thickness can be 30 millimeters or 22 millimeters, being larger towards the most important and remote areas.

The blood

It is a liquid or tissue responsible for transporting nutrients through the veins and arteries , its characteristic red color is given by hemoglobin that combines with the other elements that compose it and in it everything that the body needs to maintain itself is transferred. hydrated mainly using plasma, responsible for transporting water and blood cells.


Like blood, lymph is another colorless fluid that travels through lymphatic vessels throughout the body.

Functions of the circulatory system

  • It transports the oxygen that is generated in the lungs and is injected into the blood throughout the body, this oxygen is necessary for the tissue and cells as well as the organs to function properly, after delivering the oxygen it must collect carbon dioxide and transfer them back to the lungs to be eliminated by breathing. So the circulatory system not only carries blood and nutrients but also eliminates toxins.
  • The distribution of nutrients is also carried out thanks to circulation, the nutrients can be entered through the intake of food, multivitamins or simply a product of the natural physiological and biological processes of the body, the blood receives all this contribution and distributes it according to the areas where they are required.
  • Depending on its work of collecting toxins and promoting their elimination , the waste emitted by the cells of the body is collected and moves them to the kidneys, from there they are processed and eliminated through urine, therefore, although the kidney does not form An exclusive part of the circulatory system also plays a very important role as it is the recipient of these cellular debris.
  • Hormones are not produced throughout the body but they also require transport to fulfill their tasks, which is why in addition to carrying oxygen and nutrients, it also transfers hormones to those most inaccessible places where there are arteries , veins and capillaries. .
  • Protecting the body is also a task shared between the immune system and the circulatory system, because thanks to the blood, leukocytes and antibodies that fight any bacteria can be mobilized, from a skin wound to an infection that has entered the pathways. respiratory It is the most effective and efficient means of transport that the human body has.

Risk factors of the circulatory system

The circulatory system can have natural and chemical enemies that affect its functioning, although there are many diseases associated with this system, the causes are almost always the same and can be classified as follows.

Use of harmful substances

Consuming alcohol and tobacco can put the heart and all the arteries and veins at risk, alcohol works as a vasodilator that makes the heart work irregularly, over time arrhythmias associated with this habit, as well as with smoking, may appear.

An active smoker can increase the risk of having a heart attack by up to six times . In this way, we do not speak of a lower risk but of a real dangerous factor that exposes the heart and arteries to an imminent collapse.

Sedentary lifestyle

Doing nothing can also deplete the circulatory system , because it is with cardiovascular exercise, walking, running, frequent movements, etc., that the heart keeps working in a healthy way. The veins remain elastic and hydrated due to the high demand for fluids that exercise implies.

Bad nutrition

Consuming saturated fats, carbohydrates and starches in excess can affect the blood vessels, obstructing the natural flow of blood, also surrounding the organs with fat and hindering their functions, mainly the heart. A balanced diet can prevent this from happening and, added to constant exercise, keep the body healthy. The causes of heart attack or cardiovascular problems are most often associated with obesity and high body mass indexes .

Circulatory system diseases


This disease occurs when the levels of fat in the arteries are high, it can be due to food intake or sedentary lifestyle and also the high consumption of carbohydrates. The artery becomes inflamed due to the deposit of fat in the endothelium . The disease worsens when ulcers appear in the arteries and rupture forming thrombi, depending on the place where this rupture occurs, it can even be fatal, the most serious area being the brain and the heart.


An inflammation or bulging cavity forms within the artery, which is why the disease is so dangerous. Once this deformation appears, one is at risk of dizziness, weakness, loss of skills such as speech, excessive fatigue and finally death.

The disease worsens when the cavity breaks and there are hemorrhages because depending on the place it can be more or less serious for the person who suffers it. There is no predetermined location for aneurysms to appear.


Also known as CVA or stroke, they are ruptures of the blood vessels in the brain that cause bleeding , this can be of mild magnitude or strong magnitude. Cerebral infarcts can be caused by an interruption of the blood flow in the vessels of the brain but also by a rupture of the same, which complicates the pathology and the clinical picture.

Most of the cases who suffer from this disease are elderly men and women who do not practice physical activities and whose physiological conditions have generally decreased.

Cardiac arrhythmia

It is one of the mildest diseases that the circulatory system can suffer because it only refers to incoordination or heart rhythm problems, in some people it can be faster than usual or slower. Doctors often monitor arrhythmia sufferers for symptoms in case they point to a possible more serious heart attack.

Acute infarction

It is the main disease associated with the circulatory system because it is the one with the highest incidence in many places, it mainly affects elderly men who live under high levels of stress or in unhealthy eating conditions. The accumulation of fat in the coronary arteries or high blood pressure can cause such a sudden stop that the heart stops and that is where the heart attack occurs.

The complete path of blood through the circulatory system

In general terms, it is known that the heart is the beginning of the cycle and also the end, since the blood must return to be pumped back to the body, but what is the cycle that the blood completes to be able to carry everything necessary to the body?

Left Ventricle: Blood begins its journey from the left side of the heart with enough oxygen for all tissues.

Aortic artery: from here it expands throughout the body until branching through the minor arteries and also the capillaries, reaches the extremities and the transfer of nutrients in the skin begins.

Systemic arteries and capillaries: this system, in addition to sharing nutrients, also contains blood that is no longer effective to continue the irrigation process, that is, poor in nutrients and oxygen, therefore, from here they are sent to the veins to start the return to the lungs.

Venas cava: from the superior and inferior vena cava is where the return of blood begins to re-oxygenate.

Right atrium: it is where all the blood returns to be pumped again, its entry is made thanks to the superior vena cava which is the one that connects with the head, trunk, arms and thorax.

Pulmonary arteries: they are responsible for oxygenating the blood in the heart and this process called hematosis involves the pulmonary veins and pulmonary capillary arteries to leave the blood ready for a new cycle of irrigation.

Left ventricle: the blood returns to its point of origin, the left ventricle, from where it begins its journey through the aorta again and fulfills its predefined function.

Finally, it is a complete cycle that involves lungs, heart and veins and from there, it feeds all the needs of the human physiological system.

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Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

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