The circulatory system of any animal organism consists of a group of organs that take part in the process of blood circulation. As a result of its normal functioning, the right amount of oxygen and nutrients, hormones and salts, as well as other vital elements, are transferred. In addition, the circulatory system performs a second function. It takes away the waste of cell metabolism and carries away from all parts of the body the carbon dioxide formed in it. A complex network through which the substances necessary for the functioning of the body are delivered to all its systems is formed from blood vessels, the heart and blood itself.
The work of the system that delivers nutrients to all organs is based on the activity of the myocardial muscle. It is she who, performing the function of a pump, pumps blood at a high speed. The value of this value is eleven meters per second. With contractions of the heart muscle in the fluid, a pressure called excess occurs. It exceeds atmospheric. Excessive stress in medical practice is called arterial. Its measurement begins with a set zero value equal to atmospheric pressure. Within one minute of work performed in a calm state of the body, the heart pumps almost 3.6 liters of blood through itself in order to maintain the created internal tension. Blood pressure takes its maximum value at that moment, when the contraction occurs (systole). With relaxation of the myocardium (diastole), the internal tension drops to zero.
The circulatory system through its network passes the bloodstream. It passes through the vessels, representing a liquid having a density of 1.06 grams per cubic centimeter. The bloodstream moves through a system that includes arteries and large veins. These vessels branch out many times and gradually decrease in size to small capillaries. The bloodstream moves at a speed that is set by the heart rate. The movement of fluid is also affected by internal stress and the diameter of the lumen of the vessels. Arteries flow through themselves at a speed of fifty centimeters per second. In the veins, its value is twenty cm / s. Capillaries have the lowest speed due to their small diameter. It does not exceed two millimeters per second. In this case, pulse oscillations in the capillaries are suppressed.
The volume of the circulatory system far exceeds the amount in the body's blood. It is only one forty thousandth full. This has its own reason. In the event of circumstances that require a large flow of blood to the organs, it will move in the right direction.
Anatomy of the heart and blood vessels allows you to constantly ply blood in a triangle that includes the lungs, myocardial muscle and liver. In this case, the necessary nutrients, passing through the arteries and capillaries and getting into every cell of the human body, contribute to the normal functioning of the body. When pathological phenomena are formed in the heart muscle and blood vessels, diseases of the circulatory system occur . These ailments include:
- acute rheumatic fever ;
- coronary heart disease;
- ailments accompanied by an increase in blood pressure;
- rheumatic chronic heart disease;
- violation of pulmonary circulation of blood;
- cerebrovascular disease;
- diseases of capillaries and arteries;
- ailments of veins, lymphatic vessels and nodes;
- other diseases of blood vessels and heart.
The circulatory system, as well as its health, is under the scrutiny of medical science. The reason for this is the disappointing statistics, which put heart and blood vessel diseases in first place in the world in terms of mortality.