Blood in the human body performs many functions, it protects us, transfers nutrients and oxygen to tissues, and carbon dioxide carries away from them. Arterial is called blood, which contains oxygen, and it is also called oxygenated. The addition of this gas, so necessary to the body, occurs to erythrocytes, which contain molecules of a specific protein, gemma, which contains iron. Anatomists have long proven that arterial blood flows in the arteries, and then, giving oxygen, it becomes venous and flows through the veins.
Arteries and their functions
Arteries are the vessels in which arterial blood flows. And they carry it only from the heart. The largest vessel of the human body, in which blood flows rich in oxygen, is the aorta, in an adult healthy person its diameter is up to 2.5 centimeters. Small arteries can reach only 0.1 millimeter. Immediately near the branch from the heart, the aorta is rich in elastic fibers, they soften the pulse wave that the heart gives, and the arterial blood flows evenly over the vessels. Due to this, oxygen gradually passes into the tissues. Further, the walls of the vessels become less elastic and acquire more density, primarily due to the presence of muscle fibers. Arteries are connected to other arteries, this is called collaterals, due to them, when one vessel is clogged, blood can go differently. Each organ of the human body is constantly waiting for oxygen, which is so necessary in the processes of energy metabolism. The main function of arteries is to deliver blood to them in the shortest possible time. In erythrocytes, there is a lot of oxygen, so the color of the arterial blood is bright red, and in the cut of the vessels it beats the fountain, primarily due to the pressure that is in them.
Almost invisible, but so necessary
All the mystery of the transition of oxygen into tissues is carried out in capillaries, these are the finest vessels, where oxygen is exchanged for carbon dioxide. If the body is OK, the capillaries are not visible, and in case of pathology, a capillary mesh may appear. The length of the capillary is no more than a millimeter, and its lumen is such that it transmits only one red blood cell each. The body has a huge number of such vessels, they are called the capillary network.
What happens to oxygen in the tissues?
In the body, oxygen takes part primarily in the processes of mitochondrial oxidation. During this, transformation of organic substances takes place, and as a result, energy is formed, called ATP (adenosine triphosphate), this substance is the universal and the only energy source. Carbon dioxide, which in the process of metabolism formed in the tissues, getting into the blood, makes it venous. Such blood flows through the veins, and getting into the lungs, carbon dioxide is excreted from the body into the environment.
Arterial and venous
Unequivocally, it can not be said that arterial blood flows in the arteries, and in the veins - the venous blood. Indeed, arterial blood flows through the arteries from the heart. But this is only in relation to a large range of blood circulation, but in a small one everything is quite the opposite. Arterial blood flows in the pulmonary veins. Why in the veins? It's very simple, because the veins are the vessels that carry the blood to the heart, but the arteries from it. Venous blood flows in the arteries of the small circle.
Gas composition
In order to understand how easy the lungs perform their functions, and how much oxygen contains arterial blood, determine the gas composition. The acid-base balance indicator will provide additional information that will reveal the secrets of kidney function or the presence of an infectious process in the body. The analysis for the gas composition will adequately and efficiently select oxygen or oxygen therapy.
Before analysis
Before determining the gas composition of human blood , it is necessary to conduct the Allen test. It will allow us to understand what the functional state of the circulatory system is at the moment . Its essence is very simple and consists in the fact that the subject must clamp the ulnar or radial arteries located in the area of the wrist. Do this until the hand, or rather the palm, becomes pale. Next is to release the blood vessels, the blood circulation will recover, and the palm should become pink or red for no more than five seconds. Then you can determine the gas composition, the blood for this is taken from the vein. The degree of saturation of hemoglobin with oxygen depends on body temperature, acid-base balance, partial pressure of carbon dioxide. If the partial pressure falls below the 60 millimeters of mercury column, one can judge the decrease in the saturation of red blood cells with oxygen. After that it is necessary to stop the bleeding, for this purpose tightly press the cotton or apply bandage, which is removed no earlier than in 30-60 minutes.