By nashemutelu runs more than 90,000 kilometers of blood vessels, transporting primerno4.5-5.5 liter of blood.
Nevralgicheskimtsentrom this wonderful system is the heart - a vital myshechnyyorgan continuously pumping oxygenated blood to normalnoyzhiznedeyatelnosti cells.This is a very important system, because all the power kletokzavisit from its correct working.
How tolkoproiskhodit supply of nutrients to the cells, the blood returns to the heart of the feedback, the entrance to it on the top and bottom of the hollow veins.Then satiated vlegkuyu oxygen, blood continues to move through the body.
Interesting facts about circulation
- movement of blood through the heart lasts 4 seconds.
- blood circulation to the lower konechnostyamzatrachivaetsya about 18 seconds, and the brain - about 8 seconds.
- committed daily around 3000 krugovkrovoobrascheniya.
- length of our blood sosudovsostavlyaet more than 90,000 km.This means that they could wrap zemnoyshar more than two times.
- density of capillari
arteries - the vessels that are responsible for kletochnuyuzhiznedeyatelnost
Polucheniekletkami all necessary nutrients depends entirely on normalnogokrovoobrascheniya.And that is the artery responsible for the delivery of these pitatelnyhkomponentov.In that case, if the delivery of nutrients begin glitches cells uncomfortable, forced to search for yield iznepredvidennyh circumstances.For the first time, they can continue to work vypolneniesvoey despite irregular blood flow.But of course, this estpredel.Basically artery transported minerals, enzymes, vitamins, sugars, fats and oxygen, i.e. the basic components necessary dlyanormalnoy vital functions of all cells in the body.
force of attraction
Bolshuyuchast time we spend sitting or standing, and very rarely lie face down.Poetomuosnovnym obstacle is overcome veins returning blood to the heart, it is the force of attraction.
Arteriyamgorazdo easier to carry out their work, as it is promoted serdechnyesokrascheniya needed to move blood to the body.Veins, on the contrary, the pressure is reduced.
Therefore, to overcome the force of attraction of the venous system should have drugimiresursami.For example, when we run or walk, the pressure exerted napodoshvenny arch (curved part of the sole of the foot), allows podnimatsyapo blood toward the heart.At this time, the agreement provides venoznoypodoshvy, so named because it is an area with a dense network of veins.Eeosnovnuyu function we identified just that - give the first impulse of blood to the last rose to the heart.
With drugoystorony, at the disposal of the venous system, there are other means intended to ensure the correct return of blood to the heart.Bryushnyei calf muscles while reducing the increase in size, putting pressure nabolee deep veins, with whom they come into contact, thereby encouraging krovk heart.
On vnutrenneystorone veins have small valves (there are none in arteries), which napravlyayutkrovotok to heart.Finally, the least important function of breathing, giving impetus to the movement of blood when picked diaphragm to bryushnoypolosti.
deep and superficial venous network
Venoznayasistema consists of a large number of veins of different diameters, distributed povsemu body.
What kasaetsyavenoznoy of the lower extremities of the body (legs), it should be razdelitna two networks.
- Deep network responsible for transportirovkukrovi already omyvshey muscles.Deep vein network is delivered to the heart 90% of the blood.
- Surface network carries 10% of the blood and razvetvlyaetsyav subcutaneous tissue.It is in this network, formed subcutaneously and poverhnostnymivenami typically occurs primarily varicose ven.Polozhitelnym point here is that since poverhnostnayavenoznaya system is not intended for the transportation of a large volume of blood, varicose veins do not present problems for the circulatory system.