Blood system

Blood System : Through this system pass all the nutrients we need for life. But its function is not limited only to transport; It also protects and maintains us at the exact temperature.


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  • 1 Features
  • 2 Arteries, veins and capillaries
    • 1 The arteries
    • 2 The veins
    • 3 The capillaries
  • 3 Source


Just as the water we drink on a daily basis is distributed through an extensive network of pipes until we reach our homes and serve as food, similarly, blood flows through the body through an intricate network of pipes. Our organism, which is made up of millions of cells, needs oxygen and energy- generating substances for its normal functioning . These vital elements are found in the blood, and it is the circulatory system in charge of distributing it throughout the body. In other words, it is a continuous pumping system in a closed circuit, made up of a motor, which is the heart ; the ducts or blood vessels , which are the arteries , veinsand capillaries ; and the fluid that passes through them, the blood . In addition to transporting the nutritional elements, this distribution center performs other primary functions, such as the transport of some hormones, the elimination of the end products of metabolism and the regulation of temperature.

Arteries, veins and capillaries

The system of pipes in our body is made up of blood vessels, which according to their diameter are classified into: arteries, veins and capillaries. Through this structure of large and small conduits, all of our blood circulates over and over again.

The arteries

They are tubes that start from the heart and branch out like a tree trunk does . They have thick and resistant walls made up of three layers: an internal or endothelial layer, a medium with muscular and elastic fibers , and an external one with connective fibers. They carry oxygen-rich blood, and depending on the form they take, or the bone and organ with which they run, they receive different names, such as humeral, renal or coronary, among others.

The veins

Once the blood has discharged the oxygen and collected the carbon dioxide, this fluid begins the journey back to the heart and lungs through the veins. These ducts consist of two layers, one endothelial and the other made up of elastic, muscular and conjunctive fibers. Unlike the arteries, their walls are less elastic, and every certain distance they have valves that prevent the blood from falling under its own weight.


The blood vessels become thinner as they branch out into the body. Formed by a single layer of cells, the endothelial, this network, due to its extreme thinness, facilitates its function of gas exchange between blood and tissues or between blood and air that has penetrated the lungs.

At the entrance of these small tissues there are stripes that stretch or contract to allow or prevent the passage of blood. In the whole body it is estimated that there are more than 60 thousand kilometers of them, being the farthest point of the journey that blood makes , and the place of supply of all tissues and organs, because each of the cells of the body is at less than 0.2 millimeter of a capillary.


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