Blood tests - Blood chemistry or biohumoral tests

The blood analysis are a series of tests which are prescribed to investigate our state of health. The classic blood test consists in blood sampling of a small amount of blood (one or more test tubes), which is then analyzed in detail laboratory techniques and is used to dose one or more substances circulating in the blood, of which we want to know the values.

L'blood analysis it is probably the most requested exam in the world, as it is easy to perform, is not very painful and minimally invasive, and allows you to understand the functionality of most of the various organs and systems.

The blood splits into one part liquid and in a solid part o corpusculate.

There liquid part of the blood is defined:

  • plasma, when we talk about the liquid also containing all the circulating proteins
  • serum, when we speak only of the liquid part without the protein component of coagulation factors such as fibrinogen, prothrombin or factor X, factor VIII and factor V.

There corpuscular part blood includes:

  • Red blood cells, they are also called red blood cells or erythrocytes, and are the main carriers of oxygen to body tissues, thanks to the macromolecule they contain, thehemoglobin.
  • White blood cells, are those responsible for the defense against threats to our body, and are divided into:
    • Neutrophil granulocytes
    • Eosinophilic granulocytes
    • Basophilic granulocytes
    • T lymphocytes
    • B lymphocytes
    • Monocytes and macrophages
  • Platelets, or thrombocytes, are fragments of larger cells (megakaryocytes) that serve, together with the formation of the clot, to block the loss of blood secondary to injury to body tissues, thanks to the creation of a platelet plug.

The blood besides the circulating cells it contains a series of substances such as proteins (enzymes, hormones), fats or lipids, sugars or carbohydrates, mineral salts, vitamins, trace elements.

Generally, blood sampling takes place via the puncture of a vein at the level of the upper limbs (arms), usually in the crook of the elbow (usually the basilica vein) or in veins at the level offorearm or the but no.

The withdrawal is usually done with the so-called butterfly, a small needle with two "wings" that serve to make the handle more manageable, which connects to a "shirt“, A small tube that contains a needle into which the various laboratory test tubes are threaded one by one. The butterfly and the shirt come immediately removed at the end of the withdrawal.

In other cases, when you want to leave a venous access available for future use (e.g. for a person hospitalized), the blood sample is taken with aneedle cannula, that is, with a metal needle, which serves to puncture the vein and which is immediately removed, covered by a plastic cannulainstead, which remains in place within the vein once the needle has been removed. This procedure therefore leaves a peripheral venous access, from which it will be possible to make infusions of drugs and liquids.

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