In fact, our veins are not green, but more whitish. We see them as green because of the optical phenomenon resulting from the mixture between the color of blood and that of our skin. The thing happens like this: the blood that passes through the veins is rich in carbon dioxide (CO2) – it doesn’t hurt to remember, the veins take the blood from the organs back to the heart, while the arteries carry the blood rich in oxygen from the heart to the heart. rest of the body. It turns out that the high concentration of CO2 gives the blood a darker red tone. It is the combination of this tone of venous blood with the yellowness of the fat layer of the body and skin that gives the visual sensation that the veins are green. See below for other curiosities about these blood vessels and some differences between them and arteries. 🙂
RED I WANT YOU GREEN
The greenish tone of the veins is due to the mixture of colors reflected by the blood and the skin.
When light falls on blood, all colors of the light spectrum are absorbed by this liquid, except red, which causes it to have that hue to the naked eye. The skin and fat layer of the body have a yellowish hue. Located between our eyes and blood, they act as a filter for blood red, making the remaining color of the spectrum to be green.
UNDERGROUND RIVERS
Unlike veins, arteries cannot be seen with the naked eye as they are located deeper under the skin.
CALIBER ISSUE
In general, as veins have more flaccid walls, and hence dilate more, in the same region of the body they have a larger caliber than arteries. The femoral artery, for example, is 8 mm in diameter, while the corresponding vein measures 10 mm.
WALL AGAINST WALL
The walls of veins are much thinner and flaccid than those of arteries. This is because venous blood does not flow with the same pressure as it travels through the arteries, which rush out of the heart.
WAY WITHOUT RETURN
Most veins, especially those in the arms and legs, have one-way valves called venous valves. Its function is to prevent the backflow of blood caused by the force of gravity. They open for blood to pass through and then close, preventing its return.