Blood, Veins, and Arteries

Blood, Veins, and Arteries
In what way are veins really blue?
People’s skin tone distorts vein color, as it absorbs blue light. “Subcutaneous fat only allows blue light to penetrate skin all the way to veins, so this is the color that is reflected back. Less energetic, warmer colors are absorbed by skin before they can travel that far” (Helmenstine). In other words, the skin filtrates light wavelengths differently and blue and red light have different wavelengths. Not only that, but veins appearing blue has to do with the way the eyes and brain interprets the information. The brain compares the dark red color of blood to the warm color of skin, making the veins seem blue or green-blue.

In what way are veins not really blue?
Veins seem blue-colored due to light wavelengths being filtered differently by the skin. However, veins are never blue inside the human body, and neither is blood. If blood is never blue and is in fact red, and since blood flows through the veins to get back to the heart, veins cannot be, and never actually are, blue.

Is blood ever blue?
At no point is the blood in human body blue, it is in fact, always red. Human blood is red because it contains a large quantity of red blood cells. These red blood cells have hemoglobin, which is a red-colored protein that carries oxygen to the tissues from the lungs, changes oxygen into carbon dioxide, and bring the carbon dioxide back to the lungs. Hemoglobin that contains oxygen has a bright red color and hemoglobin that lacks oxygen is dark red.

Why is representing veins as blue a good analogy for what a vein really is?
Veins bring deoxygenated blood from different areas of the body to the heart, and deoxygenated blood is not wanted, and since blue is almost the opposite color of red, it is a good analogy.

Why is red a good analogy for a healthy artery?
Red is a good analogy for a healthy artery because healthy arteries should be a bright red color. A bright red color means that the blood...