Question

In the diagrams we conventionally show veins in blue.What is the actual colour of the blood following through the following ?
(i) In arteries (ii) In veins (iii) In capillaries

Answer 1

The blood of the humans and the vertebrates are always red in color due to the presence of the pigment hemoglobin, this hemoglobin imparts red color color to the blood through red blood cells. But the color may show a slight variation due to the amount of oxygen in it. The blood colour in different blood vessels are:

(i) In arteries - The color of the blood is bright red due to the presence of an adequate amount of oxygen. This type of blood is called as oxygenated blood.

(ii) In veins - The blood in the vein is deoxygenated blood (lack of oxygen in the blood), due to this condition, the color of the blood is darker in shade. This dark colored blood often seen as bluish or purplish color.

(iii) In capillaries - The blood in the capillaries is oxygenated as well as deoxygenated due to which certain capillaries are bright red in color while others are dark or deoxygenated and seen as bluish or purplish color.