What color is oxyhemoglobin, and what color is deoxyhemoglobin?

Oxyhemoglobin is the form of hemoglobin that is bound to oxygen, and it has a bright red color. This vibrant hue is noticeable in arterial blood, which is why blood that is rich in oxygen appears bright red as it flows through the arteries. On the other hand, deoxyhemoglobin is hemoglobin that has released its oxygen. This form appears bluish in color, particularly when viewed through the skin, which is why veins, which carry deoxygenated blood back to the heart, often appear to have a bluish tint. The difference in color between these two forms of hemoglobin is due to structural changes within the hemoglobin molecule that occur when it binds or releases oxygen.

Understanding these color differences is crucial in physiology and helps explain how the body transports oxygen efficiently.