PATHOLOGY

Detailed explanation-1: -It’s bright red when the arteries carry it in its oxygen-rich state throughout the body. And it’s still red, but darker now, when it rushes home to the heart through the veins.

Detailed explanation-2: -Blood that has been oxygenated (mostly flowing through the arteries) is bright red and blood that has lost its oxygen (mostly flowing through the veins) is dark red. Anyone who has donated blood or had their blood drawn by a nurse can attest that deoxygenated blood is dark red and not blue.

Detailed explanation-3: -RBCs contain hemoglobin (pronounced: HEE-muh-glow-bin), a protein that carries oxygen. Blood gets its bright red color when hemoglobin picks up oxygen in the lungs. As the blood travels through the body, the hemoglobin releases oxygen to the different body parts.

Detailed explanation-4: -The color of human blood ranges from bright red when oxygenated to a darker red when deoxygenated. It owes its color to hemoglobin, to which oxygen binds.