Blood Vessels. Blood Vessel are tubes which carry blood. Veins are blood vessels which carry blood from the body back to the heart. Arteries are blood vessels which carry blood from the heart to the body. There are also microscopic blood vessels which connect arteries and veins together called capillaries.There are a few main blood vessels which connect to different chambers of the heart. The aorta is the largest artery in our body.lood Vessels. Blood Vessel are tubes which carry blood. Veins are blood vessels which carry blood from the body back to the heart. Arteries are blood vessels which carry blood from the heart to the body. There are also microscopic blood vessels which connect arteries and veins together called capillaries.
Skin pigmentation. Melanin, whose primary function is in pigmentation, has many more important functions to perform in the human body. Protection from UV radiation. Melanin functions as a sunscreen and as a broad spectrum sun radiation absorbent. The absorbed energy causes redox reactions, and both eumelanin and pheomelanin form free radical species. Eumelanin, being more photostable scavenges the originated oxidative species and neutralizes them.
Melanin, the pigment in our skin, can act as a natural sunscreen. People have different skin colors based on where their ancestors originated. Those from warmer, sunnier climates close to the equator have darker skin, because they needed a large amount of melanin to protect them from their sunny environment.