BMJ-British Medical Journal Summary: Rudolph's nose is red because it is diabetes bmj education supplied with red blood cells which help to protect it from freezing and to regulate brain temperature.
Tiny blood cells known as micro-vessels in the nose are vital for delivering oxygen, controlling inflammation, and regulating temperature, but few studies have assessed their function in detail.
Knowing how important this regulation is for flying reindeer, who have to deal with extremes of temperature while pulling a sleigh, researchers in the Netherlands and Norway set out to test whether Rudolph's infamous red nose was due to "a highly dense and rich nasal microcirculation" compared with human noses.
They also found a high density of mucous glands scattered throughout the reindeer noses, which they say helps "maintain an optimal nasal climate during changing weather conditions and extremes of temperature as well as being responsible for fluid transport and acting as a barrier.
Note: Content may be edited for style and length. Journal Reference: C. Ince, A. Milstein, K. Yuruk, L. Folkow, W. Fokkens, A. Why Rudolph's nose is red: observational study.