Why Rudolph’s Nose is Red

Reinsdyr og jenta på ski

Using a new measuring device, scientists from Amsterdam and the Arctic city of Tromsø has discovered why the reindeer Rudolph has a red nose.

The scientific article is written in connection with British Medical Journal’s Christmas number, and was published on BMJ’s website on Monday.


 If you always have wondered why Rudolph’s nose is red, you should read the abstract of the study:

Objective To characterise the functional morphology of the nasal microcirculation in humans in comparison with reindeer as a means of testing the hypothesis that the luminous red nose of Rudolph, one of the most well known reindeer pulling Santa Claus’s sleigh, is due to the presence of a highly dense and rich nasal microcirculation.

Design Observational study.

Setting Tromsø, Norway (near the North Pole), and Amsterdam, the Netherlands.

Participants Five healthy human volunteers, two adult reindeer, and a patient with grade 3 nasal polyposis.

Main outcome measures Architecture of the microvasculature of the nasal septal mucosa and head of the inferior turbinates, kinetics of red blood cells, and real time reactivity of the microcirculation to topical medicines.

Results Similarities between human and reindeer nasal microcirculation were uncovered. Hairpin-like capillaries in the reindeers’ nasal septal mucosa were rich in red blood cells, with a perfused vessel density of 20 (SD 0.7) mm/mm2. Scattered crypt or gland-like structures surrounded by capillaries containing flowing red blood cells were found in human and reindeer noses. In a healthy volunteer, nasal microvascular reactivity was demonstrated by the application of a local anaesthetic with vasoconstrictor activity, which resulted in direct cessation of capillary blood flow. Abnormal microvasculature was observed in the patient with nasal polyposis.

Conclusions The nasal microcirculation of reindeer is richly vascularised, with a vascular density 25% higher than that in humans. These results highlight the intrinsic physiological properties of Rudolph’s legendary luminous red nose, which help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeer’s brain, factors essential for flying reindeer pulling Santa Claus’s sleigh under extreme temperatures.

If you don’t remember the lyrics – watch this video and sing along!

Text by: Thor Bugge Lanesskog, ThorNews

Photo on top by: Anette Broteng Christiansen, ThorNews, bottom photo by: British Medical Journal

Source: British Medical Journal, Norwegian Broadcasting Corporation

Categories: Quirky

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