Photo: Ashley Coombs 
 
 Published: 18 Dec 2012 12:10 GMT+01:00 | Print version 
 
 Updated: 18 Dec 2012 12:10 GMT+01:00 
 
 Rudolph the Red-Nosed Reindeer's snout has been immortalised in movies, books and song. But until now, no-one has offered a scientific explanation for the glow that allows the world's most famous antlered herbivore to guide Santa's sleigh through the night before Christmas. 
 
 In a study released on Monday, researchers in Norway and the Netherlands used a hand-held microscope to examine the nasal lining of five healthy humans, two reindeer and a sixth person with a non-cancerous nasal growth. 
 
 Reindeer noses have 25 percent more blood vessels than human noses, according to the tongue-in-cheek investigation, published by the British Medical Journal (BMJ) in its Christmas edition. 
 
 The tiny blood vessels provide plentiful oxygen-carrying cells and help control the body's temperature, showed their findings, which were backed by an infrared image of a reindeer after exercise. 
 
 "Rudolph's nose is red because it is richly supplied with red blood cells, comprises a highly dense microcirculation, and is anatomically and physiologically adapted for reindeer to carry out their flying duties for Santa Claus," the paper observes. 
 
 VIDEO: Lars Folkow from the Department of Arctic and Marine Biology, University of Tromsø, explains: 
 
 Rudolph's round-the-world feat has been closely scrutinized by physicists. 
 
 In order to deliver presents to children in around 100 million homes where the Santa tradition is observed, he would have to travel at around 1,000 kilometres (650 miles) per second, they estimate. 
 
 At such speeds, the reindeer, Santa and the sleigh would be vaporised by friction with the air, along with the gifts and any little elvish helpers who came along for the ride. 
 
 Rudolph would need to deploy an ion shield to protect them, or exploit loopholes in the space-time continuum so that they travelled between dimensions in order to deliver the presents on time. ||||| A picture is worth 1,000 words, but some videos are worth a second view. Here is an encore video from the past, originally published on December 17, 2012. 
 
 An investigation into the origin of Rudolph the Reindeer's red nose has ended the generations-old debate by uncovering an elusive but long-hypothesized scientific explanation: A snootful of red cells. 
 
 Detailed evaluation of adult reindeer's nasal microcirculation revealed similarities with human nasal microvasculature, but also striking differences. Reindeer nasal microcirculation exhibited a highly vascularized nasal mucosa, a red cell-rich nasal septal mucosa, and a microvessel density 25% greater than that of humans. 
 
 The architecturally distinct nasal microvasculature confers on Rudolph a nose that "is red and well adapted to carrying out his duties in extreme temperatures," as reported online in BMJ. 
 
 "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' sleigh under extreme temperatures," Can Ince, PhD, of Erasmus Medical Center in Rotterdam, the Netherlands, and co-authors wrote in conclusion. 
 
 The findings are consistent with an inherent adaptive mechanism in reindeer vascular development to deal with the cold climate, according to a researcher who was not involved in the study. 
 
 "In colder climates and also when they are higher up in the atmosphere pulling Santa's sleigh, the increase in blood flow in the nose will help keep the surface warm," John Cullen, PhD, of the University of Rochester in New York, told MedPage Today. 
 
 The nasal mucosa, and its associated microcirculation, plays a major role in human health and disease. In the healthy state the nasal microcirculation facilitates the processing of inhaled air (heating, filtering, dehumidifying), control of inflammation, fluid transport for mucous formation, and oxygenation of nasal parenchyma. 
 
 The nasal mucosa also aid drug uptake and response to allergens. 
 
 Despite the physiologic importance of the nasal microvasculature, few studies have examined the microvasculature's function and morphology. To a large extent, the paucity of investigation reflected the lack of suitable instrumentation to conduct studies. 
 
 The evolution of hand-held intravital video microscopes has proved the means for direct visualization of the nasal microcirculation. Availability of the devices has afforded opportunities to study the human nasal microvasculature and to perform comparative studies. 
 
 Ince and colleagues described the use of hand-held vital video microscopy to study the microvasculature of the human nose and compare it with that of the reindeer nose. The study involved five healthy volunteers, one patient with grade 3 nasal polyposis, and two adult reindeer from Tromsø, Norway, which is located near the North Pole. 
 
 By means of the hand-held microscope, investigators obtained high-quality images of the nasal septum and inferior turbinate of the volunteers and the patient with nasal polyposis. Circularly arranged capillaries were seen throughout the nasal mucosa. 
 
 Quantification of nasal microcirculation in the volunteers demonstrated a mean perfused vessel density of 15 mm/mm2 and a microvascular flow index of 3.0 arbitrary units. In the patient with nasal polyposis, nasal microvascular was irregular, and characteristic architectural findings were absent, such as hairpin-like capillaries. 
 
 Investigators examined nasal microvasculature in one of the volunteers after a vasoconstrictor challenge with 100 mg of cocaine, which is routinely used as a local anesthetic and vasoconstrictor by ear, nose, and throat specialists, the authors noted. The challenge resulted in transient cessation of microcirculatory flow. 
 
 "We're kind of glad they didn't do the same thing with the reindeer, because the last thing we would want is reindeer on cocaine, pulling Santa around the sky," said Cullen. 
 
 After administration of medetomidine anesthesia, the investigators performed similar evaluations of the reindeer nasal mucosa. They found an abundant microcirculation carrying a heavy concentration of red cells. Mean perfused vessel density was 20, as compared with 15 in the human volunteers. 
 
 The authors also evaluated the reindeer nasal microcirculation after the animals completed a treadmill test, which showed that "they do indeed have red noses. In addition to the nose having a high microvascular density, the nasal mucosa also revealed an abundance of ring-like vascular arrangements, similar to those in humans." 
 
 The study does not completely resolve questions surrounding the origin of Rudolph's red nose, according to Cullen. Noting that many human's noses turn red during alcohol consumption, he said the role of alcohol in Rudolph's bright red nose remains to be seen. 
 
 "It would have been interesting to see if giving the reindeer alcohol would have caused their noses to be redder and increased the blood flow," said Cullen. 
 
 If alcohol does play a role in the color of Rudolph's nose, the study has implications that extend beyond well beyond a single reindeer. 
 
 "I think [the message] will be 'Don't let Santa drive drunk,' because he won't be able to deliver the presents," said Cullen. 
 
 "Seriously, a lot of people leave out quick drinks for Santa and carrots for the reindeer, so I think maybe we should stick to healthier food and drink for both Santa and the reindeer." 
 
 The authors reported that Santa Claus offered "enthusiastic support" for this study. Ince disclosed that he is the inventor of sidestream dark field imaging technology and holds shares in MicroVision Medical. He once served as a consultant for the company. 
 
 1969-12-31T19:00:00-0500
– Everyone knows Rudolph the Red-Nosed Reindeer has "a very shiny nose" that even, some might say, "glows." But why? A new—and, The Local notes, tongue-in-cheek—investigation explains. Researchers in Norway and the Netherlands compared reindeer noses to human noses and found that reindeer have 25% more blood vessels in their nasal lining, which help control body temperature—an important task when you're flying all around the globe in a single evening. Researchers had reindeer walk on a treadmill, and observed that afterward, "they do indeed have red noses," MedPage Today reports. "Rudolph's nose is red because it is richly supplied with red blood cells, comprises a highly dense microcirculation, and is anatomically and physiologically adapted for reindeer to carry out their flying duties for Santa Claus," say the researchers. They also estimated that in order to get Christmas presents to everybody on time, Rudolph would have to lead Santa's team at 650 miles per second—a speed that would vaporize them, unless Rudolph could protect them with an ion shield.